Chronic Prostate Cancer-Related Symptoms and Toxicities Following Stereotactic Body Radiation Therapy: Implications for Future Radionuclide Therapy

Diya Kallam; Kelly Gaudian; Ryan Collins; Zoya Zwart; Min Ji Koh; Malika T Danner; Alan L Zwart; Deepak Kumar; Suy Simeng; Lisa Gudenkauf; Mark Fallick; Giuseppe Esposito; Brian Gonzalez; Sean Collins

doi:10.7759/cureus.85034

Chronic Prostate Cancer-Related Symptoms and Toxicities Following Stereotactic Body Radiation Therapy: Implications for Future Radionuclide Therapy

Cureus. 2025 May 29;17(5):e85034. doi: 10.7759/cureus.85034. eCollection 2025 May.

Authors

Diya Kallam¹, Kelly Gaudian², Ryan Collins³, Zoya Zwart⁴, Min Ji Koh⁴, Malika T Danner⁴, Alan L Zwart⁴, Deepak Kumar⁵, Suy Simeng⁶, Lisa Gudenkauf⁷, Mark Fallick⁸, Giuseppe Esposito⁹, Brian Gonzalez⁷, Sean Collins¹⁰

Affiliations

¹ Radiation Oncology, George Washington University School of Medicine and Health Sciences, Washington, D.C., USA.
² Radiation Oncology, Washington University School of Medicine, St. Louis, USA.
³ Radiation Oncology, College of William and Mary, Williamsburg, USA.
⁴ Department of Radiation Oncology, Georgetown University, Washington, D.C., USA.
⁵ Julius L. Chambers Biomedical/Biotechnology Research Institute, North Carolina Central University, Durham, USA.
⁶ Department of Radiation Medicine, Georgetown University, Washington, D.C., USA.
⁷ Radiation Oncology, Moffitt Cancer Center, Tampa, USA.
⁸ Radiation Oncology, Novartis, East Hanover, USA.
⁹ Department of Nuclear Medicine, Georgetown University, Washington, D.C., USA.
¹⁰ Radiation Oncology, Tampa General Hospital, Tampa, USA.

Abstract

Background Men treated for prostate cancer can experience a high symptom burden. Stereotactic body radiation therapy (SBRT) is increasingly utilized in the management of localized prostate cancer, while radionuclide therapy (RNT) is rapidly becoming a standard treatment option for metastatic prostate cancer. The Functional Assessment of Cancer Therapy-Radionuclide Therapy (FACT-RNT) is a newly validated questionnaire assessing symptoms and toxicities among patients receiving RNT. This study aimed to characterize long-term, patient-reported symptoms in prostate cancer survivors treated with SBRT using the FACT-RNT questionnaire, and to explore whether such symptoms may inform risk stratification for future RNT candidacy. Methodology We conducted a cross-sectional assessment of symptoms and toxicities after prostate SBRT using the FACT-RNT, a 15-item questionnaire assessing common RNT-related symptoms and toxicities across several domains, including fatigue, salivary/lacrimal gland dysfunction, gastrointestinal (GI) difficulties, and pain. Responses to individual questions were grouped into three clinically relevant categories (i.e., absent ("not at all"), mild ("a little bit" to "somewhat"), moderate to severe ("quite a bit" to "very much")). Standard error was calculated at a 95% confidence interval. However, there are methodological limits to linking SBRT symptoms directly with RNT tolerance. Results Prostate cancer patients (N = 296) who had completed SBRT a median of six years prior (range = 0-13 years) completed the FACT-RNT questionnaire at a response rate of 49.5% (296 of 598 consented patients). Patients completed prostate SBRT at a median of six years before questionnaire administration (range = 0-13 years). The median age of responders was 78 years, 76% of patients were white, and 69% were of intermediate risk disease. Overall, 25% of respondents were mildly (21%) or moderately to severely (4%) bothered by treatment side effects. Respondents endorsed at least mild fatigue (53%), xerostomia (29%), constipation (23%), and pain (20%). Conclusions A notable percentage of prostate cancer patients treated with SBRT report toxicities commonly associated with RNT, such as fatigue, salivary/lacrimal gland dysfunction, GI difficulties, and pain. Results of this study underscore the importance of administering the FACT-RNT before RNT treatment to obtain a baseline assessment of symptoms, evaluate pre-treatment risk for RNT toxicities (e.g., salivary gland dysfunction), and better differentiate baseline abnormalities in function from RNT-related side effects.

Keywords: nuclear medicine; prostate cancer; quality of life (qol); radiation oncology education; radioligand therapy.