Less Toxicity With Pelvic IMRT vs Standard RT in Cervical and Endometrial Cancers
In the phase III NRG Oncology-RTOG 1203 study, patient-reported gastrointestinal (GI) and urinary toxicities were reduced with intensity-modulated radiation therapy (IMRT) vs standard radiotherapy (RT) in women with cervical or endometrial cancer. The findings were reported by Klopp et al in the Journal of Clinical Oncology.
In the trial, 278 eligible patients with invasive disease were randomized between 2012 and 2015 to receive pelvic IMRT (n = 129) or standard 4-field RT (n = 149). Randomization was stratified by RT dose of 45 Gy (59% of the IMRT group vs 56% of the standard RT group) vs 50.4 Gy, use of cisplatin chemotherapy (26% vs 25%), and disease of the cervix (16% vs 16%) vs endometrium. Patients received 45 Gy or 50.4 Gy on the basis of physician preference. Patients received 5 cycles of cisplatin at 40 mg/m2 weekly at physician discretion according to predefined pathologic criteria.
The primary endpoint was change in patient-reported acute GI toxicity from baseline to the end of RT in the bowel domain of the Expanded Prostate Cancer Index Composite (EPIC).
Toxicity Outcomes
The mean EPIC bowel score declined by 18.6 points in the IMRT group vs 23.6 points in the standard RT group (P = .048), with the difference being greatest in the bowel function subscale (decline of 14.5 vs 21.0 points, P = .02). Mean EPIC urinary score decreased by 5.6 points in the IMRT group vs 10.4 points in the standard RT group (P = .03).
A borderline significant smaller adverse effect on quality of life as measured by Trial Outcome Index score was observed in the IMRT group (mean decrease of 8.8 vs 12.8 points, P = .06). At the end of RT, frequent or almost-constant diarrhea was reported by 33.7% vs 51.9% of patients (P = .01), and 7.8% vs 20.4% (P = .04) reported using antidiarrheal medications at least 4 times daily.
The investigators concluded, “Pelvic IMRT was associated with significantly less GI and urinary toxicity than standard RT from the patient’s perspective.”
The study was supported by grants from the National Cancer Institute.
Ann H. Klopp, MD, of the Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, is the corresponding author for the Journal of Clinical Oncology article.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
