Occult disease in normal-appearing peritoneum is common in epithelial ovarian cancer (EOC), especially after neoadjuvant chemotherapy (NACT). Pafolacianine (Cytalux) is the first Food and Drug Administration-approved agent for targeted imaging of EOC occult disease. The current study presents its first out-of-trial use during cytoreductive surgery (CRS). This study analyzed three cases of Cytalux application in patients with EOC and peritoneal metastases who underwent CRS and hyperthermic intraperitoneal chemoperfusion. Targeted imaging with Cytalux was performed before CRS to confirm uptake by visible lesions and after to identify occult disease. The association between Cytalux-positive disease and pathology was evaluated. Patient A had primary EOC and patients B and C had recurrent disease. All patients received NACT. Patient A had a peritoneal cancer index (PCI) of 21 and a completeness of cytoreduction (CC) score of 1, while patients B and C both had PCI 9 and CC score of 0. Cytalux imaging was associated with all macroscopic lesions. In patient A, Cytalux identified 16 additional peritoneal lesions with 14 confirmed as metastases [true positive (TP) rate, 87.5%]. Two Cytalux-positive peritoneal areas were fulgurated until the signal loss but subsequently tested positive for cancer. In patients B and C, Cytalux detected two lesions in each case with 50.0% positive on pathology. Overall peritoneal-level TP and false positive (FP) rates were 80.0 and 20.0%, respectively. Cytalux can help identify occult EOC peritoneal disease and manage questionable areas of post-chemotherapy fibrosis. However, the FP rate is considerable. Cytalux signal navigation should not be used for energy destruction of lesions until more data are available.

Complete cytoreductive surgery (CRS) is a gold standard in advanced ovarian cancer (OC) treatment, and most of the time, requires upper abdominal procedures. However, there is an enormous variation regarding the reported incidence of splenectomies, and the safety and prognosis of this procedure is largely unknown. The aim of this study was to evaluate the impact of splenectomy on surgical outcomes, complications and overall survival (OS) in primary OC surgery.

This prospective observational cohort study comprised patients with stage IIIC-IV OC who underwent primary CRS. Cases and controls were defined based on whether splenectomy had been performed or not. Comparisons between the groups were made using logistic regression models, receiver-operator characteristics and survival analyses i.e. Kaplan-Meier and Cox proportional hazard models.

Splenectomy was performed in 206/354 (58 %) patients, and among these - 170 (82.5 %) spleen metastases were identified. High peritoneal cancer index (PCI) was an independent predictor of splenectomy (aOR = 1.27 [95 % CI: 1.21-1.34]), with a PCI cut-off of 16 indicating need for splenectomy (AUC = 0.884). Splenectomy, PCI and surgical complexity score were all independent predictors of high-grade postoperative complications. Splenectomy, high PCI and completeness of cytoreduction were independent predictors of worse OS. Type of spleen metastasis (hilar/capsular versus parenchymal) did not influence OS.

Splenic metastatic involvement is common in OC and splenectomy is predicted by high PCI. Survival prognosis is equally impaired by all types of spleen metastasis. Splenectomy is an indicator of high tumour burden, high surgical complexity and high-grade postoperative complications, impaired survival and, indirectly, of cytoreduction success.

This study was aimed at evaluating the significance of 18F-fluorodeoxyglucose PET/computed tomography (FDG PET/CT) in the staging and differentiation of malignant peritoneal mesothelioma (MPeM).

We retrospectively analyzed clinical and imaging data of 21 women and 21 men with MPeM who underwent 18F-FDG PET/CT, and reviewed and analyzed 18F-FDG PET/CT characteristics of the patients. Standardized uptake values (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG = MTV × SUVmean) were determined for peritoneal lesions at the highest glycolysis point. Two experienced readers assessed tumor-node-metastasis (TNM) staging and peritoneal cancer index according to Peritoneal Surface Oncology Group International diagnostic requirements.

The SUVmax and MTV values were significantly lower for the epithelial cases than for the nonepithelioid cases, with the difference being significant (P < 0.05). The mean TLG value was significantly lower for the epithelial cases than for the nonepithelioid cases; however, the difference was NS (P > 0.05). Exploratory laparotomy was performed in 18 patients, the 18F-FDG PET/CT diagnostic accuracy for the T stage was 72.2%, and the TNM stage diagnostic accuracy was 94.4%. However, lymph node metastasis was more common in the biphasic type group, and metastasis was more often seen in the sarcomatoid type group.

Using a previously suggested novel approach for TNM staging in 18F-FDG PET/CT assessment of MPeM may improve the accuracy of staging; however, SUVmax values showed slight variations depending on the pathology type. 18F-FDG PET/CT can improve the accuracy of TNM staging, and SUVmax values vary slightly depending on the pathology type. Furthermore, 18F-FDG PET/CT can afford simultaneous visualization of lesions throughout the body, which can help develop a treatment strategy.

Prediction of open-close and long-term outcome is challenging in patients undergoing cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). Prognostic scores often include factors not known at baseline. Therefore, we aimed to analyze whether patterns of preoperative tumor markers could aid in prediction of open-close surgery and outcome in patients with pseudomyxoma peritonei (PMP) or colorectal peritoneal metastases (PM).

All patients accepted for CRS and HIPEC for PMP or colorectal PM at Uppsala University Hospital in 2013-2021 were included. The tumor markers CEA, CA19-9, CA125, CA72-4, and CA15-3 were clustered using the k-means algorithm; the average silhouette width determined the optimal numbers of clusters.

Clustering of patients with PMP (n = 138) and colorectal PM (n = 213) resulted in two clusters each. PMPCluster-1 (n = 124) had a 5-year overall survival (OS) of 77% (95% CI 69-85%), 11 (9%) open-close surgeries, and a median peritoneal cancer index (PCI) of 17. PMPCluster-2 (n = 14) patients had poorer prognosis (36%, 95% CI 15-85%, p = 0.003), more often open-close (n = 6, 43%, p = 0.002), and higher PCI (median 36, p < 0.001). ColorectalCluster-1 (n = 191) had a 5-year OS of 28% (95% CI 21-37%), median PCI of 11, and 38 (20%) open-close surgeries. ColorectalCluster-2 (n = 22) had poorer prognosis (10%, 95% CI 3-36%, p = 0.02), higher PCI (median 26, p < 0.001), higher completeness of cytoreduction score (p = 0.005), but no difference in open-close surgery (n = 6, 27%, p = 0.411). PMPCluster-2 and ColorectalCluster-2 were characterized by markedly elevated tumor markers. Open-close surgery was unusual in cases of normal CA72-4.

Elevation of several preoperative tumor markers is associated with poor prognosis and increased risk of open-close. CA72-4 deserves increased attention.

To evaluate the efficiency of 68Ga-FAPI-04 PET (PET/MRI or PET/CT) for N and M staging in gastric carcinoma and compare outcomes with histopathology and contrast-enhanced computed tomography (CECT).

