Background/Objectives: Primary cutaneous lymphomas (CLs) are a group of skin-limited lymphoproliferative disorders, including cutaneous T-cell (CTCLs) and B-cell lymphomas (CBCLs). Photodynamic therapy (PDT), a non-invasive, light-activated treatment, has gained attention as a skin-directed therapy for early-stage CLs due to its selectivity and favorable safety profile. This systematic review evaluates the current evidence on the clinical use of PDT in managing CLs. Methods: A systematic literature search was conducted in PubMed, Scopus, and Embase through 1 September 2024 following PRISMA guidelines. Search terms included "primary cutaneous skin lymphoma", "CTCL", "CBCL", "mycosis fungoides", "lymphomatoid papulosis", and "photodynamic therapy". After screening 1033 records, 30 studies were included. Data were extracted and categorized by lymphoma subtype and clinical outcomes. Results: Of the included studies, 23 focused on mycosis fungoides (MF), 5 on lymphomatoid papulosis (LyP), and 2 on CBCL. PDT demonstrated notable clinical efficacy in early-stage and localized disease, particularly MF, using methyl aminolevulinate (MAL) or 5-aminolevulinic acid (5-ALA) as photosensitizers. Adjunctive techniques like microneedling and laser-assisted delivery improved treatment outcomes. PDT was generally well tolerated, with mild, transient side effects; rare complications such as localized neuropathy were reported. Conclusions: PDT is a promising, non-invasive treatment for early-stage CLs, especially MF and indolent CBCL variants. While current evidence supports its safety and effectiveness, further comparative and prospective studies are needed to refine protocols, evaluate long-term efficacy, and compare different photosensitizers.

Despite remarkable advances in the core modalities used in combating cancer, malignant diseases remain the second largest cause of death globally. Interstitial photodynamic therapy (IPDT) has emerged as an alternative approach for the treatment of solid tumors.

The aim of our study is to outline the advancements in IPDT in recent years and provide our vision for the inclusion of IPDT in standard-of-care (SoC) treatment guidelines of specific malignant diseases.

First, the SoC treatment for solid tumors is described, and the attractive properties of IPDT are presented. Second, the application of IPDT for selected types of tumors is discussed. Finally, future opportunities are considered.

Strong research efforts in academic, clinical, and industrial settings have led to significant improvements in the current implementation of IPDT, and these studies have demonstrated the unique advantages of this modality for the treatment of solid tumors. It is envisioned that further randomized prospective clinical trials and treatment optimization will enable a wide acceptance of IPDT in the clinical community and inclusion in SoC guidelines for well-defined clinical indications.

The minimally invasive nature of this treatment modality combined with the relatively mild side effects makes IPDT a compelling alternative option for treatment in a number of clinical applications. The adaptability of this technique provides many opportunities to both optimize and personalize the treatment.

The delta-amino acid 5-aminolevulinic acid (ALA), is the precursor of the endogenous photosensitiser Protoporphyrin IX (PpIX), and is currently approved for Photodynamic Therapy (PDT) of certain superficial cancers. However, ALA-PDT is not very effective in diseases in which T-cells play a significant role. Cutaneous T-cell lymphomas (CTCL) is a group of non-Hodgkin malignant diseases, which includes mycosis fungoides (MF) and Sézary syndrome (SS). In previous work, we have designed new ALA esters synthesised by three-component Passerini reactions, and some of them showed higher performance as compared to ALA. This work aimed to determine the efficacy as pro-photosensitisers of five new ALA esters of 2-hydroxy-N-arylacetamides (1f, 1 g, 1 h, 1i and 1 k) of higher lipophilicity than ALA in Myla cells of MF and HuT-78 cells of SS. We have also tested its effectiveness against ALA and the already marketed ALA methyl ester (Me-ALA) and ALA hexyl ester (He-ALA). Both cell Myla and SS cells were effectively and equally photoinactivated by ALA-PDT. Besides, the concentration of ALA required to induce half the maximal porphyrin synthesis was 209 μM for Myla and 169 μM for HuT-78 cells. As a criterion of efficacy, we calculated the concentration of the ALA derivatives necessary to induce half the plateau porphyrin values obtained from ALA. These values were achieved at concentrations 4 and 12 times lower compared to ALA, according to the derivative used. For He-ALA, concentrations were 24 to 25 times lower than required for ALA for inducing comparable porphyrin synthesis in both CTCL cells. The light doses for inducing 50% of cell death (LD50) for He-ALA, 1f, 1 g, 1 h and 1i were around 18 and 25 J/cm² for Myla and HuT-78 cells respectively, after exposure to 0.05 mM concentrations of the compounds. On the other hand, the LD50s for the compound 1 k were 40 and 57 J/cm² for Myla and HuT-78, respectively. In contrast, 0.05 mM of ALA and Me-ALA did not provoke photokilling since the concentration employed was far below the porphyrin saturation point for these compounds. Our results suggest the potential use of ALA derivatives for topical application in PDT treatment of MF and extracorporeal PDT for the depletion of activated T-cells in SS.

