KEY POINTS
- This substudy used data from 1,180 men enrolled in HYPO-RT-PC, randomized to conventional RT (2.0 Gy ×39) or ultra-hypofractionated RT (6.1 Gy ×7).
- Patient-reported urinary, bowel, erectile, and sexual symptoms were compared with clinician RTOG assessments at baseline, the end of RT, and 1, 2, and 4 years after treatment.
- Depending on timepoint, 580–910 paired assessments were available. Correlations between patient and clinician scores ranged widely from −0.091 to 0.750, demonstrating substantial variation between symptom domains.
- Urinary symptoms showed particularly poor concordance. At baseline, nearly 50% of patients reported no urinary symptoms, while clinicians recorded no symptoms in approximately 80%, indicating substantial under-recognition even before treatment.
- Discordance peaked at treatment completion: clinicians underestimated urinary symptoms in 52% of paired assessments, while perfect agreement fell to approximately 35% and almost 20% had a difference of two or more severity grades.
- Bowel symptoms followed a similar pattern, with 46% underestimated by clinicians at the end of RT. Baseline bowel agreement had been considerably better at 76%.
- Sexual outcomes behaved differently. Clinicians generally rated problems with sexual activity as more severe than patients did, while erectile-dysfunction agreement changed over time. Correlation for sexual activity remained >0.70 across assessments.
- Fractionation had relatively little influence on the overall disagreement pattern: no significant treatment-arm differences were seen for urinary symptoms, erectile dysfunction, or sexual activity, with differences limited mainly to bowel assessments at selected timepoints.
- PCSS and RTOG are not equivalent instruments; patient responses had to be recoded to permit comparison, and the investigators predefined patient reporting as the reference standard.
CLINICAL TAKEAWAY
Clinician toxicity grading and patient symptom reporting are not interchangeable. In prostate RT, relying on clinician assessment alone risks systematically missing urinary and bowel burden precisely when symptoms are most pronounced, providing a strong argument for routine collection and active review of PROMs during follow-up.