Assessing concordance between patient-reported and investigator-reported CTCAE after proton beam therapy for prostate cancer

Roman O. Kowalchuk, David Hillman, Thomas B. Daniels, Carlos E. Vargas, Jean Claude M. Rwigema, William W. Wong, Bradley J. Stish, Amylou C. Dueck, Richard Choo

Research output: Contribution to journalArticlepeer-review


Purpose: We report acute patient-reported outcomes using CTCAE (PRO-CTCAE) of proton beam radiotherapy for high-risk or unfavorable intermediate-risk prostate cancer in a prospective clinical trial. PRO-CTCAE were correlated with investigator reported-CTCAE (IR-CTCAE) to assess the degree of concordance. Methods and materials: 11 PRO-CTCAE questions assessed gastrointestinal (GI), genitourinary (GU), or erectile function side effects. The correlation scheme between PRO-CTCAE and IR-CTCAE was independently developed by two physicians. Analyses of PRO-CTCAE and IR-CTCAE were conducted using both descriptive terms and the converted grade scores. The Kappa statistic described the degree of concordance. Results: 55 patients were included. IR-CTCAE underestimated diarrhea compared to PRO-CTCAE at the end of treatment (EOT), with a 28% rate of underestimation (11% by ≥ 2 toxicity grades). Similarly, urinary tract pain was underestimated in 45% of cases (17% by ≥ 2 grades) at EOT. Differences were less pronounced at baseline or 3 months after radiotherapy. The incidence of urinary urgency and frequency tended to be overestimated prior to treatment (36% and 24%, respectively) but underestimated at EOT (35% and 31%, respectively). The degree of interference with daily activities was consistently overestimated by investigators (45%-85%). Finally, erectile dysfunction showed a 36–56% rate of discordance by ≥ 2 toxicity grades. Conclusions: Our study shows a low agreement between IR-CTCAE and PRO-CTCAE in the setting of proton therapy for prostate cancer. Compared to patient-reported outcomes, physicians underestimated the frequency and severity of urinary symptoms and diarrhea at the end of treatment. Continued use of PROs should be strongly encouraged.

Original languageEnglish (US)
Pages (from-to)34-41
Number of pages8
JournalClinical and Translational Radiation Oncology
StatePublished - Nov 2021


  • Patient-reported outcomes
  • Prostate cancer
  • Proton beam therapy
  • Toxicity

ASJC Scopus subject areas

  • Oncology
  • Radiology Nuclear Medicine and imaging


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