The goal of this study is a comparative analysis of the efficiency of the PDT protocols for CT26 tumor model treatment in Balb/c mice employing red and blue light with both topical and intravenous administration of chlorin-based photosensitizers (PSs). The considered protocols include the doses of 250 J/cm² delivered at 660 nm, 200 J/cm² delivered at 405 nm, and 250 J/cm² delivered at both wavelengths with equal energy density contribution. Dual-wavelength fluorescence imaging was employed to estimate both photobleaching efficiency, typical photobleaching rates and the procedure impact depth, while optical coherence tomography with angiography modality (OCT-A) was employed to monitor the tumor vasculature response for up to 7 days after the procedure with subsequent histology inspection. Red light or dual-wavelength PDT regimes with intravenous PS injection were demonstrated to provide the most pronounced tumor response among all the considered cases. On the contrary, blue light regimes were demonstrated to be most efficient among topical application and irradiation only regimes. Tumor size dynamics for different groups is in good agreement with the tumor response predictions based on OCT-A taken in 24h after exposure and the results of histology analysis performed in 7 days after the exposure.

In addition to approved indications in non-melanoma skin cancer in immunocompetent patients, topical photodynamic therapy (PDT) has also been studied for its place in the treatment of, as well as its potential to prevent, superficial skin cancers in immune-suppressed patients, although sustained clearance rates are lower than for immune-competent individuals. PDT using a nanoemulsion of ALA in a daylight or conventional PDT protocol has been approved for use in field cancerization, although evidence of the potential of the treatment to prevent new SCC remained limited. High-quality evidence supports a strong recommendation for the use of topical PDT in photorejuvenation as well as for acne, refractory warts, cutaneous leishmaniasis and in onychomycosis, although these indications currently lack approvals for use and protocols remain to be optimized, with more comparative evidence with established therapies required to establish its place in practice. Adverse events across all indications for PDT can be minimized through the use of modified and low-irradiance regimens, with a low risk of contact allergy to photosensitizer prodrugs, and no other significant documented longer-term risks with no current evidence of cumulative toxicity or photocarcinogenic risk. The literature on the pharmacoeconomics for using PDT is also reviewed, although accurate comparisons are difficult to establish in different healthcare settings, comparing hospital/office-based therapies of PDT and surgery with topical ointments, requiring inclusion of number of visits, real-world efficacy as well as considering the value to be placed on cosmetic outcome and patient preference. This guideline, published over two parts, considers all current approved and emerging indications for the use of topical photodynamic therapy in Dermatology prepared by the PDT subgroup of the European Dermatology Forum guidelines committee. It presents consensual expert recommendations reflecting current published evidence.

