Background & Aims: Early-stage HCC can be treated with thermal ablation or stereotactic body radiation therapy (SBRT). We retrospectively compared local progression, mortality, and toxicity among patients with HCC treated with ablation or SBRT in a multicenter, US cohort. Approach & Results: We included adult patients with treatment-naïve HCC lesions without vascular invasion treated with thermal ablation or SBRT per individual physician or institutional preference from January 2012 to December 2018. Outcomes included local progression after a 3-month landmark period assessed at the lesion level and overall survival at the patient level. Inverse probability of treatment weighting was used to account for imbalances in treatment groups. The Cox proportional hazard modeling was used to compare progression and overall survival, and logistic regression was used for toxicity. There were 642 patients with 786 lesions (median size: 2.1 cm) treated with ablation or SBRT. In adjusted analyses, SBRT was associated with a reduced risk of local progression compared to ablation (aHR 0.30, 95% CI: 0.15–0.60). However, SBRT-treated patients had an increased risk of liver dysfunction at 3 months (absolute difference 5.5%, aOR 2.31, 95% CI: 1.13–4.73) and death (aHR 2.04, 95% CI: 1.44–2.88, p < 0.0001). Conclusions: In this multicenter study of patients with HCC, SBRT was associated with a lower risk of local progression compared to thermal ablation but higher all-cause mortality. Survival differences may be attributable to residual confounding, patient selection, or downstream treatments. These retrospective real-world data help guide treatment decisions while demonstrating the need for a prospective clinical trial.
Neoadjuvant Therapy Regimens for Hilar Cholangiocarcinoma Before Liver Transplant
Objectives: Patients with unresectable hilar cholangiocarcinoma (hCCA) may be eligible for curative treatment through liver transplantation (LT). Neoadjuvant protocols often include radiotherapy (RT), however, there is no standard RT approach. The purpose of this study is to characterize practice patterns of RT use before transplantation for hCCA. Methods: A survey was administered to radiation oncologists practicing at LT centers identified through the U.S. Organ Procurement and Transplant Network and the International Cholangiocarcinoma Research Network. The survey consisted of 13 questions regarding RT details as well as approaches to systemic therapy. For cross-regimen comparison, the cumulative RT tumor dose was standardized using the EQD2 method. Results: Twenty-three centers utilizing neoadjuvant therapy for hCCA were identified. Most respondents (96%) use both chemotherapy and RT as part of their protocol. Elective nodal volumes commonly included the portal vein lymph nodes (91%) and celiac artery lymph nodes (70%). After an initial 45 Gy plan, a wide range of sequential boost regimens was used. The median cumulative dose including boosts to the gross disease was 58 Gy (EQD2) with a wide range of 40 to 110 Gy. Five (22%) include brachytherapy as part of their treatment plan. The majority (96%) used concurrent chemotherapy with fluoropyrimidines. Conclusions: These results suggest significant variability of neoadjuvant RT use for hCCA before LT. A wide range of doses and fractionation schemes are utilized with cumulative doses ranging from 40 to 110 Gy (EQD2). A further study evaluating the efficacy and toxicity of these various approaches is warranted to better inform best practices.
Multi‐institutional experience of stereotactic body radiotherapy for large (≥5 centimeters) non–small cell lung tumors