Stereotactic body radiotherapy for bone oligometastatic disease in prostate cancer

• Published in: World journal of urology Vol. 37; no. 12; pp. 2615 - 2621
• Main Authors: Patel, Priyanka H., Chaw, Cheng Lee, Tree, Alison C., Sharabiani, Mansour, van As, Nicholas J.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-12-2019; Springer Nature B.V
• Subjects: Adult; Aged; Aged, 80 and over; Bone cancer; Bone Neoplasms - radiotherapy; Bone Neoplasms - secondary; Clinical trials; Cohort Studies; Humans; Lymph nodes; Male; Medical prognosis; Medicine; Medicine & Public Health; Metastases; Metastasis; Middle Aged; Nephrology; Oncology; Prostate cancer; Prostatic Neoplasms - pathology; Prostatic Neoplasms - radiotherapy; Radiation therapy; Radiosurgery; Retrospective Studies; Survival; Topic Paper; Urology; Stereotactic body radiotherapy; Prostate cancer; Oligometastatic disease; Bone metastases
• ISSN: 0724-4983; 1433-8726
• DOI: 10.1007/s00345-019-02873-w

Purpose
There are sparse data describing outcomes of bone-only oligometastatic prostate cancer in comparison with lymph node disease treated with stereotactic body radiotherapy (SBRT). The primary aim of this study was to report progression-free survival (PFS) data for patients with bone-only disease. Influence of hormone sensitivity and androgen deprivation therapy use was also assessed.
Methods
This is a single-centre retrospective cohort study. Hormone-sensitive and castrate-resistant patients with oligometastatic (≤ 3) bone-only prostate cancer treated with SBRT were included. Data were collected using electronic records. Kaplan–Meier survivor function, log rank test, as well as Cox regression were used to calculate PFS and overall survival.
Results
In total, 51 patients with 64 bone metastases treated with SBRT were included. Nine patients were castrate resistant and 42 patient’s hormone sensitive at the time of SBRT. Median follow-up was 23 months. Median PFS was 24 months in hormone-sensitive patients and 3 months in castrate-resistant patients. No patients experienced grade 3 or 4 toxicities. There were three in-field recurrences.
Conclusions
In this study, patients with bone oligometastatic disease showed potential benefit from SBRT with a median PFS of 11 months. Hormone-sensitive patients showed the greatest benefit, with results similar to that published for oligometastatic pelvic nodal disease treated with SBRT. Prospective randomised control trials are needed to determine the survival benefit of SBRT in oligometastatic bone-only prostate cancer and to determine prognostic indicators.