Carbon ion radiotherapy of hepatocellular carcinoma provides excellent local control: The prospective phase I PROMETHEUS trial.

Background & Aims: Inoperable hepatocellular carcinoma (HCC) can be treated by stereotactic body radiotherapy. However, carbon ion radiotherapy (CIRT) is more effective for sparing non-tumorous liver. High linear energy transfer could promote therapy efficacy. Japanese and Chinese studies on hypofractionated CIRT have yielded excellent results. Because of different radiobiological models and the different etiological spectrum of HCC, applicability of these results to European cohorts and centers remains questionable. The aim of this prospective study was to assess safety and efficacy and to determine the optimal dose of CIRT with active raster scanning based on the local effect model (LEM) I. Methods: CIRT was performed every other day in four fractions with relative biological effectiveness (RBE)-weighted fraction doses of 8.1-10.5 Gy (total doses 32.4-42.0 Gy [RBE]). Dose escalation was performed in five dose levels with at least three patients each. The primary endpoint was acute toxicity after 4 weeks. Results: Twenty patients received CIRT (median age 74.7 years, n = 16 with liver cirrhosis, Child-Pugh scores [CP] A5 [n = 10], A6 [n = 4], B8 [n = 1], and B9 [n = 1]). Median follow up was 23 months. No dose-limiting toxicities and no toxicities exceeding grade II occurred, except one grade III gamma-glutamyltransferase elevation 12 months after CIRT, synchronous to out-of-field hepatic progression. During 12 months after CIRT, no CP elevation occurred. The highest dose level could be applied safely. No local recurrence developed during follow up. The objective response rate was 80%. Median overall survival was 30.8 months (1/2/3 years: 75%/64%/22%). Median progression-free survival was 20.9 months (1/2/3 years: 59%/43%/43%). Intrahepatic progression outside of the CIRT target volume was the most frequent pattern of progression. Conclusions: CIRT of HCC yields excellent local control without dose-limiting toxicity. Impact and implications: To date, safety and efficacy of carbon ion radiotherapy for hepatocellular carcinoma have only been evaluated prospectively in Japanese and Chinese studies. The optimal dose and fractionation when using the local effect model for radiotherapy planning are unknown. The results are of particular interest for European and American particle therapy centers, but also of relevance for all specialists involved in the treatment and care of patients with hepatocellular carcinoma, as we present the first prospective data on carbon ion radiotherapy in hepatocellular carcinoma outside of Asia. The excellent local control should encourage further use of carbon ion radiotherapy for hepatocellular carcinoma and design of randomized controlled trials. Clinical Trials Registration: The study is registered at ClinicalTrials.gov (NCT01167374).

High-resolution FLAIR MRI at 7 Tesla for treatment planning in glioblastoma patients.

Ultra-high field MRI is an emerging technique promising high-resolution images for radiotherapy planning. We compared a 7 Tesla FLAIR sequence with clinical FLAIR imaging at 3 Tesla in glioblastoma patients before radiotherapy. High-resolution 7 Tesla FLAIR imaging may enhance the depiction of organs at risk and possibly modify target volumes.

Metformin influences progression in diabetic glioblastoma patients.

PURPOSE: Changes in metabolism, including high glucose serum levels, seem to influence the initiation of malignancy as well as recurrence. Therefore, limiting the energy supply in tumor cells with the antidiabetic drug metformin might be a useful approach to inhibit glioma cell progression. However, little is known about the effects of endocrine disorders (e.g., diabetes mellitus, corticosteroid therapy, and metformin therapy) on progression and survival in primary glioblastoma patients. PATIENTS AND METHODS: Between 2006 and 2013, 276 patients with primary glioblastoma underwent radiation therapy at Heidelberg University Hospital and German Cancer Research Center. Clinical records as well as pretherapeutic and follow-up magnetic resonance (MR) images were assessed. Forty patients (14.5 %) were identified with a pretherapeutic history of diabetes, and 20 (50 %) of them were treated with metformin. Survival and correlations were calculated using t-test and log-rank, univariate and multivariate Cox proportional hazards ratio analyses. RESULTS: Persistent mild and excessive hyperglycemia were correlated with decreased survival. Corticosteroid therapy was associated with decreased progression-free and overall survival in the multivariate analysis. No negative influence of diabetes on progression and survival could be detected. Interestingly, diabetic patients with metformin therapy demonstrated prolonged progression-free intervals. CONCLUSION: Corticosteroid therapy and hyperglycemia were strongly associated with impaired survival rates and serves as negative prognostic factors. Diabetes did not influence survival. Interestingly, our findings showed an association of metformin therapy and prolonged progression-free survival in glioblastoma patients with diabetes and therefore serve as a foundation for further preclinical and clinical investigations.