Intensity-modulated radiotherapy reduces gastrointestinal toxicity in pelvic radiation therapy with moderate dose

Abstract

This retrospective study was performed to evaluate and compare gastrointestinal (GI) toxicities caused by conventional radiotherapy (cRT) and intensity modulated radiotherapy (IMRT) in 136 cancer patients treated with pelvic radiotherapy (RT) with moderate radiation dose in a single institution. A matched-pair analysis of the two groups was performed; each group included 68 patients. Conventional RT was delivered using the four-field box technique and IMRT was delivered with helical tomotherapy. The median daily dose was 1.8 Gy and the median total dose was 50.4 Gy (range 25.2–56 Gy). Primary end point was GI toxicity during and after RT. Secondary end point was factors that affect toxicity. Patients treated with IMRT had lower incidence of grade ≥ 2 acute GI toxicity compared to the patients treated with cRT (p = 0.003). The difference remained significant in multivariate analysis (p = 0.01). The incidence of chronic GI toxicity was not statistically different between the two groups, but the cRT group had higher incidence of grade 3 chronic GI toxicity. Based on our results, IMRT can reduce GI toxicity compared to cRT in the treatment of pelvic radiotherapy even with moderate radiation dose and this will enhance patients’ quality of life and treatment compliance.

Simple calculation using anatomical features on pre-treatment verification CT for bladder volume estimation during radiation therapy for rectal cancer

“…[8,9] Modern techniques, such as IMRT and IGRT, can deliver smaller irradiation doses to the small bowel, resulting in less acute gastrointestinal toxicities in patients receiving pelvic RT. [10,11] The NRG/RTOG 1203 study showed that pelvic IMRT for cervical and endometrial cancer was related with significantly less gastrointestinal and urinary Abbreviations: CI confidence interval, SD standard deviation, V scan bladder volume measurement using bladder scan, V ratio bladder volume measurement using ratio of anatomical features toxicities than was standard RT, based on patientreported toxicities according to the Expanded Prostate Cancer Index Composite [10]. Despite this, 33.7% of patients receiving IMRT still developed frequent or almost constant diarrhea in the NRG/RTOG 1203 study.…”

Standard (8 weeks) vs long (12 weeks) Timing to Minimally-Invasive Surgery after NeoAdjuvant Chemoradiotherapy for Rectal cancer: a multicenter randomized controlled parallel group trial (TiMiSNAR)

“…Although results from comparative randomized clinical trial are not available yet, IMRT is usually associated with less dose to organ at risk, such as urinary bladder, small bowel and anal sphincters (in selected cases). This is translated into better clinical outcomes, in terms of gastrointestinal toxicity, genitourinary toxicity and skin side effects [16][17][18][19][20].…”

High precision radiotherapy including intensity-modulated radiation therapy and pulsed-dose-rate brachytherapy for cervical cancer: a retrospective monoinstitutional study

“…Brachytherapy (BT) as a boost to external beam radiotherapy (EBRT) is the gold standard in the curative management of locally advanced cervical cancer and significantly improves survival [2,3,4]. In the last decades, the development of intensity-modulated radiotherapy (IMRT) has resulted in the reduction of acute and chronic toxicity in pelvic radiotherapy compared to conventional three-dimensional (3D) conformal radiotherapy (CRT), with the same oncological outcome [5,6,7,8,9]. Concern-ing BT, radiation therapy centres around the world transited from low-dose-rate (LDR) to remote after-loading high-dose-rate (HDR) keeping the same oncological result, as demonstrated in a number of randomized trials [10,11,12,13,14,15,16].…”