After studying this article, the participant should be able to: 1. Characterize basal and squamous cell carcinomas as low or high risk based on size, location, histology, and clinical features. 2. Understand appropriate surgical margins in low- and high-risk lesions, and other management options, including Mohs micrographic surgery, electrodissection and curettage, topical agents, cryotherapy, photodynamic therapy, and radiation therapy. 3. Discuss adjuvant therapies for locally advanced and metastatic disease, including radiation therapy, chemotherapy, and targeted therapies such as hedgehog pathway inhibitors. 4. Educate patients on preventive measures such as skin examinations, sun protection, oral retinoids, and oral nicotinamide (vitamin B3). 5. Devise a reconstructive plan once clear oncologic margins are obtained.

With the growing incidence of basal and squamous cell carcinoma, there is an increasing demand for appropriate oncologic management and aesthetic reconstruction. The goal of this CME article is to provide a foundation of knowledge to accurately diagnose, stage, and treat nonmelanoma skin cancers. In addition, it provides the practicing plastic surgeon alternate tools for managing these skin lesions, including topical agents, destructive therapies, and radiation therapy. Lastly, reconstructive plans for selected soft-tissue defects are discussed.

The prognosis of patients suffering from malignant cutaneous neoplasms can be improved by early diagnosis. Exact demarcation of tumor margins could contribute to optimum results in surgical excision and reconstruction. The purpose of our study is to evaluate Photofrin^® with a new diagnostic procedure, photodynamic diagnosis (PDD), for the detection of Bowen's disease (squamous cell carcinoma (SCC) in situ), SCC, and basal cell carcinoma (BCC).

Sixty patients with cutaneous neoplasms received 2.5 mg/mL Photofrin^® solution topically. After a period of 3 hours, the patients underwent fluorescence illumination (λex = 370-450 nm). Guided by their visible fluorescence, lesions were biopsied at four suspicious sites in each patient. All specimens were analyzed and measured by a pathologist. A quantitative analysis of the fluorescence contrast between the neoplasms and healthy tissue was performed using the Red, Blue, and Green (RGB) Mode and Gray Scale (GS). Statistical analysis was performed by the analysis of variance (ANOVA) test for multiple comparisons.

Of the 60 patients (20 Bowen's disease, 20 SCC, and 20 BCC), malignant neoplasms could be clearly distinguished from adjacent healthy tissue under fluorescence illumination (P < 0.0001). The sensitivity of the malignant neoplasms evaluated using the RGB and GS modes combined showed 92.74% in image results. The specificity of the malignant neoplasms evaluated using the RGB and GS modes combined showed 95.77%.

Light-induced fluorescence detection using topical Photofrin^® provides a sensitive, noninvasive technique for the early identification of malignant cutaneous neoplasms.

Mycosis fungoides is the most common cutaneous T-cell lymphoma. It is characterized by slow progress over years to decades, developing from patches to infiltrated plaques, and sometimes to tumors. Therapies such as localized chemotherapy, photochemotherapy and radiotherapy are often employed when lesions of refractory or relapsing mycosis fungoides are resistant to conventional therapies. However, these methods have acute or chronic side effects and toxicity, which may accumulate with repeated and protracted treatment cycles. Photodynamic therapy is a promising, well-tolerated option for the treatment of localized lesions with excellent cosmetic outcomes. In this article, we systematically reviewed and discussed clinical application of photodynamic therapy in relapsed or refractory mycosis fungoides. There are 20 papers included in this review article.

Photodynamic therapy (PDT) is a clinical modality of photochemotherapy based on the accumulation of a photosensitizer in target cells and subsequent irradiation of the tissue with light of adequate wavelength promoting reactive oxygen species (ROS) formation and cell death. PDT is used in several medical specialties as an organ-specific therapy for different entities. In this review we focus on the current dermatological procedure of PDT. In the most widely used PDT protocol in dermatology, ROS production occurs by accumulation of the endogenous photosensitizer protoporphyrin IX after treatment with the metabolic precursors 5-methylaminolevulinic acid (MAL) or 5-aminolevulinic acid (ALA). To date, current approved dermatological indications of PDT include actinic keratoses (AK), basal cell carcinoma (BCC) and in situ squamous cell carcinoma (SCC) also known as Bowen disease (BD). With regards to AKs, PDT can also treat the cancerization field carrying an oncogenic risk. In addition, an increasing number of pathologies, such as other skin cancers, infectious, inflammatory or pilosebaceous diseases are being considered as potentially treatable entities with PDT. Besides the known therapeutic properties of PDT, there is a modality used for skin rejuvenation and aesthetic purposes defined as photodynamic photorejuvenation. This technique enables the remodelling of collagen, which in turn prevents and treats photoaging stygmata. Finally we explore a new potential treatment field for PDT determined by the activation of follicular bulge stem cells caused by in situ ROS formation.

