Patient-reported outcome measures for technology assessment: A comparison between three-dimensional conformal and intensity-modulated radiotherapy in prostate cancer

BACKGROUND Technological innovation in radiotherapy demands evaluation not only through dosimetric or clinician-reported outcomes, but also through patient-centred measures. Patient-reported outcome measures (PROMs) provide a unique insight into how advances such as intensity-modulated radiotherapy (IMRT) affect daily functioning and quality of life, compared to conventional techniques. Despite the clear dosimetric benefits over three-dimensional conformal radiotherapy (3D-CRT), evidence on whether IMRT translates into superior patient-reported outcomes remains inconsistent. PROM-based assessment offers a robust framework to evaluate the real clinical value of radiotherapy technologies and their impact on long-term quality of life in localized prostate cancer. AIM To compare 3D-CRT and IMRT using PROMs and to examine the influence of image-guided techniques on outcomes. METHODS The observational study compared two independent cohorts of localized prostate cancer patients followed for five years: (1) 92 were treated with 3D-CRT (2003-2005); and (2) 106 with IMRT (2013-2019). PROMs were assessed using the expanded prostate cancer index composite and short form-36 health survey before treatment and annually, via centralized telephone interviews. Propensity score-weighted Generalized Estimating Equation models were constructed with adjustment for baseline differences. Within the IMRT cohort, a multivariate regression explored associations between image guidance, fractionation, and dose escalation and urinary outcomes 12 months post-treatment. RESULTS Both radiotherapy techniques were associated with sustained high long-term health-related quality of life, according to patient-reported data. Significant differences between modalities emerged from the second year or third year post-treatment in the expanded prostate cancer index composite urinary, bowel, and sexual domains. Patients treated with IMRT reported better trajectories in mental health (short form-36 health survey) compared with those treated with 3D-CRT. Within the IMRT cohort, the use of Cone-Beam Computed Tomography-based image guidance and reduced planning margins (≤ 5 mm) was associated with improved preservation of urinary continence (P = 0.048). Conversely, higher equivalent dose in 2-Gy fractions doses (> 78 Gy) and hypofractionation (≥ 3 Gy/fraction) were associated to greater short-term deterioration in urinary incontinence (P = 0.030) and irritative/obstructive symptoms (P = 0.006). CONCLUSION PROMs reveal the real-world impact of radiotherapy advances from the patient’s perspective. IMRT improved urinary and bowel outcomes, supporting PROMs as valid tools for technology assessment and patient-centred treatment optimization.