Patients with gastric carcinoma who had undergone 68Ga-FAPI-04 PET/MRI or PET/CT before treatment were retrospectively enrolled. Histopathology post lymphadenectomy was the gold standard for N staging, while histopathology and follow-up data were the reference for overall outcomes. The diagnostic efficiency of 68Ga-FAPI-04 PET for detecting regional lymph node involvement and distant metastases was compared to that of CECT.

Sixty-two patients were enrolled. In 18 patients who underwent 68Ga-FAPI-04 PET/MRI and lymphadenectomy, 532 lymph nodes were dissected. 68Ga-FAPI-04 PET/MRI showed similar sensitivity, specificity, and accuracy compared to CECT (28.3% vs. 23.2%, 99.8% vs. 99.3%, and 86.5% vs. 85.2%, all P > 0.05). Fifty-five patients had regional lymph node metastasis, 68Ga-FAPI-04 PET exhibited comparable diagnostic efficiency to CECT, with sensitivity of 83.6% versus 87.3%, specificity of 100% versus 85.7%, accuracy of 85.5% versus 87.1% (all P > 0.05). Excluding 3 patients with only abdominal CECT, 32 out of 59 patients had distant metastasis, with no significant differences in sensitivity, specificity, and accuracy between 68Ga-FAPI-04 PET and CECT based on patient (100% vs. 87.5%, 92.6% vs. 96.3%, and 96.6% vs. 91.5%, all P >0.05). Notably, 68Ga-FAPI-04 PET outperformed CECT in detecting peritoneal, distant lymph nodes, bone, liver, and ovarian metastases by visualizing more lesions or greater lesion extent.

68Ga-FAPI-04 PET exhibits comparable diagnostic performance to CECT for patient-based N staging and M staging of gastric cancer. However, it surpasses CECT in visualizing distant metastases.

Diagnostic imaging of peritoneal metastases in ovarian and colorectal cancer remains pivotal in selecting the most appropriate treatment and balancing clinical benefit with treatment-related morbidity and mortality. To address the challenges related to diagnostic imaging and detecting and reporting peritoneal metastatic spread, a joint guideline was created by the European Society of Gastrointestinal and Abdominal Radiology (ESGAR), European Society of Urogenital Radiology (ESUR), Peritoneal Surface Oncology Group International (PSOGI), and European Association of Nuclear Medicine (EANM).

A targeted literature search was performed and consensus recommendations were proposed using Delphi questionnaires and a five-point Likert scale.

A total of three Delphi rounds were performed. Consensus was reached on the position of diagnostic imaging for assessment of operability, treatment response monitoring, and follow-up of peritoneal metastases, optimal imaging modality and their technical imaging requirements depending on the indication and how to optimise communication of imaging results by the report and multidisciplinary board discussion. The complete list of recommendations is provided.

These expert consensus statements aim to guide appropriate indications, acquisition, interpretation, and reporting of imaging for operability assessment, treatment response monitoring, and follow-up of peritoneal metastases in ovarian and colorectal cancer patients.

Question Staging peritoneal metastases (PM) helps to guide clinical decision-making for colorectal and ovarian cancer patients. How can we optimise the use of imaging techniques to assess PM? Findings Imaging plays a crucial role in the detection, operability assessment, treatment response monitoring, and follow-up of peritoneal metastases in colorectal and ovarian cancer patients. Clinical relevance These expert consensus statements aim to guide appropriate indication, acquisition, interpretation, and reporting of imaging for operability assessment, treatment response monitoring, and follow-up of peritoneal metastases in ovarian and colorectal cancer patients.

Hyperthermic intraperitoneal chemotherapy (HIPEC) combined with cytoreductive surgery (CRS) (CRS-HIPEC) has revolutionized the management of peritoneal malignancies, pivoting from a palliative care approach to a treatment strategy tailored to improve overall survival. This procedure is based on the principle that local instillation of heated chemotherapeutic agents augments their cytotoxic effects, which target and eradicate microscopic disease. Imaging is integral to the management of patients undergoing HIPEC, having multiple roles that range from patient selection, preoperative assessment, and determining treatment effectiveness to postprocedural surveillance. Various imaging modalities can be used for radiologic assessment and include CT, dual-energy CT, MRI, fluorine 18-fluorodeoxyglucose PET/CT, and PET/MRI. A crucial step in assessing the feasibility of CRS-HIPEC is estimation of the peritoneal carcinomatosis index, which enables one to determine the total peritoneal disease burden and is essential for effective multidisciplinary management. Following HIPEC, the completeness of cytoreduction score and residual disease score provide a robust framework for assessing treatment efficacy and strategically guiding subsequent management and surveillance protocols. Imaging facilitates accurate evaluation of complications, as well as early recognition of residual or recurrent peritoneal disease. The authors provide a comprehensive overview of HIPEC therapy, focusing on the role of imaging in the management of patients with peritoneal malignancies, delving into the nuances of this procedure, and discussing crucial aspects related to patient selection, surgical complexity, and prediction of outcomes. ©RSNA, 2025 See the invited commentary by Wasif in this issue.

Peritoneal disease can be classified as either benign or malignant in nature. Malignant peritoneal disease can be further considered as either primary or secondary in origin. Primary peritoneal malignancy includes peritoneal mesothelioma, serous carcinoma, and desmoplastic small round cell tumour. Peritoneal carcinomatosis is the most commonly encountered secondary malignant peritoneal disease, typically of ovarian, gastric, colorectal, pancreatic, small bowel neuroendocrine, or breast origin. Others include peritoneal lymphomatosis and sarcomatosis. Benign peritoneal pathology may mimic malignant disease. Differentiating benign from malignant peritoneal pathology can be challenging, but is critical to guide appropriate care and avoid unnecessary intervention. Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) offers potentially curative treatment for patients with peritoneal carcinomatosis, pseudomyxoma peritonei, and peritoneal mesothelioma. For such patients, the radiologist provides crucial pre-operative information highlighting sites of disease involvement, particularly for sites which are challenging to assess at laparotomy or laparoscopy, including the hepatic dome, subdiaphragmatic space and mesenteric root. The radiologist is also essential to identify potential contraindications to surgery, as well as interpreting normal post-operative appearances, complications and assessing for disease recurrence.