Laser spectroscopy provides many possibilities for multi-disciplinary applications in environmental monitoring, in the ecological field, for food safety investigations, and in biomedicine. The paper gives several examples of the power of multi-disciplinary applications of laser spectroscopy as pursued in our research group. The studies utilize mostly similar and widely applicable spectroscopic approaches. Air pollution and vegetation monitoring by lidar techniques, as well as agricultural pest insect monitoring and classification by elastic scattering and fluorescence spectroscopy are described. Biomedical aspects include food safety applications and medical diagnostics of sinusitis and otitis, with strong connection to the abatement of antibiotics resistance development.

5-Aminolevulinic acid (ALA) is a widely used photodynamic therapy (PDT) prodrug in the clinic. It can be metalized to the photosensitizer PpIX, which produces toxic singlet oxygen to kill cancer cells upon visible light irradiation. Herein, a core/shell-structured vehicle is designed to comprise magnetite colloidal supraparticles (MCSPs) as cores and ALA-Zn(II) coordination polymers as shells (Fe3O4@ALA-Zn(II) ) for target pro-photosensitizer delivery. The coordination polymers with 2D layered structures are locally deposited on the MCSPs by the complexation of the ALA and Zn(II) ions, and are readily controlled by varying the feed precursors and reaction temperatures. The maximum conjugated ALA amount is up to 17%. The Fe3O4@ALA-Zn(II) microspheres exhibit pH-sensitive release of ALA in acidic environment and rapid magnetic responsiveness. Cytotoxicity results demonstrate that Fe3O4@ALA-Zn(II) shows a significant inhibitory effect to T24 cells and is nontoxic to 293T normal cells as exposed to the 630 nm visible light for a very short time, which may due to the selective accumulation of ALA-induced PpIX in T24 cancer cells. Compared to the ALA used alone, the coordination polymer form is more efficient because of the bioactivity of incorporated Zn ions despite underlying the same apoptosis mechanism as ALA agent.

Photodynamic therapy (PDT) is used for skin treatments of premalignant and cancer lesions and recognized as a non-invasive technique that combines tissue photosensitization and subsequent exposure to light to induce cell death. However, it is limited to the treatment of superficial lesions, mainly due to the low cream penetration. Therefore, the improvement of transdermal distribution of aminolevulinic acid (ALA) is needed. In this study, the kinetics and homogeneity of production of ALA-induced PpIX after the skin pre-treatment with microneedles rollers of 0.5, 1.0 and 1.5 mm length were investigated. An improvement in homogeneity and production of PpIX was shown in a porcine model. Widefield fluorescence imaging three hours after the topical application of ALA-cream in the combined treatment with microeedles rollers.

