Improving on whole-brain radiotherapy in patients with large brain metastases: A planning study to support the AROMA clinical trial. (May 2022)

• Record Type: Journal Article
• Authors: Chen, Jiarong; Sinclair, Georges; Rozati, Hamoun; Hill, Laurence; Pakzad-Shahabi, Lillie; Wang, James; Calvez, Kerlann Le; Paddick, Ian; Williams, Matt
• Is Part Of: Radiotherapy and oncology. Volume 170(2022)
• Page Start: 176
• Page End: 183
• Publication Date: 2022-05
• Subjects: CITV cumulative intracranial tumour volume -- DE-iPTV dose-escalated inner planning target volumes -- ds-GPA disease-specific graded prognostic assessment -- DVHs dose-volume histograms -- GTV gross tumour volume -- HD MLC high-definition multileaf collimator -- HR Hazard Ratio -- PIV 50% half the prescription isodose -- HS-WBRT hippocampal-sparing whole brain radiotherapy -- LC local control -- OARs organs at risks -- OS overall survival -- PTV planning target volume -- SRS stereotactic radiosurgery -- TV target volume -- VMAT volumetric modulated arc therapy -- WBRT whole brain radiotherapy; Brain metastases -- WBRT -- VMAT -- Dose-escalated planning -- Local control; Oncology -- Periodicals; Radiotherapy -- Periodicals; Tumors -- Periodicals; Medical Oncology -- Periodicals; Neoplasms -- radiotherapy -- Periodicals; Radiotherapy -- Periodicals; Radiothérapie -- Périodiques; Cancérologie -- Périodiques; Tumeurs -- Périodiques; Electronic journals; 616.9940642
• DOI: 10.1016/j.radonc.2022.02.011
• Languages: English
• ISSNs: 0167-8140

Abstract

Graphical abstract: Highlights: Radiotherapy for 1 to 10 brain metastases and at least one lesion larger than 15 cm 3 . Comparison of VMAT plans with WBRT and HS-WBRT. Development of a novel dose-escalated internal PTV model with VMAT. Performance of dose distributions within the tumours and OARs. Abstract: Purpose: To develop a novel dose-escalated volumetric modulated arc therapy (VMAT) strategy for patients with single or multiple large brain metastases which can deliver a higher dose to individual lesions for better local control (LC), and to compare dosimetry between whole brain radiotherapy (WBRT), hippocampal-sparing whole brain radiotherapy (HS-WBRT) and different VMAT-based focal radiotherapy approaches. Methods and materials: We identified 20 patients with one to ten brain metastases and at least one lesion larger than 15 cm 3 who had received WBRT as part of routine care. For each patient, we designed and evaluated five radiotherapy treatment plans, including WBRT, HS-WBRT and three VMAT dosing models. A dose of 20 Gy in 5 fractions was prescribed to the whole brain or target volumes depending on the plan, with higher doses to smaller lesions and dose-escalated inner planning target volumes (DE-iPTV) in VMAT plans, respectively. Treatment plans were evaluated using the efficiency index, mean dose and D0.1 cc to the target volumes and organs at risk. Results: Compared with WBRT, VMAT plans achieved a significantly more efficient dose distribution in brain lesions, especially with our DE-iPTV model, while minimising the dose to the normal brain and other organs at risks (OARs) ( p < 0.05). Conclusions: VMAT plans obtained higher doses to brain metastases and minimised doses to OARs. Dose-escalated VMAT for larger lesions allows higher radiotherapy doses to be delivered to larger lesions while maintaining safe doses to OARs.