Peritoneal carcinomatosis (PC) represents a challenge in the management of metastatic colorectal cancer (mCRC) because of the difficulties in diagnosis, tumor burden assessment, and in selecting the optimal treatments. A critical limitation is the lack of robust prognostic and predictive biomarkers, largely relying on serum markers (e.g., carcinoembryonic antigen) or the peritoneal carcinomatosis index (PCI) for disease extent. Circulating tumor DNA (ctDNA)-genomic fragments shed by tumor cells into the bloodstream-is now recommended by international guidelines for mCRC management. Its potential extends to PC, where it may enhance diagnostic, therapeutic, and follow-up strategies. However, PC from CRC (PC-CRC) is associated with lower ctDNA levels and detection rates compared to other metastatic sites, posing a challenge for its clinical utility. To address these limitations, peritoneal fluid analysis has emerged as a promising alternative, with peritoneal tumor DNA (ptDNA) detected at higher concentrations in this anatomical space. Integrating ctDNA and ptDNA may offer a deeper understanding of PC-CRC biology and provide more precise tools for managing this complex disease. This approach has the potential to revolutionize the treatment paradigm for PC-CRC, bringing precision medicine even to this subgroup of patients traditionally associated with poor outcomes. This review aims to evaluate the diagnostic, prognostic, and therapeutic implications of ctDNA and ptDNA in PC-CRC, highlighting current limitations and future directions.

Sarcopenia has recently been gaining importance due to its role on mortality and mobility in diseases and operations. In this study, we aimed to evaluate the effect of sarcopenia on major postoperative complications in patients undergoing cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for peritoneal surface malignancy.

In this longitudinal cohort study included 202 patients treated between January 2018 and September 2023, with 52 undergoing prophylactic procedures. Peritoneal metastases originated from colorectal, gastric, and ovarian cancer; peritoneal mesothelioma; mucinous adenocarcinoma of the appendix; and endometrial cancer. Age, sex, body mass index (BMI), length of hospital stay (LOS), peritoneal cancer index (PCI), competency of cytoreduction (CC), operation time, and primary peritoneal carcinomatosis were recorded. All variables were analyzed according to the presence of major complications and sarcopenia.

Significant associations were found between major complications and sarcopenia (p = 0.002), PCI (p = 0.036), operation time (p = 0.015), and LOS (p < 0.001). In sarcopenic patients, significant associations were found with sex (p = 0.035), age (p = 0.025), and BMI (p = 0.001). Multivariate Cox regression analysis identified sarcopenia as an independent risk factor for major complications, tripling the likelihood (p = 0.005). Additionally, PCI score (p = 0.008) and LOS (p < 0.001) were independent risk factors.

This study underscores sarcopenia as an independent risk factor for major complications in CRS/HIPEC patients, with PCI and LOS as additional risk factors. In sarcopenic patients, pre-operative evaluation should be done carefully and post-operative risks should be kept in mind.

Repeat cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) (rCRS-HIPEC) has improved the long-term survival of select patients with acceptable perioperative morbidity and mortality. The pattern of peritoneal disease recurrence is critical in determining eligibility for rCRS-HIPEC. This study evaluated the accuracy, sensitivity and specificity of the radiological peritoneal cancer index (PCI) across different imaging modalities in rCRS-HIPEC patients.

This was a retrospective study on patients with peritoneal disease recurrence who underwent rCRS-HIPEC between January 2022 to December 2023. The accuracy, sensitivity, and specificity of the radiological PCI in predicting the surgical PCI was calculated overall and for each imaging modality at each abdominal region.

32 patients were included in this study. The accuracy, sensitivity and specificity of the overall radiological PCI was 63.0%, 30.8% and 79.9%, respectively. Accuracy (67.5 vs. 62.6%) and specificity (84.8% vs. 75.8%) were higher in FDG-PET versus CT. The sensitivities of all imaging modalities were low (CT 34.9%, FDG-PET 33.3%). FDG-PET and CT had high sensitivities in detecting pelvic disease (80% and 87.5%) but low sensitivities in identifying small bowel (25-33.3% for both modalities) and epigastric disease (25% and 0%). For each abdominal region, the difference between radiological and surgical PCI did not differ significantly based on imaging modality.

Overall, the radiological PCI has a good specificity in rCRS-HIPEC patients and should be used to guide perioperative decision-making. FDG-PET had superior accuracy and specificity in comparison to CT in detecting peritoneal disease recurrence.

To investigate the prognostic value of the apparent diffusion coefficient (ADC) calculated from diffusion-weighted imaging (DWI) to cytoreductive surgery (CRS), with or without hyperthermic intraperitoneal chemotherapy (HIPEC), for gastric cancer (GC) patients with peritoneal metastasis (PM).

Between May 2016 and December 2020, 95 newly diagnosed GC patients with PM who underwent CRS combined with HIPEC (CRS + HIPEC group, n = 61) and CRS alone (CRS group, n = 34) were retrospectively included. All patients underwent abdominal 3.0 T MRI scan, including DWI, and the mean ADC (ADCmean), minimum ADC (ADCmin), and maximum ADC (ADCmax) values of the whole-volume tumor were measured. The prognostic value of the ADC parameters and clinical and histopathological characteristics were investigated by univariate and multivariate Cox analyses.

The median overall survival (OS) periods of the CRS + HIPEC and CRS groups were 18 and 9 months, respectively ([hazard ratio (HR) = 0.44 [95% CI: 0.27-0.71], P<0.001). The ADCmean and ADCmin values were positively correlated with OS in all patients (Spearman's rho [R] = 0.361 and 0.470), as well as in the CRS + HIPEC (R = 0.369 and 0.417) and CRS (R = 0.192 and 0.409) groups. The multivariate Cox analysis demonstrated that the ADCmean ≤ 1.39 × 10- 3 mm2/s and ADCmin ≤ 0.77 × 10- 3 mm2/s were significantly associated with a negative prognosis in the total population (HR = 1.68 [95% CI: 1.02-2.75] and 2.48 [95% CI: 1.51-4.08], P all < 0.05) and the CRS + HIPEC group (HR = 2.22 [95% CI: 1.19-4.14] and 2.37 [95% CI: 1.26-4.37], P all < 0.05), along with pathologic T and N stages. Only the ADCmin ≤ 0.77 × 10- 3 mm2/s was identified as an independent prognostic factor in the CRS group (HR = 3.49 [95% CI: 1.19-10.20], P = 0.022).

The minimum ADC was identified as a strong independent prognostic factor for GC patients with PM who underwent CRS, with or without HIPEC.

Tumours of the appendix - a vestigial digestive organ attached to the colon - are rare. Although we estimate that around 3,000 new appendiceal cancer cases are diagnosed annually in the USA, the challenges of accurately diagnosing and identifying this tumour type suggest that this number may underestimate true population incidence. In the current absence of disease-specific screening and diagnostic imaging modalities, or well-established risk factors, the incidental discovery of appendix tumours is often prompted by acute presentations mimicking appendicitis or when the tumour has already spread into the abdominal cavity - wherein the potential misclassification of appendiceal tumours as malignancies of the colon and ovaries also increases. Notwithstanding these diagnostic difficulties, our understanding of appendix carcinogenesis has advanced in recent years. However, there persist considerable challenges to accelerating the pace of research discoveries towards the path to improved treatments and cures for patients with this group of orphan malignancies. The premise of this Expert Recommendation article is to discuss the current state of the field, to delineate unique challenges for the study of appendiceal tumours, and to propose key priority research areas that will deliver a more complete picture of appendix carcinogenesis and metastasis. The Appendix Cancer Pseudomyxoma Peritonei (ACPMP) Research Foundation Scientific Think Tank delivered a consensus of core research priorities for appendiceal tumours that are poised to be ground-breaking and transformative for scientific discovery and innovation. On the basis of these six research areas, here, we define the first 'cells to society' research framework for appendix tumours.