Skin cancer is the most common cancer worldwide, and its incidence rate in South Africa is increasing. Photodynamic therapy (PDT) has been shown to be an effective treatment modality, through topical administration, for treatment of non-melanoma skin cancers. Our group investigates hypericin-induced PDT (HYP-PDT) for the treatment of both non-melanoma and melanoma skin cancers. However, a prerequisite for effective cancer treatments is efficient and selective targeting of the tumoral cells with minimal collateral damage to the surrounding normal cells, as it is well established that cancer therapies have bystander effects on normal cells in the body, often causing undesirable side effects. The aim of this study was to investigate the cellular and molecular effects of HYP-PDT on normal primary human keratinocytes (Kc), melanocytes (Mc) and fibroblasts (Fb) in an in vitro tissue culture model which represented both the epidermal and dermal cellular compartments of human skin. Cell viability analysis revealed a differential cytotoxic response to a range of HYP-PDT doses in all the human skin cell types, showing that Fb (LD50=1.75μM) were the most susceptible to HYP-PDT, followed by Mc (LD50=3.5μM) and Kc (LD50>4μM HYP-PDT) These results correlated with the morphological analysis which displayed distinct morphological changes in Fb and Mc, 24h post treatment with non-lethal (1μM) and lethal (3μM) doses of HYP-PDT, but the highest HYP-PDT doses had no effect on Kc morphology. Fluorescent microscopy displayed cytoplasmic localization of HYP in all the 3 skin cell types and additionally, HYP was excluded from the nuclei in all the cell types. Intracellular ROS levels measured in Fb at 3μM HYP-PDT, displayed a significant 3.8 fold (p<0.05) increase in ROS, but no significant difference in ROS levels occurred in Mc or Kc. Furthermore, 64% (p<0.005) early apoptotic Fb and 20% (p<0.05) early apoptotic Mc were evident; using fluorescence activated cell sorting (FACS), 24h post 3μM HYP-PDT. These results depict a differential response to HYP-PDT by different human skin cells thus highlighting the efficacy and indeed, the potential bystander effect of if administered in vivo. This study contributes toward our knowledge of the cellular response of the epidermis to photodynamic therapies and will possibly enhance the efficacy of future photobiological treatments.

Bowen's disease is a squamous cell carcinoma in situ and has the potential to progress to a squamous cell carcinoma. The authors treated two female patients (a 39-year-old and a 41-year-old) with Bowen's disease in the vulva area using topical photodynamic therapy (PDT), involving the use of 5-aminolaevulinic acid and a light-emitting diode device. The light was administered at an intensity of 80 mW/cm(2) for a dose of 120 J/cm(2) biweekly for 6 cycles. The 39-year-old patient showed excellent clinical improvement, but the other patient achieved only a partial response. Even though one patient underwent a total excision 1 year later due to recurrence, both patients were satisfied with the cosmetic outcomes of this therapy and the partial improvement over time. The common side effect of PDT was a stinging sensation. PDT provides a relatively effective and useful alternative treatment for Bowen's disease in the vulva area.

Photodynamic therapy is a treatment modality that is developing rapidly and increasing in utilization within various medical specialties, including dermatology. This technique requires the presence of a photosensitizer, light energy and molecular oxygen to selectively destroy pathologic cells. A thorough understanding of photobiology and tissue optics is necessary to correctly and effectively utilize photodynamic therapy in dermatology. Photodynamic therapy has been approved by the US Food and Drug Administration to treat actinic keratoses. In Europe, photodynamic therapy is currently being used in the treatment of actinic keratoses and basal cell carcinoma. Other off-label uses of photodynamic therapy have included cutaneous lesions of Bowen's disease, psoriasis, cutaneous T-cell lymphoma and acne. Most recently, photodynamic therapy has been employed in photorejuvenation. The advantages of photodynamic therapy include the capacity for noninvasive targeted therapy via topical application of the drug and local irradiation of involved areas, as well as the ability to generate excellent cosmetic results with minimal discomfort. This review summarizes the fundamentals of photodynamic therapy and its role in the treatment of cutaneous disorders, particularly skin malignancies.

Publications reporting photodynamic therapy (PDT) in mycosis fungoides (MF) are rare, involve small samples, and are difficult to compare because of a lack of technical standardization.

We sought to assess PDT effectiveness and tolerability in early-stage MF using a strict reproducible procedure.

This was a prospective study conducted in Nantes University Hospital, France, including patients older than 18 years with histologically proven MF (stage IA or IB). Methyl-aminolevulinic acid-PDT sessions were repeated monthly for 6 months. Clinical and histologic responses were assessed 1 month after the last session. Patient satisfaction was assessed by telephone survey.

