Outcomes and Imaging Analysis in Hepatocellular Carcinoma Treated With Stereotactic Body Radiation Therapy.

PURPOSE: Although arterial phase enhancement is commonly used to evaluate treatment response for hepatocellular carcinoma, it may not accurately describe response for lesions treated with stereotactic body radiation therapy (SBRT). We aimed to describe the post-SBRT imaging findings to better inform the optimal timing of salvage therapy after SBRT. METHODS AND MATERIALS: We retrospectively reviewed patients with hepatocellular carcinoma treated with SBRT from 2006 to 2021 at a single institution with available imaging showing lesions with characteristic arterial enhancement and portal venous washout. Patients were then stratified into 3 groups based on treatment: (1) concurrent SBRT and transarterial chemoembolization, (2) SBRT only, and (3) SBRT followed by early salvage therapy due to persistent enhancement. Overall survival was analyzed with the Kaplan-Meier method, and cumulative incidences were calculated with competing risk analysis. RESULTS: We included 82 lesions in 73 patients. The median follow-up time was 22.3 months (range, 2.2-88.1 months). The median time to overall survival was 43.7 months (95% confidence interval, 28.1-57.6 months) and median progression-free survival was 10.5 months (95% confidence interval, 7.2-14.0 months). There were 10 (12.2%) lesions that experienced local progression and there was no difference in rates of local progression between the 3 groups (P = .32). In the SBRT-only group, the median time to resolution of arterial enhancement and washout was 5.3 months (range, 1.6-23.7 months). At 3, 6, 9, and 12 months, 82%, 41%, 13%, and 8% of lesions, respectively, continued to show arterial hyperenhancement. CONCLUSIONS: Tumors treated with SBRT may continue to exhibit persistence of arterial hyperenhancement. Without an increase in size of enhancement, continued surveillance may be appropriate for these patients.

Rectosigmoid Cancer-Rectal Cancer or Sigmoid Cancer?

OBJECTIVES: We aimed to determine the optimal treatment for patients with locally advanced rectosigmoid cancers, and to determine whether this can be guided by distance from anal verge (AV) and/or anatomic landmarks such as the sacral promontory and peritoneal reflection (PR). MATERIALS AND METHODS: We retrospectively reviewed patients with T3-T4 and/or node-positive rectosigmoid cancers who underwent surgery from 2006 to 2018 with available pelvic imaging. We included tumors at 9 to 20 cm from the AV on either staging imaging, or colonoscopy. Patients were stratified into those who received neoadjuvant therapy, and those who underwent upfront surgery. Comparisons of characteristics were performed using χ 2 test and Fischer exact test. Locoregional failure (LRF) and overall survival were compared using Cox regressions and Kaplan-Meier analysis. RESULTS: One hundred sixty-one patients were included. Ninety-seven patients had neoadjuvant therapy, and 64 patients had upfront surgery. Median follow-up time was 45.1 months. Patients who had neoadjuvant therapy had tumors that were higher cT stage ( P <0.01) with more positive/close circumferential resection margins seen on imaging by radiologists (28.9% vs. 1.6% , P =0.015). The 2-year rate of LRF, distant metastases, or overall survival was not significantly different between the 2 groups. None of 15 patients with tumors below the PR treated with neoadjuvant therapy had LRF, but 1 (25%) of 4 patients with tumors below the PR treated with adjuvant therapy experienced LRF ( P =0.05). CONCLUSIONS: Patients with tumors below the PR may benefit more from neoadjuvant therapy. The PR on imaging may be a reliable landmark in addition to the distance from the AV to determine the most appropriate treatment option.