Cytoreductive surgery-hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) candidates often have extraperitoneal abdominal disease. Current expert peritoneal surface malignancy (PSM) guidelines recommend that the presence of extraperitoneal disease is a contraindication to CRS-HIPEC.

We conducted a retrospective review of our institutional appendiceal and colorectal CRS-HIPEC registries. Two study cohorts were constructed: (1) cytoreduction with extraperitoneal abdominal disease, and (2) cytoreductions limited to peritoneal structures alone. The primary study outcome was survival. Subgroup analysis was based on the primary tumor and completeness of cytoreduction.

Overall, 864 CRS-HIPEC cases were evaluated, consisting of 578 appendiceal primaries and 286 colorectal cancers. The extraperitoneal cohort included 101 patients, with 763 patients in the non-extraperitoneal group. The median follow-up time was 13.18 years. The main analysis showed no significant differences in survival times. For overall survival (OS) there was a mean OS time of 5.87 years and a median OS time of 4.43 years for extraperitoneal cytoreductions compared with a mean of 5.90 years and a median of 4.76 years for non-extraperitoneal cytoreductions (p = 0.955). Five-year OS rates did not differ at 49.1% versus 49.5% (odds ratio [OR] 1.036, 95% confidence interval [CI] 0.671-1.597, p = 0.874). Disease-free survival (DFS) times showed a mean of 4.40 years and a median of 1.93 years for extraperitoneal cases versus a mean of 5.44 years and a median of 3.05 years for non-extraperitoneal cases (p = 0.210). Five-year DFS rates also showed no differences (OR 0.894, 95% CI 0.476-1.681, p = 0.728). No significant differences in progression-free survival (PFS)Pp times (p = 0.061) were reported. Multivariate Cox regression analysis indicated that extraperitoneal CRS was not an independent predictor of OS (hazard ratio [HR] 1.281, 95% CI 0.885-1.854, p = 0.190), DFS (HR 1.087, 95% CI 0.694-1.701, p = 0.716), or PFS (HR 0.650, 95% CI 0.243-1.738).

We conducted the largest analysis evaluating extraperitoneal cytoreductions, with no significant differences in almost all survival outcomes. We propose that the presence of extraperitoneal abdominal disease is not a contraindication to proceeding with CRS-HIPEC.

The Peritoneal Cancer Index (PCI), calculated intraoperatively, has previously yielded mixed results when correlated with computed tomography. This study aimed to quantify variation in this scoring method comparing radiologists' and surgeons' radiologic PCI (rPCI) assessment.

The rPCI of 104 patients treated at a single institution for peritoneal carcinomatosis was calculated by an abdominal radiologist and a surgeon. An additional 36-patient cohort was studied to compare preoperative rPCI with intraoperative gold standard PCI. Agreement was compared using kappa statistics.

The rPCI of the 104 patients studied ranged from 2 to 39 (median, 12; interquartile range [IQR], 6-23) by the radiologist's analysis and 2 to 37 (median, 9; IQR, 6-15) by the surgeon's analysis. There was good agreement for PCI cutoffs of 15 (77.48%; kappa, 0.40) and 20 (78.63%; kappa, 0.24). The 36-patient cohort undergoing surgical exploration showed a median rPCI of 4 (IQR, 2-5.75) and a median intraoperative PCI of 11 (IQR, 6-12), with a significant difference in score by method (p < 0.001, Wilcoxon signed-rank test).

For rPCI cutoffs greater than 15 and 20, the surgeon's and radiologist's rPCI showed strong concordance, denoting the interobserver reproducibility of rPCI. Moreover, concordance with intraoperative PCI translated to radiographic assessment. The rPCI consistently underestimated intraoperative PCI, suggesting that rPCI may be a useful conservative tool for assessing peritoneal burden. Although surgical exploration is needed to "rule in" patients as candidates for CRS, the authors suggest that rPCI can be used to "rule out" patients as CRS candidates based on institutional PCI cutoffs.

Peritoneal mesothelioma (PM) is a rare disease with various histopathological subtypes. For malignant peritoneal mesothelioma and borderline subgroups locoregional therapy with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) has been implemented. The aim of our study was to retrospectively present the outcome after CRS and HIPEC for patients with different subtypes of peritoneal mesothelioma.

In total 15 patients received CRS and HIPEC due to peritoneal mesothelioma at our tertiary referral hospital between 2013 and 2022. Surgical and oncologic outcomes of 14 of those patients were retrospectively evaluated as one patient was lost to follow-up.

The cohort consisted of 9 patients with diffuse malignant peritoneal mesothelioma (64.3%), 3 patients with multicystic peritoneal mesothelioma (21.4%) and 2 patients with well-differentiated peritoneal mesothelioma (14.3%). Complete cytoreduction was possible in 85.7% (n = 12). The major complication rate was 28.6% (n = 4) and the reoperation rate was 14.3% (n = 2). Median follow-up was 55 months (standard error, SE 15.0%, 95% confidence interval, CI 25.6-84.4 months). Over this time period 64.3% (n = 9) had no evidence of disease, 21.4% (n = 3) were alive with disease and 14.3% (n = 2) died of peritoneal mesothelioma. The median recurrence-free survival of patients was 13 months (SE 13.0%, 95% CI 0.0-32.2 months). None of the patients with multicystic peritoneal mesothelioma had evidence of disease at the time of last follow-up.

Patients with peritoneal mesothelioma should receive locoregional treatment as good oncological results can be achieved with reasonable postoperative morbidity. Thus, awareness is necessary for this rare but potentially aggressive disease to offer the best medical care.

Peritoneal, pericardial and pleural mesothelioma (PeM/PcM/PM) are rare and aggressive diseases with limited survival. Molecularly guided therapy is currently not part of standard care.

This study integrates molecular and clinical data from 51 patients (among them 28 PM, one PcM, 21 PeM and one synchronous PeM/PM) enrolled in the National Center for Tumor Diseases and the German Cancer Consortium (NCT/DKTK) Molecularly Aided Stratification for Tumor Eradication Research (MASTER), a multicenter precision oncology registry trial addressing adults with rare advanced-stage cancers. Analysis comprised both somatic and germline whole exome sequencing/whole genome sequencing and transcriptome analysis leading to personalized treatment recommendations issued by a dedicated molecular tumor board. To assess clinical efficacy, progression-free survival (PFS) ratios comparing molecularly informed therapies (PFS2) to preceding systemic therapies (PFS1) were calculated. Efficacy of immune checkpoint inhibition applied during the observation period was assessed accordingly.

