Five-Week Radiation Course Matches Seven-Week Standard After Prostate Cancer Surgery, Trial Finds

Men who undergo surgery for high-risk prostate cancer often face a second ordeal if laboratory tests show that prostate-specific antigen levels are climbing again: a course of postoperative radiation therapy delivered to the prostate bed. For decades, that treatment has followed a conventional template of 37 individual sessions spread over roughly seven weeks, a schedule that demands dozens of hospital visits and can strain patients who live far from treatment centers or who must balance therapy against work and family obligations. Now, five-year results from a large Phase III trial conducted by the NRG Oncology research network suggest that a substantially compressed schedule can deliver comparable cancer control and comparable quality of life, even as it raises new questions about a specific category of urinary side effects that physicians, rather than patients, tend to notice first.

The trial, known as NRG-GU003, compared two distinct ways of fractionating radiation after prostatectomy. The conventional approach, abbreviated COPORT, delivered a total dose of 66.6 Gy to the prostate bed in 37 fractions of 1.8 Gy each. The hypofractionated approach, abbreviated HYPORT, delivered a slightly lower total dose of 62.5 Gy in just 25 fractions of 2.5 Gy each, compressing the entire course into approximately five weeks. Fractionation is a central concept in radiation oncology: because normal tissues repair sublethal DNA damage between treatments, splitting a dose into many small fractions spares healthy structures such as the bladder and rectum. Hypofractionation deliberately uses larger daily doses over fewer visits, exploiting improvements in treatment precision while betting that the tumor responds more strongly to bigger per-fraction doses than surrounding organs do. The trade-off is that each fraction tests the tolerance of nearby healthy tissue more aggressively.

The study enrolled 296 eligible patients, a sample size that gives the comparison meaningful statistical weight. Before randomization, investigators stratified participants by their baseline scores on the Expanded Prostate Cancer Index Composite, a validated questionnaire that captures urinary and bowel function, and by whether they had previously received androgen deprivation therapy, the hormonal treatment often paired with radiation in high-risk disease. Patients were then randomly assigned to one of the two radiation schedules. The primary objective was to determine whether HYPORT was noninferior to COPORT with respect to patient-reported urinary and bowel symptoms at two years, a design that asks not whether the shorter schedule is better, but whether it is acceptably close to the standard.

By that primary yardstick, the shorter schedule held up. The mean changes in patient-reported outcomes from baseline to five years were similar between the two arms for bowel symptoms, urinary symptoms, and overall quality of life as measured by the EQ-5D instrument. Bowel symptom scores shifted by 0.6 points in the conventional arm versus minus 2.0 points in the hypofractionated arm, a difference that was not statistically significant. Urinary symptom scores moved by minus 5.7 versus minus 8.0 points, and EQ-5D scores by minus 0.01 versus 0.0, again without significant differences. In practical terms, patients treated in five weeks reported essentially the same subjective experience over five years as those treated across seven.

Cancer control outcomes also favored equivalence. With a median follow-up of seven years, biochemical failure at five years occurred in 18 percent of men treated conventionally versus 21 percent of men treated with the shorter schedule, a difference that did not reach statistical significance. Biochemical failure, detected through rising PSA levels, is the earliest and most closely watched signal of returning disease after surgery. Across both arms, 31 deaths were reported in total, including four from prostate cancer, underscoring that neither schedule produced an excess of fatal events. For a disease in which postoperative radiation is delivered specifically to preserve the chance of cure, the demonstration that the compressed course did not compromise long-term control is the trial’s most consequential finding.

The picture grows more nuanced, however, when toxicity is examined through the physician’s eyes rather than the patient’s. At five years, grade 3 adverse events of any kind were more common in the hypofractionated arm, occurring in 16 percent of patients compared with 7 percent in the conventional arm, a statistically significant difference. The excess was concentrated in renal and urinary disorders, which affected 13 percent of hypofractionated patients versus 3 percent of conventional patients. Within that category, noninfective cystitis, inflammation of the bladder, occurred in 7 percent of the shorter-schedule patients and none of the conventional patients, while hematuria, blood in the urine, occurred in 6 percent versus 0.7 percent. Importantly, no grade 4 or grade 5 radiation-related adverse events were recorded in either arm, and the time to onset of grade 3 events did not differ between groups.

Mark Buyyounouski, MD, MS, FASTRO, of Stanford University and lead author of the NRG-GU003 manuscript, framed the results around the practical realities of treatment access. Postoperative radiation, he noted, is an important part of preserving the opportunity for cure in patients with PSA recurrence after prostatectomy, yet the traditional 37 sessions over approximately seven weeks can make treatment difficult for some patients to receive and burdensome for those who do. The findings, he said, show that postoperative radiation can be delivered in a shorter five-week course of 25 treatments without compromising long-term cancer control or patient-reported quality of life. For radiation oncology departments, a 12-fraction reduction per patient translates into meaningful gains in chair time, machine capacity, and patient convenience.

The divergence between what patients report and what physicians record is a recurring theme in modern oncology trials, and Buyyounouski addressed it directly. While long-term patient-reported urinary outcomes were similar, physician-reported grade 3 urologic toxicity was increased with hypofractionation, and the reason for that difference is unknown, he observed. Physician-reported toxicity primarily captures clinical events and the interventions they require, while patient-reported outcomes capture symptoms, function, and how treatment affects daily life. These measures provide different, complementary perspectives on treatment effects. A patient may experience bladder irritation that resolves without dramatic intervention, while a physician may document a clinically significant event requiring medication or procedural management, and the two lenses need not align.

The results were presented during the Clinical Trials Session of the 2026 American Society for Radiation Oncology Annual Meeting in Boston, Massachusetts, placing them before the community of specialists who set fractionation standards worldwide. The trial’s support came from the National Cancer Institute, part of the National Institutes of Health, through grants funding the NCORP research base, the NRG Oncology statistical and data management center, NRG Oncology operations, and imaging and radiation quality assurance. NRG Oncology itself, founded in 2012 as a Pennsylvania-based nonprofit, integrates the legacy research programs of the National Surgical Adjuvant Breast and Bowel Project, the Radiation Therapy Oncology Group, and the Gynecologic Oncology Group, and operates through more than 1,300 research sites worldwide.

For clinicians weighing the findings in the clinic, the decision will hinge on how much weight to give the toxicity signal against the benefits of a shorter course. Buyyounouski concluded that physicians will need to decide how much weight to give the toxicity findings when choosing a fractionation schedule, particularly when a shorter course could improve access to care, reduce treatment burden, or even make postoperative radiation possible for patients who would otherwise forgo it. A five-week schedule that preserves biochemical control and patient-reported quality of life may extend curative-intent treatment to men for whom seven weeks of daily visits was never realistic, while the modest but real increase in grade 3 cystitis and hematuria gives treating physicians a concrete, quantifiable trade-off to discuss with each patient before the first fraction is delivered.

Subject of Research: Hypofractionated versus conventional postprostatectomy radiotherapy for high-risk prostate cancer

Article Title: Shortened radiation schedule provides similar cancer control and patient-reported outcomes to standard radiation following surgery for high-risk prostate cancer in NRG Oncology trial

Article References: Shortened radiation schedule provides similar cancer control and patient-reported outcomes to standard radiation following surgery for high-risk prostate cancer in NRG Oncology trial. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: prostate cancer, radiation therapy, hypofractionation, postprostatectomy radiotherapy, NRG Oncology, NRG-GU003, clinical trial, biochemical failure, patient-reported outcomes, urinary toxicity, ASTRO, radiation oncology