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Bowden P, See AW, Frydenberg M, Haxhimolla H, Costello AJ, Moon D, Ruljancich P, Grummet J, Crosthwaite A, Pranavan G, Peters JS, So K, Gwini SM, McKenzie DP, Nolan S, Smyth LML, Everitt C. Fractionated stereotactic body radiotherapy for up to five prostate cancer oligometastases: Interim outcomes of a prospective clinical trial. Int J Cancer 2020; 146:161-168. [PMID: 31199504 DOI: 10.1002/ijc.32509] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 05/23/2019] [Accepted: 05/29/2019] [Indexed: 02/02/2023]
Abstract
Stereotactic body radiotherapy (SBRT) can delay escalation to systemic treatment in men with oligometastatic prostate cancer (PCa). However, large, prospective studies are still required to evaluate the efficacy of this approach in different patient groups. This is the interim analysis of a prospective, single institution study of men relapsing with up to five synchronous lesions following definitive local treatment for primary PCa. Our aim was to determine the proportion of patients not requiring treatment escalation following SBRT. In total, 199 patients were enrolled to receive fractionated SBRT (50 Gray in 10 fractions) to each visible lesion. Fourteen patients were castration resistant at enrolment. The proportion of patients not requiring treatment escalation 2 years following SBRT was 51.7% (95% CI: 44.1-59.3%). The median length of treatment escalation-free survival over the entire follow-up period was 27.1 months (95% CI; 21.8-29.4 months). Prior androgen deprivation therapy (ADT) predicted a significantly lower rate of freedom from treatment escalation at 2 years compared to no prior ADT (odds ratio = 0.21, 95% CI: 0.08-0.54, p = 0.001). There was no difference in the efficacy of SBRT when treating 4-5 vs. 1-3 initial lesions. A prostate-specific antigen (PSA) decline was induced in 75% of patients, with PSA readings falling to an undetectable level in six patients. No late grade three toxicities were observed. These interim results suggest that SBRT can be used to treat up to five synchronous PCa oligometastases to delay treatment escalation.
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Affiliation(s)
| | | | - Mark Frydenberg
- Department of Surgery, Monash University, Clayton, VIC, Australia.,Australian Urology Associates, Melbourne, VIC, Australia
| | - Hodo Haxhimolla
- Department of Urology, The Canberra Hospital, Canberra, ACT, Australia.,Australian National University, Canberra, ACT, Australia
| | - Anthony J Costello
- Department of Surgery, University of Melbourne, Parkville, VIC, Australia
| | - Daniel Moon
- Department of Surgery, University of Melbourne, Parkville, VIC, Australia.,Division of Cancer Surgery, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia.,Epworth HealthCare, Richmond, VIC, Australia
| | | | - Jeremy Grummet
- Department of Surgery, Monash University, Clayton, VIC, Australia.,Epworth HealthCare, Richmond, VIC, Australia
| | | | - Ganes Pranavan
- Department of Medical Oncology, The Canberra Hospital, Canberra, ACT, Australia
| | - Justin S Peters
- Department of Surgery, University of Melbourne, Parkville, VIC, Australia.,Epworth HealthCare, Richmond, VIC, Australia.,Department of Urology, Royal Melbourne Hospital, Parkville, VIC, Australia
| | - Kevin So
- Icon Cancer Centre, Richmond, VIC, Australia
| | - Stella M Gwini
- School of Public Health and Preventive Medicine, Monash University, Clayton, VIC, Australia
| | - Dean P McKenzie
- Epworth HealthCare, Richmond, VIC, Australia.,School of Public Health and Preventive Medicine, Monash University, Clayton, VIC, Australia
| | - Skye Nolan
- Icon Cancer Centre, Richmond, VIC, Australia
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