Cancer-related genes altered in more than 5 out of 44 assessable patients were BAP1, CDKN2A, NF2, SETD2 and TP53. Somatic (n = 23) or germline (n = 9) alterations in homologous recombination-related genes were detected in 27/44 patients. In 21/44 cases, they were supported by positive combined homologous recombination deficiency scores or BRCAness signature. Following American College of Medical Genetics and Genomics guidelines, (likely) pathogenic germline variants in autosomal dominant cancer predisposition genes were found in 8/51 patients. Molecular tumor board recommendations were issued in 46 cases and applied in 6 cases. Mean PFS ratio was 2.45 (n = 5). Median PFS2 was 6.5 months (n = 6), median PFS1 was 4.0 months (n = 5). A total of 27 patients received immune checkpoint inhibition during the observation period leading to a mean PFS ratio of 1.69 (n = 19).

In mesothelioma, comprehensive molecular analysis can provide valuable clinically actionable information. Molecularly informed therapy recommendations can lead to clinical benefit.

Primary diffuse malignant peritoneal mesothelioma (MPEM) is a malignant disease without standard treatments recommended. Recently, immunotherapy has revolutionized the field of tumor therapy. According to current clinical evidence, advanced MPEM may gain potential clinical benefits from immune checkpoint inhibitors. The present study reported a 61-year-old female patient with persistent low fever as the initial symptom, who was eventually diagnosed with MPEM. This patient obtained significant clinical benefits from pembrolizumab, with disappearance of symptoms, a lasting stable disease response with a progression-free survival of 10.0 months and a long overall survival of 26.2 months. The application of pembrolizumab was explored as an emerging effective treatment for patients with MPEM. In addition, the clinical characteristics, diagnosis, treatment, pathogenesis and target regulation in MPEM were discussed and previous studies were reviewed. Further evidence is needed from future extensive clinical trials.

Pseudomyxoma peritonei (PMP) is a condition characterised by the presence of gelatinous tumour-like growth within the peritoneal cavity. Combined cytoreductive surgery and intraperitoneal chemotherapy have shown to improve the survival rate in PMP patients. However, post-operative complications such as cognitive dysfunction, respiratory insufficiency and acute renal failure are still observed. This retrospective study aims to explore the risk factors associated with major post-operative complications and specifically investigate the correlation with intraoperative hypotension.

This retrospective cohort study included PMP patients treated at Beijing Aerospace Center Hospital from 1 June, 2014 to 30 December, 2020. The primary outcome measures were major post-operative complications, including neurological, pulmonary, cardiovascular, surgical complications, acute hepatic injury and acute kidney injuries. The secondary outcome measures included infection, fever and deep venous thrombosis. Statistical analysis was conducted using EmpowerStats and R software.

A total of 782 patients were screened, and 668 patients were included in the statistical analysis. Amongst them, 234 (35.03%) individuals experienced major post-operative complications. Factors such as pre-operative American Society of Anaesthesiologists grading, age, haemoglobin and albumin levels, intraoperative mean arterial pressure, blood loss, fluid replacement volume, method of intraperitoneal hyperthermic perfusion and post-operative requirement for intensive care unit mechanical ventilation were found to be correlated with major complications.

The identified risk factors provide valuable insights for improving clinical pathways in the management of PMP. Further prospective studies are warranted to establish the association between these factors and patient outcomes.

Gastric cancer is a major cause of cancer mortality, with poorer prognosis in the presence of peritoneal metastases as low as 2.8-9 months. Systemic therapy has a limited role. Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) have been shown to improve survival. This study evaluates survival of patients with gastric cancer and peritoneal metastases (GCPM) undergoing CRS and HIPEC at an Australian centre.

A retrospective analysis was conducted on a prospectively collected database of patients who underwent CRS and HIPEC for GCPM from January 2009 to December 2023. Data included demographics, perioperative factors, histopathology and survival.

Twenty-four patients were identified, with median postoperative overall survival of 11.7 months (95% CI 8.6-34.2 months). Most patients had poorly differentiated adenocarcinoma (n = 23, 96%), with 14 (58%) exhibiting signet cell pathology. 62% (n = 15) received preoperative chemotherapy. Median PCI was 5, with a CC score of 0 in 96% of patients (n = 23). Clavien-Dindo III/IV morbidity was noted in 8 patients (33%) with no perioperative mortality. No survival differences were found between those with signet cell pathology and those without (10.6 vs. 11.7 months, p = 0.83), nor between those receiving preoperative chemotherapy and those who did not (11.7 vs. 10.6 months, p = 0.60). Age, sex, PCI, CC and tumour markers demonstrated correlations with survival in linear regression, but no individual factor significantly influenced outcomes.

CRS and HIPEC for low volume GCPM should be considered in select patients.

To assess the feasibility of scoring extragastric vascular invasion and occult peritoneal metastasis using preoperative computed tomography (CT) images of gastric cancer (GC) and to explore the correlation between these scores and patient prognosis.

587 GC patients with CT scans from two centers, all confirmed by pathology, were retrospectively evaluated. Scores for CT-detected blood vessel invasion (ctBVI), lymphatic invasion (ctLVI), and occult peritoneal metastasis (ctOPM) were assigned based on preoperative CT images. The patients' follow-up provided data on overall and disease-free survival. Cox proportional hazard models were used to analyze prognostic factors.

The inter-group and intra-group consistency of ctBVL, ctLVI, and ctOPM scores were all > 0.70. Log-rank analysis demonstrated a statistically significant difference in survival curves (p < 0.001). CtBVL, ctLVI, and ctOPM scores were related to overall survival (OS) and disease-free survival (DFS). Univariate and multivariate Cox regression analyses identified ctBVL, ctLVI, ctOPM scores as independent risk factors for GC prognosis. In multivariate analysis, the three sign scores were related to DFS (p < 0.05), with ctBVL (hazard ratio (HR) = 1.980, 95% CI: 1.336-2.933), ctLVI (HR = 1.502, 95% CI: 1.336-2.933), and ctOPM (HR = 1.182, 95% CI: 0.886-1.578). The three scores were also correlated with OS (p < 0.05), ctBVL (HR = 2.003, 95% CI: 1.278-3.139), ctLVI (HR = 1.523, 95% CI:1.055-2.200) and ctOPM (HR = 1.289, 95% CI: 1.013-1.770).

CtBVL, ctLVI, and ctOPM scores are valuable prognostic indicators in gastric cancer, influencing both OS and DFS.

Question To study whether the ctBVL, ctLVI, and ctOPM scores assessed by preoperative enhanced CT imaging can predict the survival outcomes of patients. Findings CtBVL, ctLVI, and ctOPM scores, assessed via preoperative enhanced CT imaging, are associated with worse survival outcomes when elevated. Clinical relevance CtBVL, ctLVI, and ctOPM scores may help guide personalized follow-up plans. Patients with higher scores might require closer monitoring and more aggressive treatment.

