ESTRO 2024 - Abstract Book

S2348

Clinical - Urology

ESTRO 2024

recurrence was identified. Per our experience, the persistently elevated PSA level after the retreatment often suggests the coexistence of remote prostate metastatic cancerous lesions. In addition, from this investigated group, only 6.8% of cases reported having either grade II (n = 2) or grade III (n = 1) symptoms of proctitis.

Conclusion:

The single institutional results presented in this retrospective study, with over 21-month follow-ups, imply a favorite clinical efficacy in salvage proton retreatment for localized recurrent prostate cancer post the initial definitive localized radiation therapy i. In this series, about 30% showed PSA reduction of more than 1.0 ng/mL, and half of all cases showed PSA reduction after the localized retreatment. Per IPSS for adverse effect evaluation, nearly 80% experienced only mild symptoms, and no more than 5% (2 out of 44 cases) had severe symptoms. Grade II and III symptoms for proctitis are found in less than 7% (3 out of 44) of patients. The volumetric dosimetric values of the rectum, bladder, and urethra suggest a practical reference for such treatment in the future.

Keywords: Retreatment, Proton therapy, Prostate cancer

References:

[i] Valle LF, et al.: “A Systematic Review and Meta-analysis of Local Salvage TherapiesAfter Radiotherapy for Prostate Cancer (MASTER)”. Euro Urol 2021; 80:280 -292

[ii] Kole TP, et al.: Acta Oncologica, 2016; 54: 825-831

[iii] Wu Y-Y, Fan K- H: “Proton therapy for prostate cancer: current state and future perspectives”. Br J Radiol 2022; 95: 20210670