Boston, MA—Patients with cervical and endometrial cancers experience fewer gastrointestinal and genitourinary adverse events and have improved quality of life when they receive intensity-modulated radiation therapy (IMRT) compared with conventional radiation therapy, according to the results of a recent study presented at the 2016 Annual Meeting of the American Society for Radiation Oncology (ASTRO).
“The way that radiation is performed has a major impact on the risk of side effects from treatment. We know that IMRT reduces the amount of normal tissue irradiated, so we suspected it would have fewer side effects. [Our study is one of the first] to rigorously ask this question using patient questionnaires to ensure that the lower doses resulted in meaningful differences in patients’ experiences during treatment,” said lead investigator, Ann Klopp, MD, PhD, the University of Texas M.D. Anderson Cancer Center, Houston.
The study included 278 patients with cervical or endometrial cancer treated with postoperative pelvic radiation therapy at centers in North America, Japan, and Korea. Patients were stratified based upon radiation therapy dose (45 Gy or 50.4 Gy), chemotherapy (0 or 5 cycles of weekly cisplatin), and disease site, and were then randomized to receive standard radiation therapy or IMRT.
Several patient-reported outcomes measures were used, including the Expanded Prostate Cancer Index Composite (EPIC) for bowel and urinary toxicities; Patient-Reported Outcomes–Common Terminology Criteria for Adverse Events for gastrointestinal and genitourinary adverse events; and Functional Assessment of Cancer Therapy–General with cervix subscale to track health-related quality of life.
IMRT resulted in significantly fewer bowel-related toxicities compared with radiation therapy on the EPIC measure: −18.6 points versus −23.6 points, respectively. Patients receiving IMRT had less diarrhea and fecal incontinence, with 1 in 5 women in the standard radiation therapy group reporting taking ≥4 antidiarrheal medications daily compared with 7.8% of women in the IMRT group (P = .04).
The frequency of urinary side effects was also lower in the IMRT group. IMRT had significantly less of a negative impact on patients’ quality of life than standard radiation therapy, according to the Functional Assessment of Cancer Therapy–General (P = .06). In addition, patients in the IMRT group had less change in physical well-being and fewer additional concerns than those in the conventional radiation therapy group.
“Many radiation oncologists already use IMRT for women undergoing pelvic radiation, but this research provides data that using IMRT, which is a more resource-intensive treatment, makes a real difference to patients….When performed by an experienced radiation oncology team, IMRT reduces the risk of short-term bowel and bladder side effects for patients with cervical and endometrial cancer,” Dr Klopp said.