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) enable effective management of colorectal and appendiceal peritoneal metastases (CAPM) despite high morbidity. This study aimed to evaluate the role of repeat diagnostic laparoscopy (rDL) after systemic ± intraperitoneal chemotherapy in the management of initially unresectable CAPM.

This retrospective cohort study included 70 consecutive patients with CAPM who underwent initial diagnostic laparoscopy (iDL). Patients with inoperable or equivocal CAPM underwent chemotherapy followed by rDL to assess the treatment response and possibility of conversion to CRS and HIPEC.

Cytoreductive surgery was deemed feasible for 29 patients and unlikely or equivocal for 41 patients based on iDL. Of the 29 resectable patients, 24 successfully underwent CRS and HIPEC after neoadjuvant chemotherapy. Among the 41 patients initially considered unresectable, 16 were deemed operable based on rDL after chemotherapy, and CRS and HIPEC were achieved for 14 patients (conversion). The median peritoneal cancer index was significantly reduced after chemotherapy for the 14 "conversion" patients, from 16 based on iDL to 11 based on rDL (p < 0.05). The conversion rate was 34% (14/41), with a 5-year survival rate of 14%. Treatment with CRS and HIPEC was achieved for 38 of 45 patients deemed operable based on either iDL or rDL (worst-case estimated positive predictive value, 84%).

Diagnostic laparoscopy is useful in predicting the likelihood of achieving CRS for patients with CAPM. Despite inoperability based on iDL, patients should be considered for rDL after chemotherapy to assess the possibility of conversion to CRS and HIPEC.

Colorectal cancer (CRC) with peritoneal metastasis (PM) is associated with poor prognosis. The Peritoneal Cancer Index (PCI) is used to evaluate the extent of PM and to select Cytoreductive Surgery (CRS). However, PCI score is not accurate to guide patient's selection for CRS.

We have developed a novel AI framework of decoupling feature alignment and fusion (DeAF) by deep learning to aid selection of PM patients and predict surgical completeness of CRS.

186 CRC patients with PM recruited from four tertiary hospitals were enrolled. In the training cohort, deep learning was used to train the DeAF model using Simsiam algorithms by contrast CT images and then fuse clinicopathological parameters to increase performance. The accuracy, sensitivity, specificity, and AUC by ROC were evaluated both in the internal validation cohort and three external cohorts.

The DeAF model demonstrated a robust accuracy to predict the completeness of CRS with AUC of 0.9 (95 % CI: 0.793-1.000) in internal validation cohort. The model can guide selection of suitable patients and predict potential benefits from CRS. The high predictive performance in predicting CRS completeness were validated in three external cohorts with AUC values of 0.906(95 % CI: 0.812-1.000), 0.960(95 % CI: 0.885-1.000), and 0.933 (95 % CI: 0.791-1.000), respectively.

The novel DeAF framework can aid surgeons to select suitable PM patients for CRS and predict the completeness of CRS. The model can change surgical decision-making and provide potential benefits for PM patients.

Background/Objectives: Hyperthermic intraperitoneal chemotherapy (HIPEC) with cytoreductive surgery (CRS) has been reported to improve survival in patients with peritoneal carcinomatosis. This study aimed to investigate the morbidity and mortality rates of CRS with HIPEC in patients with ovarian cancers. Methods: We retrospectively reviewed the medical records of patients who underwent CRS with HIPEC for ovarian cancer from January 2013 to July 2021 at two tertiary institutions. The morbidities and mortalities that occurred within 30 days after HIPEC and the clinical and operative factors related to morbidities were investigated. Results: A total of 155 procedures in 151 patients were included in this study. The median age was 55 years and the median score of the peritoneal carcinomatosis index was eight points. Morbidities of grade ≥3 within 30 days of HIPEC occurred in 18 patients (11.6%). The most common severe morbidity was wound infection (3.2%), followed by pleural effusion (1.9%) and postoperative hemorrhage (1.9%). Within the 30-day postoperative period, there were no reported mortality cases. There were statistical differences in age, length of stay, peritoneal carcinomatosis index, bowel resection, operation time, and completeness of cytoreduction between the patients and severe morbidity. However, in the multivariate logistic analysis, none of the factors showed a statistically significant relationship with the occurrence of severe morbidity. Conclusions: The morbidity and mortality rates of CRS with HIPEC in gynecologic cancer patients were relatively low compared to those in previous reports. Further studies about the possible risk factors are needed.

Selection of suitable candidates for intraoperative tumour detection and cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) is important for improving outcomes for patients with colorectal peritoneal metastases. Previous research demonstrated the use of single-photon emission computed tomography (SPECT), intraoperative radiodetection, and near-infrared fluorescence (NIRF)-guided surgery with a dual-labelled 111In-labelled dodecane tetra-acetic acid (DOTA)-labetuzumab-IRDye800CW tracer to detect peritoneal metastases before operation. The aim of this study was to validate these results.

A single-centre phase II study was conducted to evaluate the safety and feasibility of 111In-labelled DOTA-labetuzumab-IRDye800CW in patients with colorectal peritoneal metastases undergoing CRS-HIPEC. SPECT/computed tomography (CT) was undertaken before surgery, after intravenous administration of 10 mg 111In-labelled DOTA-labetuzumab-IRDye800CW (mean 101.25 MBq). During surgery, radiodetection and NIRF imaging were used for tumour detection. Adverse events were assessed, and tumour-to-background ratios (TBRs) and peritoneal cancer index scores were analysed.

Seven patients were included. No study-related severe adverse events were reported. Imaging before surgery revealed previously undetected metastases in one patient. The mean(standard deviation, s.d.) SPECT/CT peritoneal cancer index score was 3(2), and the intraoperative score was 14(7) (P = 0.032). A total of 52 lesions were removed during CRS, of which 37 were malignant. With NIRF imaging, 34 (92%) of 37 malignant lesions were detectable. Of 52 fluorescent lesions, 4 were false-positive. Mean(s.d.) fluorescence TBR was 3.4(1.8) and mean radiodetection TBR was 4.4(1.4).

This study confirmed the safety and feasibility of multimodal image-guided surgery in patients with peritoneal metastases.

