Stereotactic body radiotherapy in the management of hepatocellular carcinoma: An Australian multi-institutional patterns of practice review.

INTRODUCTION: Stereotactic body radiotherapy (SBRT) is an emerging, therapeutic option in the management of hepatocellular carcinoma (HCC). A multicentre Liver Ablative Stereotactic Radiation (LASR) database was established to provide a collaborative platform for Australian institutions to define the practice of liver SBRT for HCC. This study explores the patterns of SBRT practice amongst Australian institutions. METHODS: This was a multi-institutional retrospective study of patients treated with SBRT for HCC at 10 institutions between January 2013 and December 2019. Patients' demographics, disease characteristics and SBRT details were evaluated. RESULTS: Three hundred and seventeen patients were evaluated with a median age of 67 years (range, 32-90). Liver cirrhosis was present in 88.6%, baseline Child-Pugh score was A5/6 in 85.1% and B7/8 in 13.2%. Median size of HCC treated was 30 mm (range, 10-280). 63.1% had early-stage disease (Barcelona clinic liver cancer (BCLC) stage 0/A) and 36% had intermediate/advanced-stage disease (BCLC B/C). In 2013/2014, six courses of SBRT were delivered, increasing to 108 in 2019. SBRT was prescribed in five fractions for 71.3% of the cohort. The most common dose fractionation schedule was 40 Gy in five fractions (24.3%). Median biologically effective dose (BED10 ) delivered was 85.5 Gy for early-stage and 60 Gy for intermediate/advanced disease, respectively. The most common prescription range was 100-120 Gy BED10 (32.8%). CONCLUSION: SBRT utilisation for HCC is increasing in Australia. There was wide variation in size of tumours and disease stages treated, and prescription patterns. Uniform reporting of clinical and dosimetric details are important in refining the role of liver SBRT.

Survival of patients with melanoma brain metastasis treated with stereotactic radiosurgery and active systemic drug therapies.

INTRODUCTION: With new systemic therapies demonstrating activity in melanoma brain metastasis, most of the previously reported stereotactic radiosurgery (SRS) data are superseded. In this study, we report the outcomes (overall survival [OS] and brain control [BC]) and identify factors that associate with such outcomes in the era of modern systemic therapy. METHOD: A total of 108 patients treated with SRS from 2010 to 2015 were included. Systemic treatment use within 6 weeks of SRS was noted. OS was defined as time from SRS to death or last follow-up, and BC was defined as absence of any active intracranial disease during follow-up. Univariate and multivariate Cox proportional hazard analyses were performed on clinico-pathological prognostic features associated with OS and BC. RESULTS: The median age was 64.3 years, and the median follow-up was 8.6 months. Seventy-nine (73.1%) patients received systemic treatment. The median OS were as follows: anti-CTLA4 - 7.5 months (95% CI: 4.4-15.6), anti-PD1 - 20.4 months (95% CI: 8.8 - N/A) and BRAF inhibitor (BRAFi) ± MEK inhibitor (MEKi) - 17.8 months (95% CI: 11.8 - N/A). Median BC was as follows: anti-CTLA4 - 7.5 months (95% CI: 4.0-15.6), anti-PD1 - 12.7 months (95% CI: 5.5 - N/A) and BRAFi ± MEKi - 12.7 months (95% CI: 8.3-18.5). In multivariate analysis, age and type of systemic therapy were strongly associated with OS. Age, Eastern Cooperative Oncology Group performance status, Graded Prognostic Assessment (GPA) score, and presence of symptoms were associated with BC. CONCLUSIONS: Favourable outcomes are seen in patients treated with SRS and with the best survival seen in patients treated with anti-PD1. Known independent prognostic factors for survival such as age and performance status and GPA score remain relevant in this setting.

78Gy with Fiducial Marker Image-Guided Radiotherapy in Prostate Cancer: Single Center Analysis of 301 Patients.

AIM: In prostate cancer, fiducial marker image-guided radiotherapy (FMIGRT) allows correction of setup errors and interfraction physiological motion resulting in improved accuracy of target and sparing of at risk organs. We aim to report outcomes and toxicities observed in patients treated with dose escalation to 78Gy with FMIGRT in our center. METHODS AND MATERIALS: Retrospective review of consecutive patients with histologically confirmed T1-4N0M0 localized prostate cancer treated with dose escalation to 78Gy with FMIGRT in our center. All patients had 3-D conformal radiotherapy. Duration of androgen deprivation therapy use was tailored to risk group. Toxicity was scored according to CTCAE.v04. Kaplan-Meier analysis was performed for freedom from biochemical failure (FFBF), prostate cancer-specific survival and overall survival. RESULTS: Median follow-up was 48.6 months. Median duration of androgen deprivation therapy was 6 and 23 months in the intermediate- and high-risk group, respectively. FFBF at 5 years was 88.8%. FFBFs when stratified to risk groups were 100% for low risk, 88.9% for low-intermediate risk, 89.9% for high-intermediate risk and 85.4% for high risk, respectively. Acute severe toxicity (grade≥3) rate for both genitourinary (GU) and gastrointestinal (GI) was 1%. Late moderate-to-severe toxicity (grade≥2) rates for GU and GI were 15% and 17%, respectively, with severe (grade≥3) toxicity rate for GU and GI at 2% and 3%, respectively. CONCLUSION: Dose escalation to 78Gy with FMIGRT in our series achieved good FFBF at 5 years with low acute and late toxicity rates. These results provide a good comparator cohort to our current use of image-guided intensity modulated radiotherapy.

Hybrid (CT/MRI based) vs. MRI only based image-guided brachytherapy in cervical cancer: Dosimetry comparisons and clinical outcome.

PURPOSE: Limited access to MRI has restricted implementation of MRI-based image-guided brachytherapy (IGBT) in line with GEC-ESTRO guidelines in many centers. This work reports our experience using an alternative CT/MRI based (hybrid) approach for IGBT, dosimetry comparisons, and its impact on long-term clinical outcome and major toxicity. METHODS AND MATERIALS: Seventy-six patients diagnosed with locally advanced cervical cancer between May 2008 and May 2012 treated with IGBT were analyzed. The hybrid approach is the default IGBT approach during this study period. Forty-nine had hybrid approach and 27 patients had "3-fraction conformal MRI" approach (17 within EMBRACE study). Treatment consisted of 48 Gy in 24 fractions of conformally planned external beam radiotherapy with weekly cisplatin followed by three weekly fractions of brachytherapy to high-risk clinical target volume (HR-CTV). All patients have a prebrachytherapy MRI 4 days before treatment and with the applicators in place on Fraction 1. MRI only or CT is used for subsequent fractions. Using image registration techniques and the assumption that the HR-CTV is fixed with respect to the applicator, the HR-CTV from MRI at Fraction 1 is transferred onto subsequent fraction CT image sets for the hybrid approach. RESULTS: Median follow-up was 41 months (range, 23-71 months). Excellent 3-year local control, overall progression-free survival, and overall survival of 92.6%, 78.8%, and 77.7% were seen with the hybrid approach and 92.2%, 66.3%, and 69.6% with a 3-fraction conformal MRI approach, respectively. Dosimetry achieved and late toxicity rates were comparable in the two groups. CONCLUSIONS: Hybrid IGBT in locally advanced cervical cancer offers an alternative approach when access to MRI restricts implementation of IGBT.