Dose prescription for stereotactic body radiotherapy: general and organ-specific consensus statement from the DEGRO/DGMP Working Group Stereotactic Radiotherapy and Radiosurgery.

PURPOSE AND OBJECTIVE: To develop expert consensus statements on multiparametric dose prescriptions for stereotactic body radiotherapy (SBRT) aligning with ICRU report 91. These statements serve as a foundational step towards harmonizing current SBRT practices and refining dose prescription and documentation requirements for clinical trial designs. MATERIALS AND METHODS: Based on the results of a literature review by the working group, a two-tier Delphi consensus process was conducted among 24 physicians and physics experts from three European countries. The degree of consensus was predefined for overarching (OA) and organ-specific (OS) statements (≥ 80%, 60-79%, < 60% for high, intermediate, and poor consensus, respectively). Post-first round statements were refined in a live discussion for the second round of the Delphi process. RESULTS: Experts consented on a total of 14 OA and 17 OS statements regarding SBRT of primary and secondary lung, liver, pancreatic, adrenal, and kidney tumors regarding dose prescription, target coverage, and organ at risk dose limitations. Degree of consent was ≥ 80% in 79% and 41% of OA and OS statements, respectively, with higher consensus for lung compared to the upper abdomen. In round 2, the degree of consent was ≥ 80 to 100% for OA and 88% in OS statements. No consensus was reached for dose escalation to liver metastases after chemotherapy (47%) or single-fraction SBRT for kidney primaries (13%). In round 2, no statement had 60-79% consensus. CONCLUSION: In 29 of 31 statements a high consensus was achieved after a two-tier Delphi process and one statement (kidney) was clearly refused. The Delphi process was able to achieve a high degree of consensus for SBRT dose prescription. In summary, clear recommendations for both OA and OS could be defined. This contributes significantly to harmonization of SBRT practice and facilitates dose prescription and reporting in clinical trials investigating SBRT.

Staging Evaluation and Response Criteria Harmonization (SEARCH) for Childhood, Adolescent and Young Adult Hodgkin Lymphoma (CAYAHL): Methodology statement.

International harmonization of staging evaluation and response criteria is needed for childhood, adolescence, and young adulthood Hodgkin lymphoma. Two Hodgkin lymphoma protocols from cooperative trials in Europe and North America were compared for areas in need of harmonization, and an evidence-based approach is currently underway to harmonize staging and response evaluations with a goal to enhance comparisons, expedite identification of effective therapies, and aid in the approval process for new agents by regulatory agencies.

Stereotactic body radiotherapy for centrally located stage I NSCLC: a multicenter analysis.

PURPOSE: The purpose of this work is to analyze patterns of care and outcome after stereotactic body radiotherapy (SBRT) for centrally located, early-stage, non-small cell lung cancer (NSCLC) and to address the question of potential risk for increased toxicity in this entity. METHODS AND MATERIALS: A total of 90 patients with centrally located NSCLC were identified among 613 cases in a database of 13 German and Austrian academic radiotherapy centers. The outcome of centrally located NSCLC was compared to that of cases with peripheral tumor location from the same database. RESULTS: Patients with central tumors most commonly presented with UICC stage IB (50 %), while the majority of peripheral lesions were stage IA (56 %). Average tumor diameters were 3.3 cm (central) and 2.8 cm (peripheral). Staging PET/CT was available for 73 and 74 % of peripheral and central tumors, respectively. Biopsy was performed in 84 % (peripheral) and 88 % (central) of cases. Doses varied significantly between central and peripheral lesions with a median BED10 of 72 Gy and 84 Gy, respectively (p < 0.001). Fractionation differed as well with medians of 5 (central) and 3 (peripheral) fractions (p < 0.001). In the Kaplan-Meier analysis, 3-year actuarial overall survival was 29 % (central) and 51 % (peripheral; p = 0.004) and freedom from local progression was 52 % (central) and 84 % (peripheral; p < 0.001). Toxicity after treatment of central tumors was low with no grade III/IV and one grade V event. Mortality rates were 0 and 1 % after 30 and 60 days, respectively. CONCLUSION: Local tumor control in patients treated with SBRT for centrally located, early-stage NSCLC was favorable, provided ablative radiation doses were prescribed. This was, however, not the case in the majority of patients, possibly due to concerns about treatment-related toxicity. Reported toxicity was low, but prospective trials are needed to resolve the existing uncertainties and to establish safe high-dose regimens for this cohort of patients.