Histologic grade is a key predictor for pseudomyxoma peritonei (PMP) of appendiceal origin that is used to guide clinical management. However, some tumors demonstrate disease behavior that deviates from their histologic grade. A recent study suggested that TP53, GNAS , and RAS mutation analysis could stratify tumors into distinct molecular groups with different prognosis. We investigated molecular alterations in 114 patients with PMP of appendiceal origin who were uniformly treated with cytoreductive surgery with intraperitoneal chemotherapy (CRS+IPCT). Tumors were separated into 4 groups based on their predominant genomic alteration: RAS -mut, GNAS -mut, TP53 -mut, and triple-negative ( RAS/GNAS/TP53 -wildtype). The results were correlated with World Health Organization (WHO) grade, peritoneal carcinomatosis index (PCI), completeness of cytoreduction (CC) score, and overall survival (OS) from the time of CRS+IPCT using multivariate Cox proportional hazard analysis. Fifty percent of TP53 -mut were WHO grade 3 compared with 38% triple-negative, 10% RAS -mut, and 7% GNAS -mut tumors ( P <0.001). The TP53 -mut group exhibited a significantly reduced OS compared with other groups ( P <0.001). No significant OS difference was identified between RAS -mut, GNAS -mut, and triple-negative groups ( P >0.05). In grade 3 PMP, TP53 -mut was significantly associated with reduced OS ( P =0.002). In the multivariate analysis for OS after CRS+IPCT, TP53 -mut [hazard ratio (HR) 3.23, P =0.004] and WHO grade (grade 2 HR 2.73, P =0.03 and grade 3 HR 5.67, P <0.001) were the only independent predictors of survival. Our results suggest that, in addition to tumor grade, TP53 status may help to provide a more patient-centered approach in guiding therapy in PMP.

Appendiceal adenocarcinoma represents a diagnostic and therapeutic challenge since it is prone to early lymphatic and peritoneal spread. We aimed to analyze the proportion of lymph node metastases in completion right hemicolectomy specimens, risk factors for peritoneal metastases (PM), and prognosis after definitive treatment.

Ninety-three patients with appendiceal adenocarcinoma scheduled for cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS + HIPEC) in Uppsala 2004-2020 were identified from a prospectively maintained registry. Risk factors for PM were assessed based on the presence (CT + group, n = 55) or absence (CT - group, n = 37) of visible PM at baseline CT scan. Prognostic factors were analyzed based on the actual presence (PM group, n = 66) or absence (no PM group, n = 27) of PM.

The median age was 60 (26-78). Forty-eight patients were women. Resection of PM at initial surgery indicated an 80 % risk of finding PM at a follow-up exploration. R1 appendectomy and perforated appendix had a similar risk for PM (24 %,26 %) which increased to 38 % if both were present. Regional lymph node metastases occurred in 31 % in the CT + group vs. 14 % in the CT - group (p = 0.005) and was associated with poor survival HR 5.16 (1.49-17.81). The 5-year OS and DFS rates were 54 % and 29 % in the PM group.

Patients with certain risk factors have a high likelihood of PM despite a normal CT scan, which justifies selective exploration at a HIPEC center. Regional lymph node spread supports the current practice of completion right hemicolectomy and is a significant prognostic factor.

Colorectal cancer (CRC) is a common malignancy with the propensity to metastasize. Common sites of metastasis include the liver, lungs, and peritoneum, with peritoneal metastases (PMs) having the worst prognosis. Unfortunately, systemic chemotherapy is often less effective in the treatment of PMs. Therefore, removal of all visible tumor via cytoreductive surgery along with intraperitoneal (IP) therapies has been used.

A comprehensive review of the literature was conducted using MEDLINE/PubMed and Web of Science with an end date of September 1, 2024, regarding cytoreductive surgery and heated IP chemotherapy for CRC PMs.

Recent studies have called into question the utility of IP chemotherapy in the treatment of CRC PMs. However, regardless of IP chemotherapy, cytoreductive surgery has demonstrated an additional survival benefit for patients with PM secondary to CRC.

This study reviews the pathophysiology of CRC PM, the current treatment paradigms, and a pathway for improving outcomes in patients with CRC PM.

The main prognostic factor for peritoneal metastasis (PM) is the complete resection of the disease during cytoreductive surgery. Accurate patient selection is therefore essential for determining eligibility for this type of surgery. The peritoneal carcinomatosis index (PCI) is a widely used tool for assessing the extent of carcinomatosis. This study aimed to evaluate the inter-observer reproducibility of PCI assessments via laparoscopy and identify factors influencing this reproducibility.

Between November 2020 and November 2022, 25 laparoscopic PCI assessment videos were reviewed by six surgeons from two centers. The total PCI score, regional PCI scores, and the number of visualized PCI areas were recorded. Inter-observer concordance was analyzed.

The median PCI score was 12 out of 39 (range 0-39), and the median number of visualized PCI regions was 10 out of 13 (range 1-13). The intraclass correlation coefficient (ICC) for the total PCI score was 0.846 (95 % CI 0.738, 0.927). A history of abdominal surgery significantly impacted PCI assessment reproducibility (p=0.029).

This study found a high inter-observer concordance in laparoscopic PCI assessments. Previous abdominal surgery negatively affected reproducibility, highlighting a challenge in evaluating the PCI in these patients.

The prognosis of patients with peritoneal metastases (PM) is poor, and these patients have a brief overall survival. Most patients with advanced PM receive palliative therapy to maintain their quality of life. In our current study, we investigated whether patient-specific 3D-tissue slices from patients with PM subjected to pressurized intraperitoneal aerosol chemotherapy could be cultured in vitro.

Biopsies from gastric cancer patients with PM were characterized for cytokeratin-positive tumor cells and the proliferation marker Ki-67. Biopsies from seven patients were cut to 350 µM thick slices in a standardized manner, cultured with 10 µM 5-fluorouracil, doxorubicin, cisplatin, oxaliplatin, or irinotecan for 96 h, and then examined histopathologically and via immunohistochemistry for persistent cytokeratin and Ki-67 expression.

In vitro cultured slices revealed a similar morphology to un-cultured specimens, and Ki-67-positive tumor cell areas were present after 96 h. The total amount of tumor cells per slice was determined by pan-cytokeratin staining. In the doxorubicin-treated slices, the cytokeratin-positive tumor cell fraction and proliferative (Ki-67pos) cells were decreased. Patient-specific 3D-tissue-slice cultures from peritoneal biopsies were cultured in vitro for up to 4 days.

Potentially, these cultures are a reliable model to evaluate the chemosensitivity of patients with PM. Further investigation is needed to match the chemosensitivity with the clinical course of these patients.

Peritoneal malignancies encompass a diverse range of tumors originating within the peritoneum, including primary tumors such as mesothelioma and primary serous peritoneal carcinoma or secondary tumors resulting from the spread of cancers from gastrointestinal, gynecological, and extra-abdominal sources. The traditional approach of palliative care for these malignancies is being replaced by a multimodal strategies that integrates surgery with systemic or intraperitoneal chemotherapy. Notably, cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy has shown significant improvements in survival rates. Imaging is crucial in the multidisciplinary management of these tumors, aiding in diagnosis, staging, restaging, and monitoring therapy response. It is also vital for appropriate patient selection, using the acronym "PAUSE", which involves assessing tumor burden via the peritoneal carcinomatosis index, evaluating patients pre- and post-therapy, detecting complications following therapy, and predicting treatment outcomes. This review explores the imaging manifestations of peritoneal malignancies, distinguishing them from various mimics, and underscores the importance of imaging modalities such as CT, MRI, PET/CT, and PET/MRI in effective decision-making and management.

