First Australian experience of treating localised prostate cancer patients with CyberKnife stereotactic radiotherapy: early PSA response, acute toxicity and quality of life

Abstract

IntroductionThis study is to evaluate biochemical response, acute toxicity and health‐related quality‐of‐life (QOL) outcomes among prostate cancer patients following stereotactic body radiation therapy (SBRT) in the first Australian CyberKnife facility.MethodsForty‐five consecutive patients with clinically localised prostate cancer were treated with SBRT using CyberKnife technology and enrolled in this study. Protocol treatment consisted of 36.25 Gy in five fractions. PSA and acute toxicity was assessed at each follow‐up visit and QOL was assessed using the European Organisation for Research and Treatment of Cancer (EORTC) Global Health Status (GHS) C30 and PR25 questionnaires and the Karnofsky Performance Status (KPS). Distance of travel for treatment was recorded.ResultsThe median prostate‐specific antigen (PSA) level declined from the initial value of 6.9 ng/mL to 1.5 ng/mL at 6 months and 0.6 ng/mL at 18 months post‐treatment. Results were similar in patients who did not receive hormone therapy. Acute grade 1 gastrointestinal (GI) and genitourinary (GU) toxicities were found in 11.1% and 24.4% of patients respectively. Acute grade 2 GI and GU toxicities were found in 2.2% and 11.1% of patients respectively. There were no grade 3 and grade 4 toxicities. Mean urinary symptom score was 14.8 at baseline, 17.2 at 6 weeks and 18.3 at 6 months (P > 0.05). Mean bowel symptom score was 2.7 at baseline, 4.2 at 6 weeks and 6.3 at 6 months (P > 0.05). The mean GHS score improved from 81.3 at baseline to 82.4 at 6 weeks, and was 75.6 at 6 months (P > 0.05, not significant). Compared to baseline KPS, there was a significant mean decrease from baseline of 96.7 to 93.3 at the 6‐week follow‐up (P = 0.0043), which then recovered to 94.3 at the 6‐month follow‐up (P = 0.1387).ConclusionsEarly results show promising PSA response. Acute toxicity seemed comparable to results from conventionally fractionated radiotherapy and to international prostate SBRT studies. EORTC PR25 and C30 scores did not reveal any significant change from baseline, and although there was a decrease in KPS, the absolute decrease was small.

Stereotactic Body Radiotherapy for High-Risk Prostate Cancer: A Systematic Review

“…Finally, after exclusion of repeated reports on the same cohort, 18 studies were available for further analyses. Among these, we identified 1 phase III trial [ 23 ], 1 phase II trial [ 24 ], 1 pooled analysis of phase II trials [ 29 ], 4 phase I/II trials [ 26 , 27 , 28 , 38 ], 4 retrospective studies based on prospectively collected data [ 31 , 45 , 55 , 56 ], and 7 retrospective studies [ 34 , 35 , 36 , 39 , 48 , 49 , 50 ]; overall including 651 individual patients. Five additional studies were included because of relevant information, although the patients from the respective cohorts were likely, at least in part, included in repeated reports or pooled analyses; namely 4 retrospective studies based on prospectively collected data [ 30 , 40 , 41 , 47 ] and 1 retrospective study [ 42 ].…”

“…Further evidence is limited to 8 retrospective reports [ 34 , 35 , 36 , 39 , 48 , 49 , 50 , 55 ]. Most of these studies applied a 5-fraction schedule with SBRT doses between 5 × 7 to 5 × 7.5 Gy.…”

“…Similarly, a retrospective study from Taiwan used ADT in 81% for 6 months up to 2 years in a neoadjuvant and concurrent setting [ 49 ]. In an Australian series, 50% of HR patients underwent ADT for 3–6 months [ 55 ]. In addition, a study from South Korea used ADT in their HR cohort for 2 months neoadjuvant and continued then for at least 24 months [ 34 ].…”

Participating in an International Stereotactic Radiotherapy Patient Registry: The Establishment of Data Collection Pathways

“…For example, an internal audit was conducted for all patients with primary hepatocellular carcinoma (HCC) disease treated with CyberKnife between April 2014 and June 2015. A similar audit has been conducted for prostate cancer and has been published [ 20 ]. Internal audits are also conducted every six months for in-house QA and QI activities, investigating data completeness and consistency in data entry techniques across local users.…”

Prostate Stereotactic Body Radiation Therapy With a Focal Simultaneous Integrated Boost: Acute Toxicity and Dosimetry Results From a Prospective Trial

“…A dose of 36.25 Gy in 5 fractions delivered to the whole prostate gland has been associated with acceptable levels of acute and late toxicity in a number of studies,3, 4, 5, 6 including a national phase 2 study, 7 but whether this dose is adequate to achieve long-term biochemical control is unknown, particularly among men with intermediate risk features. On the other hand, higher doses of 50 Gy in 5 fractions to the entire prostate have been associated with excellent rates of 5-year biochemical control, 8 at the potential expense of an increased risk of high-grade toxicity 9 …”