Meta-Analysis
Copyright ©The Author(s) 2021.
World J Gastrointest Oncol. Jan 15, 2021; 13(1): 69-86
Published online Jan 15, 2021. doi: 10.4251/wjgo.v13.i1.69
Table 1 Baseline characteristics of the included studies
Ref.
Year
Location
Time frame
Type
Patients, n IORT/ non-IORT
Age in yr, mean IORT non-IORT
Follow-up in mo, mean IORT non-IORT
Resection margin
Clinical stages, %
PR-RT, %
CT, %
PO-RT, %
IORT dose in Gy mean
NOS score
Willett et al[23]1991United States1978-1988Observational studies20; 21/22; 264 v26 vR0; R1/R2NA100NA0157
Suzuki et al[24]1995Germany1981-1988Observational studies42/6464.3 v44 vR1/R2NANANA98208
Huber et al[25]1996Germany1989-1993Observational studies36/18NA25.5 vR0/R1/R2T3 (50); T4 (50)5010050158
Wiig et al[26]2002Norway1990-1999Observational studies59/48NANAR0/R1/R2NA100NANA15-208
Ratto et al[27]2003Italy1990-1997Observational studies19/246274 vNAT3 (7); T4 (93)NANANA10-157
Sadahiro et al[28]2004Japan1991-2001Observational studies99/6860 6167 vNAT1/T2 (29); T3 (59); T4 (12)10053017.37
Ferenschild et al[29]2006Netherlands1987-2001Observational studies30/9366 v25 vR0T2 (14); T3 (57); T4 (25)100NA0109
Masaki et al[30]2008Japan2000-2007RCT19/22NA34 vNAT1/T2 (11); T3 (89)NA37NA18-20 fRCT
Valentini et al[31]2009Italy1991-2006Observational studies11/3562 v80 vR0T4 (100)NANANA10-15 f7
Dubois et al[32]2011France1993-2001RCT72/6862.5 64.560 vNAT3/T4 (100)10025NA18RCT
Zhang et al[35]2014China1996-2007Observational studies45/4661 6172.9 vNAT3 (100)NA10051208
Alberda et al[33]2014Netherlands1996-2012Observational studies21; 22/31; 1766 59/61 5638 39/23 12R0/R1T3 (41); T4 (59)NANANA108
Klink et al[34]2014Germany2004-2012Observational studies52/11162 63NAR0T3/T4 (100)NANANA10-20 f9
Zhang et al[36]2015China1994-2007Observational studies71/7758 6372.3 vR0/R1/R2T2 (6); T3 (52); T4 (42)NA100100157
Masaki et al[19]2020Japan2000-2017RCT38/38NA72 vR0/R1T1/T2 (17); T3 (80); T4 (3)NANANA18-20 fRCT
Table 2 Outcome indicators of the included studies
Ref. %       
Surgery, %       
Resection margin %       
5-yr OS, % IORT non-IORT %       
5-yr DFS, % IORT non-IORT %       
5-yr LC, % IORT non-IORT %       
Complications, % IORT non-IORT
Willett et al[23]NAR0; R1/R2NA53 60; 32 NA88 71; 60 0Abscess (5); Fistulae (7) Wound (5); Anastomotic leakage (2) Ureteric obstruction (2) Sacral necrosis (2)NA
Suzuki et al[24]LAR (57); APR (35); Hartmann (6)R1/R219 7.330 5.960 7Pelvic abscess (12) Fistula (2) Perineal wound (7); Small bowel obstruction (14) Ureteral obstruction (7)Pelvic abscess (11) Fistula (6) Perineal wound (2); Small bowel obstruction (5) Ureteral obstruction (2)
Huber et al[25]LAR (84); APR (16)R0/R1/R240 2028 NA80 24Wound (45) Sacral wound dehiscence (21); Neurogenic bladder dysfunction (8)Wound (58) Sacral wound dehiscence (26); Neurogenic bladder dysfunction (11)
Wiig et al[26]LAR (31); APR (10); Hartmann (19)R0/R1/R230 35NA44 28Abscess (24) wound (3) Anastomotic leakage (3); Late perineal healing (10)Abscess (29) wound (13) Anastomotic leakage (13); Late perineal healing (2)
Ratto et al[27]LAR (33); APR (56)NANA47 3991 57NA
Sadahiro et al[28]LAR (54); APR (46)NA79 5871 5498 84Anastomotic leakage (6) Wound (23) Bleeding (3) Neurogenic bladder dysfunction (2)Anastomotic leakage (3) Wound (12) Bleeding (1) Neurogenic bladder dysfunction (4)
Ferenschild et al[29]NAR056 66NA71 72NA
