PSMA PET‐based stereotactic body radiotherapy for locally recurrent prostate cancer after definitive first‐line therapy

Abstract

AbstractBackgroundAdvances in prostate‐specific membrane antigen (PSMA) PET–computed tomography (CT) and magnetic resonance imaging (MRI) allow the detection and localization of exclusively local prostate‐cancer‐recurrences after definitive first‐line therapy. PSMA‐based early detection of circumscribed local recurrences followed by hypofractionated high‐precision stereotactic body radiotherapy (SBRT) might yield long‐term disease control at moderate rates of adverse effects.MethodsRetrospective analysis of 35 patients treated for locally recurrent prostate cancer between November 2012 and December 2021 with PSMA PET‐ and MRI‐based robotic SBRT.ResultsThirty‐five patients treated with local prostate cancer recurrence post surgery, post surgery, and adjuvant/salvage radiotherapy (RT) and after definitive RT. All but one patients had fractionated SBRT in 3–5 fractions. Median progression‐free survival (PFS) was 52.2 months for all patients and 52.2 months in the radical prostatectomy (RPE) group, 31.2 months in the RPE + RT group and not reached in the RT group. The most common event was increased urinary frequency grade 1–2. 54.3% of all patients had no acute and 79.4% no late toxicity during follow‐up.DiscussionOur PFS of 52.2 months (RPE), 31.2 months (RPE + RT) and not reached (RT) compares favorably with published data. This method constitutes a valid alternative to morbidity‐prone invasive approaches or palliative systemic therapy.