68 Ga-PSMA PET/CT-based metastasis-directed radiotherapy for oligometastatic prostate cancer recurrence after radical prostatectomy

• Published in: World journal of urology Vol. 37; no. 8; p. 1535
• Main Authors: Artigas, C, Flamen, P, Charlier, F, Levillain, H, Wimana, Z, Diamand, R, Albisinni, S, Gil, T, Velthoven, R Van, Peltier, A, Gestel, D Van, Roumeguere, T, Otte, F-X
• Format: Journal Article
• Language: English
• Published: Germany 01.08.2019
• Subjects: Aged; Aged, 80 and over; Humans; Male; Membrane Glycoproteins; Middle Aged; Neoplasm Metastasis; Neoplasm Recurrence, Local - radiotherapy; Organometallic Compounds; Positron Emission Tomography Computed Tomography - methods; Prostatectomy - methods; Prostatic Neoplasms - diagnostic imaging; Prostatic Neoplasms - pathology; Prostatic Neoplasms - radiotherapy; Prostatic Neoplasms - surgery; Radiopharmaceuticals; Radiotherapy, Image-Guided; Retrospective Studies; Treatment Outcome; PSMA; Oligometastatic; Metastasis-directed therapy; Radiotherapy; Prostate cancer
• ISSN: 1433-8726

The aim of this communication was to assess the efficacy of directed oligometastatic radiotherapy (RT) based on Ga-PSMA PET/CT in patients with prostate cancer (PCa) biochemical relapse (BCR) after primary treatment with curative intent. This is a retrospective analysis of a monocentric cohort of PCa patients diagnosed with oligometastatic disease on Ga-PSMA PET/CT and treated with metastasis-directed RT. Inclusion criteria were: histologically proven PCa, BCR after primary treatment with curative intent, oligometastatic disease defined as ≤ 3 metastatic lesions. To evaluate the efficacy of the therapy, biochemical response defined as a decrease of > 50% of PSA (PSA ) was measured at 1 and 4 months. Patients were followed up until progression and start of androgen deprivation therapy (ADT). BCR-free survival and ADT-free survival were calculated. 20 patients met the inclusion criteria. Median PSA value: 1.4 ng/ml (IQR, 0.3-2.3 ng/ml). A total of 30 PSMA-positive lesions were treated: 18 lymph nodes (60%), nine bone (30%) and three visceral lesions (10%). Median follow-up was 15 months (range 4-33 months). Biochemical response at 1 and 4 months was found in 3/20 patients (15%) and 14/20 (70%), respectively. BCR-free survival rate at 1 year was 79% and 53% at 2 years. ADT-free survival at 2 years was 74%. This retrospective study suggests that metastasis-directed RT based on Ga-PSMA PET/CT may be a valuable treatment in patients with PCa oligometastatic disease, providing promising BCR-free survival rates and potentially postponing ADT for at least 2 years in 74% of the patients. Response assessment should not be measured before 4 months after treatment.