Masaki et al[30]TME (100)NA64 NA60 NA95 95Anastomotic breakdown (25) Intrapelvic abscess (14)Anastomotic breakdown (14) Intrapelvic abscess (21)
Valentini et al[31]APR (56)R019.4 16.341.1 16.879.5 23.7NA
Dubois et al[32]APR (20)NA77 7562 6692 93Anastomotic leakage (8.5) Re-operation (11.3) Infectious complications (9.9) Medical complications (7.0) Sacral necrosis (1.5)Anastomotic leakage (4.4) Re-operation (8.8) Infectious complications (11.8) Medical complications (2.9)
Zhang et al[35]TME (80)NA84 8671 7384 86Grade 3 diarrhea (3) numbness and motor weakness (4.4)Leukopenia (10.9) Grade 3 diarrhea (14) incomplete intestinal obstruction (6.5) acute mucositis of the anal verge (23.9)
Alberda et al[33]TME (100)R0; R163 81; 41 13NA70 79; 84 41Abdominal/perineal wound infections (31) abscess (6) Anastomotic leakage (2) Urinary tract infection (8) Cardiac (6)Abdominal/perineal wound infection (23) abscess (13) Anastomotic leakage (3) Urinary tract infection (8) Cardiac (3)
Klink et al[32]NAR0NANANAPostoperative bleeding (0) Anastomotic leakage (11) Surgical site infection (15) Abscess (10) Fistula (2) Stenosis (4) Bladder dysfunction (8) Urethral leakage (0) Sexual dysfunction (2)Postoperative bleeding (4) Anastomotic leakage (14) Surgical site infection (9) Abscess (5) Fistula (0) Stenosis (1) Bladder dysfunction (10) Urethral leakage (1) Sexual dysfunction (3)
Zhang et al[36]TME (100)R0/R1/R274.6 66.269 58.589.7 79Incomplete intestinal obstruction (4) Hydronephrosis (7)Incomplete intestinal obstruction (2.6) Hydronephrosis (10)
Masaki et al[19]TME (100)R0/R171.5 81.8NA87.6 91.7Anastomotic leakage (29) abscess (18) Small bowel obstruction (13)Anastomotic leakage (13) abscess (11) Small bowel obstruction (18)
Table 3 Results of meta-analysis and subgroup analysis by intraoperative radiotherapy compared with non-intraoperative radiotherapy for rectal cancer
Outcome indicators
Study type
NO of study
Patients, n IORT non-IORT
HR/OR/WMD (95% CI)
P value
Heterogeneity, χ2/ I2/ P value
5-yr overall survivalRCT3129 950.68 (0.29-1.63)0.3902.92/31.4%/0.233
Observational studies6321 2920.81 (0.66-1.11)0.1892.21/0.0%/0.819
Totality9450 3870.80 (0.60-1.06)0.1265.16/0.0%/0.740
5-yr disease free survivalRCT291 571.61 (0.74-3.53)0.2310.60/0.0%/0.440
Observational studies4235 2120.89 (0.68-1.16)0.3741.72/0.0%/0.633
Totality6326 2690.94 (0.73-1.22)0.6504.33/0.0%/0.503
5-yr local controlRCT3129 951.37 (0.35-5.35)0.6551.33/24.8%/0.249
Observational studies11487 5113.38 (1.73-6.57)0.00041.31/73.4%/0.000
Totality14616 6063.07 (1.66-5.66)0.00043.42/70.9%/0.000
AbscessRCT257 601.83 (0.65-5.11)0.2520.01/0.0%/0.905
Observational studies4205 2620.94 (0.53-1.66)0.8331.99/0.0%/0.575
Totality6262 3221.10 (0.67-1.80)0.7133.22/0.0%/0.665
FistulaeRCT172 680.75 (0.30-1.88)0.5420.00/NA/NA
Observational studies294 1751.22 (0.08-18.77)0.8882.02/50.4%/0.156
Totality3166 2430.79 (0.33-1.89)0.6002.07/3.2%/0.356
Wound complicationsRCT172 680.75 (0.30-1.88)0.5420.00/NA/NA
Observational studies7385 3931.06 (0.47-2.37)0.89316.09/62.7%/0.013
Totality8457 4611.21 (0.62-2.36)0.57517.01/58.8%/0.017
Anastomotic leakageRCT3129 952.18 (0.89-5.33)0.0870.11/0.0%/0.946
Observational studies4262 2660.66 (0.31-1.41)0.2832.46/0.0%/0.482
Totality7391 3611.09 (0.59-2.02)0.7756.57/8.7%/0.363
Neurogenic bladder dysfunctionObservational studies3187 1970.69 (0.31-1.55)0.3690.27/0.0%/0.874