CyberKnife stereotactic radiosurgery and stereotactic ablative radiation therapy of patients with prostate cancer bone metastases.

Abstract

The aim of the study was to evaluate the effectiveness and toxicity of CyberKnife (CK) stereotactic radiosurgery (SRS) and stereotactic ablative radiation therapy (SABR) of patients with prostate cancer bone metastases. Analysis of prognostic and predictive factors was also performed.Material consisted of 51 patients with 71 bone oligometastases treated using CK SRS/SABR. In half of the patients single lesion was treated, in half 2-5 lesions. Median PSA concentration at the time of metastasis detection was 5.75 ng/ml. Total dose of 6-45Gy (median 20) was delivered with 1-5 fractions of 6-15 Gy (median 9). Biologic equivalent dose (BED) (α/ β=1.6) over 100 Gy was delivered to 45 lesions (63%) in 38 patients (75%).In statistical analysis Kaplan-Meier method, log-rank test and the Cox proportional hazard model were used. One-, two-and three-year overall survival (OS) was 90%, 76% and 70%, respectively. All patients having PSA concentration lower that 1 ng/ml at last control lived at least three years. One-, two-and three-year local control (LC) was 97%, 70% and 30%. Patients with PSA below 20 ng/ml at the time of metastasis detection had better local control of lesions and lower PSA at the last control. Median of PSA concentration after CK based SRS/SABR remains stable during first 12 months of follow-up, dropped during the next months and at last control was comparable to initial level. Median PSA at last control in patients without disease progression was 1.67ng/ml and 20 patients had PSA below 1.0ng/ml. At the last control 59% of patients had no other metastases. Rapid pain decrease was observed in analysed group and during each control about 90% of patients had pain relief. No major toxicity was observed, 3 patients suffered from fracture of irradiated bone. SRS/SABR of prostate cancer bone oligometastases provides good LC of lesions, excellent pain control without additional toxicity. Patients with PSA concentration below 20ng/ml at the time of metastasis detection have better LC and PSA concentration response.

Use of stereotactic body radiation therapy for oligometastatic recurrent prostate cancer: A systematic review

“…The exclusion reasons with references are listed in Data S2. Finally, 14 articles were selected for data extraction and subsequent qualitative synthesis.…”

“…One randomized controlled trial was found, but it did not meet all the eligibility criteria, so it was not included in the qualitative analysis . Thirteen articles were single‐arm case series/cohort studies, and one case–control series, with five (36%) prospective and nine (64%) retrospective researches . Median follow‐up period varied from 10.2 to 36.6 months (Table ).…”

“…Toxicity was assessed according to the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer (RTOG/EORTC) criteria in six (43%) studies and the Common Terminology Criteria for Adverse Events (CTCAE) in five (35%) others . Three (21%) articles did not describe the criteria adopted …”

“…The number of publications on the topic is rapidly increasing. Nine of the articles included were published from 2016 onwards . There are at least three ongoing randomized trials.…”

“…The exclusion reasons with references are listed in Data S2. Finally, 14 articles [25][26][27][28][29][30][31][32][33][34][35][36][37][38] were selected for data extraction and subsequent qualitative synthesis. Figure 1 details the process of identification, inclusion and exclusion of studies.…”