Twelve patients (with 29 lesions) were treated with PDT. An objective response in target lesions was obtained in 75% of patients. Response rates were similar between plaques and patches but higher in sun-protected compared with sun-exposed areas (trend without reaching significance). During PDT, new lesions appeared in 5 of 12 patients in untreated areas. Most patients were highly satisfied and preferred PDT to the topical chemotherapy previously used.

PDT procedure criteria selection was partially arbitrary.

In early-stage MF, PDT is effective and appreciated (especially when compared with conventional topical chemotherapy). Unilesional and paucilesional forms and lesions in sun-protected areas are to be preferred.

Photodynamic therapy involves the topical application of a photosensitizer to a lesion, which is then subsequently exposed to a light source. It is mainly used in the nonsurgical treatment of nonmelanoma skin cancer, in which it achieves good response and an excellent cosmetic result. In the last 10 years, photodynamic therapy has also been used with some success in the treatment of plaque-stage mycosis fungoides and has emerged as an alternative to skin-directed therapies. Its main advantages are the good response to treatment, lack of toxicity, and excellent cosmetic results. This article reviews the literature and the practical application of photodynamic therapy in mycosis fungoides.

Mycosis fungoides is a candidate for skin-directed therapies in its initial stages. In recent years, therapeutic options outside of the normal treatment recommendations such as topical imiquimod, topical tazarotene, topical methotrexate, excimer light sources, and photodynamic therapy have been published with variable results. These alternatives have been useful in cases of localized mycosis fungoides that do not respond to routine treatments; nevertheless, more studies on these methods are still needed. This article summarizes the literature and data that are known so far about these treatments.

Photodynamic therapy (PDT) using topical aminolevulinic acid (ALA) depends on local drug uptake, metabolism to porphyrins, and depth of light penetration using different wavelengths. Topical ALA-PDT has limited depth of drug penetration. We studied induced porphyrin distribution and PDT after intradermal ALA administration using different drug concentrations followed by high-fluence red light irradiation.

Intradermal injections (∼2 mm deep) of ALA concentrations from 0.0005% to 1% were studied in swine to evaluated porphyrin fluorescence before PDT and clinical and histological damage 24 hours after PDT. Porphyrin accumulation was measured by fluorescence microscopy of frozen section. PDT was performed 3 hours after intradermal injections using a 635 nm LED array at a fluence of 200 J/cm2 . Skin responses to PDT were observed grossly and by histology (blind evaluation).

Intradermal ALA caused porphyrin accumulation in epidermis, hair follicles (HF), sebaceous glands (SG), sweat glands (eccrine glands, EG and apocrine glands, AG), and subcutaneous fat. Significant differences of fluorescence intensity were observed between different skin structures (P < 0.05), but there was no significant difference comparing HF to SG; epidermis with either HF or SG; and dermis with fat (P > 0.05). Intradermal ALA is potent. ALA concentrations ≥0.25% followed by red light exposures caused a very intense vascular PDT reaction. Moderate doses of injected ALA concentration (∼0.06%), selectively targeted EG. Low doses (≤0.016%) targeted fat; producing fat necrosis with minimal inflammation, manifested both clinically and histologically. In contrast to topical ALA-PDT, intradermal ALA-PDT can effectively photosensitize deep skin structures.

Potentially, intradermal ALA-PDT using various ALA concentrations may be useful for treating vascular lesions (malformations, hemangiomas, tumors), EG/AG disorders, fat or deep targets in skin.

