Outcome After PSMA PET/CT-Based Salvage Radiotherapy in Patients with Biochemical Recurrence After Radical Prostatectomy: A 2-Institution Retrospective Analysis

Schmidt-Hegemann, Nina-Sophie; Stief, Christian; Kim, Tak-Hyun; Eze, Chukwuka; Kirste, Simon; Strouthos, Iosif; Li, Minglun; Schultze-Seemann, Wolfgang; Ilhan, Harun; Fendler, Wolfgang Peter; Bartenstein, Peter; Grosu, Anca-Ligia; Ganswindt, Ute; Belka, Claus; Meyer, Philipp T. und Zamboglou, Constantinos (2019): Outcome After PSMA PET/CT-Based Salvage Radiotherapy in Patients with Biochemical Recurrence After Radical Prostatectomy: A 2-Institution Retrospective Analysis. In: Journal of Nuclear Medicine, Bd. 60, Nr. 2: S. 227-233

Abstract

Prostate-specific membrane antigen (PSMA) PET/CT detects prostate cancer recurrence at low levels of prostate-specific antigen (PSA). Radiotherapy with dose escalation to the former prostate bed has been associated with improved biochemical recurrence-free survival (BRFS). Thus, we hypothesized that PSMA PET/CT-guided salvage radiotherapy leads to improved BRFS. Methods: In total, 204 consecutive patients were referred for salvage radiotherapy after radical prostatectomy. PSMA PET/CT scans were performed, and patients with PSA persistence (109 patients) or evidence of distant metastases (5 patients) were excluded from this analysis. Thus, the following analysis is based on a total of 90 patients who underwent PSMA PET/CT before radiotherapy due to biochemical recurrence and received salvage radiotherapy. In cases of PET-positive findings, antiandrogen therapy was commenced before initiation of radiotherapy. BRFS (PSA <= 0.2 ng/mL) was defined as the study endpoint. Results: PET-positive lesions were detected in 42 of 90 (47%) patients, 24 of 42 (27%) being fossa recurrence only, 12 of 42 (13%) pelvic lymph node only, and 6 of 42 (7%) both fossa and pelvic lymph node. The median PSA before radiotherapy was 0.44 ng/mL (range, 0.11-6.24 ng/mL). Cumulatively, a total dose of 70.0 Gy (range, 67.2-72 Gy) was delivered to local macroscopic tumor, 66 Gy (range, 59.4-70.2 Gy) to the prostatic fossa, 60.8 Gy (range, 54-66 Gy) to PET-positive lymph nodes, and 50.4 Gy (range, 45-50.4 Gy) to the lymphatic pathways. After a median follow-up of 23 mo, BRFS was 78%. Anti-androgen therapy was ongoing in 4 patients at the last follow-up. No significant difference in BRFS between PET-positive patients (74%) and PET-negative patients (82%;P > 0.05) was observed at the last follow-up. Two patients had late genitourinary toxicity, grade 3, and no patient had gastrointestinal toxicity of grade 3 or higher (National Cancer Institute common terminology criteria for adverse events, version 4.03). Conclusion: PSMA PET/CT-guided salvage radiotherapy is an effective and safe local treatment option. No difference in BRFS between PET-positive and PET-negative patients was observed, indicating effective targeting of PET-positive lesions. PSMA PET/CT when readily available should be offered to patients with PSA recurrence for treatment individualization.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Medizin
• Themengebiete: 600 Technik, Medizin, angewandte Wissenschaften > 610 Medizin und Gesundheit
• ISSN: 0161-5505
• Sprache: Englisch