Stereotactic body radiotherapy in the treatment of oligometastatic prostate cancer: early results. Fairleigh Reeves 1 , Patrick Bowden 2 , Anthony Costello 1,2 1 The Royal Melbourne Hospital; 2 Epworth Hospital Richmond, Australia. Introduction
of oligometastatic prostate cancer: early results
Fairleigh Reeves1, Patrick Bowden2, Anthony Costello1,2
1The Royal Melbourne Hospital; 2Epworth Hospital Richmond, Australia
Treatment of metastatic prostate cancer with androgen deprivation therapy (ADT) is effective, but can be associated with debilitating side effects.
Oligometastasis describes a state of limited metastatic capacity (Weichselbaum 2011). This may represent an intermediate disease state that is amenable to aggressive local therapy, allowing deferral of ADT. In practice oligometastasis usually refers to five or fewer metastases. These early metastatic lesions may seed further metastases. Therefore, eradication of oligometastases may alter the progression of disease and potentially offer cure in select cases.
Surgery or radiation therapy are the two treatment options in this setting. Stereotactic body radiotherapy (SBRT) is relatively non-invasive. It delivers an ablative dose of radiotherapy to target tissues, minimising scatter to adjacent structures. Early evidence in other cancers suggests SBRT is a safe and effective treatment for oligometastatic disease (Tree 2013).
To evaluate the effectiveness of SBRTin oligometastatic prostate cancer.
A retrospective review was undertaken of all men with oligometastatic prostate cancer (≤5 sites of metastasis), treated with SBRT by one clinician (PB) from Dec 2007 to Dec 2013.
Outcomes included effectiveness and safety of SBRT. Efficacy was measured by ADT use and biochemical response (PSA). Biochemical failure was defined as two consecutive PSA rises, a single PSA rise >50% of pre-SBRT level, or no absolute reduction in PSA.
Cases studies were also undertaken of two men with complete biochemical response to SBRT.
Results reported are median and range unless otherwise stated.
*Use(d) = current/previous ADT excluding CRPC and neoadjuvant/adjuvant ADT only
Case 1 2013
This promising early data suggests that SBRT has the potential to safely control oligometastatic prostate cancer in the short term, and may delay the need for ADT and its associated side effects. Longer follow-up and prospective controlled trials are warranted.
Case 2 2007
Case 3 2012