This study was undertaken to evaluate the effects of indocyanine green as a sensitizer in both photodynamic and radiation therapy on MCF-7 human breast cancer cells line. The cells were incubated with indocyanine green at different concentrations for 24h and were then exposed in the independent treatment groups to a non-coherent light at different fluence rates and X-ray ionizing radiation at different dose rates. In addition, combination effects of this chemo, photo, and radiotherapy were evaluated. The percentage of the cell survival was investigated using the MTT assay. The results showed that indocyanine green had no significant cytotoxic effects up to 100 μM but as a photosensitizer had a strong cytotoxic effect on cancer cells. Despite, indocyanine green could not act as a radiosensitizer. Furthermore, it is surprising to find that 50 μM of indocyanine green in combination with light at 60 J/cm(2) and 4 Gy of X-ray radiation astonishingly killed cancer cells and reduced the percentage of viable cancer cells to be 3.42%. According to the findings, we observed the same efficacy of treatment by adding a low dose of radiation and reducing light fluence rate. In fact, it appears from our data that the adverse effects of photodynamic therapy can be partially abated without reducing the efficacy of treatment. Obviously, this new therapeutic avenue in breast cancer therapy could be worth further investigation and elucidation and should be tested in vivo models for being applied in human therapy.

The diagnosis and management of periocular cutaneous malignancies are essential components of an ophthalmologist's practice. Skin cancers comprise nearly one-third of newly diagnosed malignancies. Furthermore, the incidence of skin cancer appears to be increasing. Multiple treatment modalities exist for periocular cutaneous malignancy. Surgical extirpation, often with the combined expertise of a Mohs micrographic surgeon, is typically the first line therapy and is often curative in the periocular region, depending on a variety of factors, including tumour histology, specific location, depth of invasion and surgical technique. However, there are instances where a less invasive, non-surgical treatment option is warranted, including patients who are poor surgical risks or those with diffuse disease. The purpose of this article is to review the literature and describe the non-surgical treatment options, indications and efficacies for non-melanoma primary eyelid malignancies.

Photodynamic therapy (PDT) using topical 5-aminolevulinic acid (ALA) is currently used as a clinical treatment for nonmelanoma skin cancers. In order to optimize PDT treatment, vascular disruption early in treatment must be identified and prevented. We present blood flow responses to topical ALA-PDT in a preclinical model and basal cell carcinoma patients assessed by diffuse correlation spectroscopy (DCS). Our results show that ALA-PDT induced early blood flow changes and these changes were irradiance dependent. It is clear that there exists considerable variation in the blood flow responses in patients from lesion to lesion. Monitoring blood flow parameter may be useful for assessing ALA-PDT response and planning.

Photodynamic therapy (PDT) with topical 5-aminolevulinic acid (ALA) is reported to be an effective and safe treatment for superficial non-melanoma skin cancers. We have developed an photodynamic therapy with topical delta-aminolevulinic acid (ALA-PDT) protocol using intense pulsed light (IPL) for treating Bowen's disease (BD). Three patients diagnosed with BD by skin biopsy were recruited in this study. They received IPL treatment after 3 h of occlusive dressing with application of ALA. This protocol was repeated every 2 weeks for a total of five sessions. The treated areas did not show any signs of BD for more than 1 year; therefore, it appeared that the affected areas showed improvement in all the patients. No patients withdrew from the study because of side-effects. ALA-PDT with IPL as a light source is well tolerated by patients and is beneficial for treating BD.

Photodynamic therapy (PDT) is reviewed using the treatment of skin tumors as an example of superficial lesions and prostate cancer as an example of deep-lying lesions requiring interstitial intervention. These two applications are among the most commonly studied in oncological PDT, and illustrate well the different challenges facing the two modalities of PDT-superficial and interstitial. They thus serve as good examples to illustrate the entire field of PDT in oncology. PDT is discussed based on the Lund University group's over 20 yr of experience in the field. In particular, the interplay between optical diagnostics and dosimetry and the delivery of the therapeutic light dose are highlighted. An interactive multiple-fiber interstitial procedure to deliver the required therapeutic dose based on the assessment of light fluence rate and sensitizer concentration and oxygen level throughout the tumor is presented.

Cutaneous T-cell lymphoma is a malignancy of skin-homing T cells. This unique population of lymphocytes requires alternative therapies to those used in nodal lymphomas. Although phototherapy and nitrogen mustard have been standard treatments for decades, newer therapies have been arriving with increased frequency. Moreover, some therapies, currently used to treat other diseases, have been used with good effect. These innovative therapies are discussed, with review of current data and examples of how these therapies may be used today.