Volumetric modulated arc therapy (VMAT) craniospinal image-guided radiotherapy and chemotherapy for high-risk medulloblastoma in adults: A case report with analysis of the technique

Introduction: Adult medulloblastoma is a rare disease. Due to the length of the body areas demanding irradiation, medulloblastoma is a challenging malignancy for the development of advanced radiotherapy techniques. Case Report: We describe a volumetric modulated arc therapy (VMAT) technique applied under image-guided radiation therapy (IGRT) for craniospinal irradiation, offered to a patient with high risk medulloblastoma, together with cisplatin/temozolomide chemotherapy. Three areas of irradiation (cranial, thoracic, and lumbar) were defined, with shifting the gaps between them at a weekly basis (two shifts within the three weeks of therapy). The biological equivalent “normalized total dose” (NTD) to the craniospinal axis and the gaps between the three VMAT-treated areas were calculated for α/β-ratio of 2 Gy, and all the data from dose volume histograms (DVHs) are shown. Conclusion: The technique is reliable delivering with safety and accuracy the desirable radiation dose, with biologically and oncologically acceptable dose-deviations within the field-gaps. The tolerance of the radiochemotherapy regimen was excellent.