Tumor markers are used routinely for surveillance in patients treated for colorectal cancer (CRC). However, the prognostic implications of elevated preoperative tumor markers in patients treated for CRC and peritoneal metastases (PM) has not been well defined. The utility of carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9) and cancer antigen 125 (CA125) to predict outcome for these patients is reported.

Clinical and histologic features plus preoperative tumor markers were recorded within 1 week prior to CRS. Impact on overall survival of these factors was analyzed by univariate and multivariate analysis.

Two hundred and four patients were in our database and 140 patients (75.3 %) had at least a single elevated preoperative tumor marker. In an analysis of clinical and histologic parameters preoperatively, a poorly differentiated tumor, signet ring morphology, a peritoneal cancer index (PCI) of ≥16 and an incomplete cytoreduction had a negative impact on median survival. In a multivariate analysis of clinical and histologic features together with tumor markers, an elevated CA19-9 and CA125 was independently associated with reduced overall survival (HR 2.7, p < 0.0001 and HR 2.2, p = 0.005), respectively. Quantitative assessment of CEA (HR 0.5, p = 0.0094) and CA19-9 (HR 4.9, p < 0.001) greater than x10 ULN showed reduced survival.

Preoperative assessment of symptoms and histopathology, PCI and a complete CRS combined with tumor markers CEA, CA19-9 and CA125 are independent prognostic indicators for selection by the multidisciplinary team of CRC PM patients for CRS and HIPEC. All three tumor markers are needed for a meaningful assessment.

Acute kidney injury after CRS + HIPEC is a serious postoperative complication, but only a few studies have reported its postoperative risk factors. In addition, there are large discrepancies in the results of available observational studies.

We searched The Cochrane Library, Embase, Web of Science,and PubMed to identify observational studies reporting risk factors for AKI after CRS + HIPEC. A meta-analysis was performed to investigate the effect of various preoperative and intraoperative risk factors on AKI after CRS + HIPEC.

A total of 7 studies were included in this study, comprising 1550 patients who developed AKI after CRS + HIPEC. The results of meta-analysis showed that the significant preoperative risk factors were age, sex, BMI, eGFR, Hb, PCI, diabetes mellitus, and hypertension. IO cisplatin, IO SBP < 100 was identified as an intraoperative risk factor, whereas IO mitomycin emerged as a protective factor for postoperative AKI. In addition, the risk of postoperative AKI varied by primary tumor site, with Appendix being less prone to AKI, while mesothelioma and ovarian, two sites with a greatly elevated risk of postoperative AKI.

This meta-analysis identified a number of risk factors for postoperative AKI after CRS + HIPEC. By identifying these risk factors, it is more beneficial for clinicians to perform early preoperative interventions and select the most appropriate treatment strategy for their patients, thus minimizing the risk of postoperative AKI.

PROSPERO CRD42024585269.

Patients diagnosed with pseudomyxoma peritonei (PMP) of appendiceal origin typically present with high tumor burden and require extensive cytoreductive surgery (CRS) to achieve optimal cytoreduction. This study describes an en bloc "rolled-up carpet" surgical technique for total parietal peritonectomy and multivisceral resection while also analyzing the perioperative and tumor outcomes of this technique.

The study reviewed the data of 7 patients underwent en bloc "rolled-up carpet" extensive CRS between August 2020 and April 2023. Perioperative and tumor outcomes were analyzed.

Seven patients underwent extensive treatment involving total peritoneal and multivisceral resection. Complete cytoreduction was successfully achieved in all patients. Six patients (85.7 %) successfully completed hyperthermic intraperitoneal chemotherapy (HIPEC). Three patients (42.9 %) had low-grade mucinous appendiceal neoplasm, while the remaining four patients (57.1 %) had high-grade. Two patients (28.6 %) experienced major morbidity, which was successfully treated, and they were discharged. There were no secondary surgery and no surgery-related mortality. During a median follow-up of 25 months (range, 12-46 months), no patient experienced recurrence. After 12 months postoperatively, the quality of life (QOL) of the 7 patients was assessed using the EORTC QLQ-C30, revealing scores similar to the reference values of the EORTC general population (p > 0.05).

En bloc "rolled-up carpet" extensive cytoreductive surgery is a feasible and safe technique for the treatment of appendiceal PMP with high tumor burden. This technique achieved complete cytoreduction with acceptable blood loss volume, operative time, and major morbidity. In short-term follow-up, no recurrence was noted, with patients having a satisfactory QOL.

Patients with gastric cancer peritoneal metastases (GCPM) have Stage IV disease. Systemic therapy is a crucial aspect of their care. Patients with GCPM should have their tumors tested for HER2 and PD-L1 expression and microsatellite instability for potential targeted therapies. If patients with synchronous GCPM have stable disease following neoadjuvant therapy, surgical intervention can be considered. Patients with positive cytology or low-volume peritoneal disease (peritoneal carcinomatosis index [PCI] < 7) may "convert" to negative cytology or resolution of peritoneal metastases following intraperitoneal therapy and may be candidates for subsequent gastrectomy.

disease burden (PCI), completeness of cytoreduction or histological features, are known to influence survival after CRS-HIPEC for colorectal peritoneal metastases (CPM). However, there is still debate about influence of CPM onset. The aim of this study is to determine the impact of CPM onset on oncological outcomes after CRS-HIPEC.

all patients with CPM scheduled for CRS-HIPEC at one reference center between December 2007 and September 2022 were included. s-PM were defined as those diagnosed at primary disease treatment; m-PM were considered those diagnosed during follow-up. Survival outcomes and recurrence rates were compared using a pragmatic analysis.

125 patients with s-CPM and 170 patients with m-CPM were analyzed. Median follow-up was 58.6 and 50.6 months in s-CPM and m-CPM groups(p = 0.11). Complete cytoreduction (CCS-0/-1) rates were comparable: 84 % s-CPM vs. 88.2 % m-CPM(p = 0.190). Overall survival (OS) was significantly shorter in s-CPM: 24.7 vs. 46.6 months (p = 0.024). Conversely, median disease-free survival was similar in both groups, 10 months vs. 11 months(p = 0.155). Patients in the s-CPM group presented more pN+(p = 0.001), higher histologic grade(p = 0.007) and PCI(p = 0.04), and higher rate of concurrent liver metastases(p = 0.004). RAS/BRAF gene mutations and microsatellite instability did not differ significantly. Perioperative chemotherapy regimens and tolerance were also similar.

despite s-CPM being associated with impaired OS after CRS-HIPEC, the onset of PM was not found to be an independent determinant for survival. High-risk molecular and histological features strongly influence oncological outcomes after CRS-HIPEC. This is valuable data that could aid in preoperative patient selection process for CRS-HIPEC.