Stereotactic Body Radiotherapy for Oligoprogression in Castration-Resistant Prostate Cancer: Early Toxicity Analysis of the TRAP Trial

• Published in: Clinical oncology (Royal College of Radiologists (Great Britain)) 2024-09, Vol.36 (9), p.585-592
• Main Authors: Patel, P.H., Dreibe, S., Reid, A., Parker, C., Murray, J., Pathmanathan, A., Tirona, A., Guevara, J., Suh, Y.-E., Frew, J., Palaniappan, N., Syndikus, I., Attard, G., Tunariu, N., Tree, A.C.
• Format: Article
• Language: English
• Subjects: Abiraterone; Aged; Aged, 80 and over; androgen receptor targeted agents; Androstenes - therapeutic use; Benzamides - therapeutic use; Disease Progression; enzalutamide; Humans; Male; Middle Aged; Nitriles - therapeutic use; oligoprogression; Phenylthiohydantoin - therapeutic use; Progression-Free Survival; prostate cancer; Prostatic Neoplasms, Castration-Resistant - pathology; Prostatic Neoplasms, Castration-Resistant - radiotherapy; Quality of Life; Radiosurgery - adverse effects; Radiosurgery - methods; stereotactic body radiotherapy
• ISSN: 0936-6555; 1433-2981; 1433-2981
• DOI: 10.1016/j.clon.2024.06.047

To assess toxicity and patient quality of life after stereotactic body radiotherapy (SBRT) to oligoprogressive disease (OPD) in patients with metastatic castrate-resistant prostate cancer (CRPC) on androgen receptor targeted agents (ARTA). This phase II trial enrolled patients with metastatic CRPC with ≤ 2 oligoprogressive lesions in bone, lymph node, lung, or prostate. All patients were receiving systemic treatment with abiraterone or enzalutamide at the time of oligoprogression. All patients received SBRT to the OPD site(s) and continued the current ARTA. Patients received 30 Gy in 5 fractions (alternate days) to the OPD site. The primary endpoint of the trial is to assess if SBRT to OPD sites results in progression free survival of >6 months. The primary endpoint for this toxicity analysis is the rate of grade 3 or higher adverse events at any timepoint up to 6 months after SBRT. Secondary endpoints included comparing pre- and post-SBRT patient-related outcomes reported using visual analogue scale scores and EQ-5D health questionnaire. Forty enrolled patients had at least 6 months of follow-up at the time of analysis. Grade 3 or higher toxicity from any cause recorded using common terminology criteria for adverse events and radiation therapy oncology group was found in 8/40 (20%) of patients, but only 1/40 (2.5%) was deemed possibly related to SBRT. There was no significant difference in mean EQ5D visual analogue scale score from baseline to each timepoint after SBRT (p = 0.449). In this prospective phase II clinical trial for OPD whilst on ARTA in the CRPC setting, we report low grade ≥ 3 toxicity after SBRT. There is no discernible change in patient-reported quality of life due to SBRT treatment. The final results of progression-free survival and toxicity of SBRT treatment will be reported once further follow-up is complete. •Stereotactic radiotherapy to oligoprogressive disease in metastatic prostate cancer patients on targeted agents is feasible.•Stereotactic body radiotherapy is well tolerated in patients with castrate-resistant prostate cancer.•There is minimal treatment-related effect on quality of life and patient-reported outcomes.