Superior outcomes of Volumetric Modulated Arc Therapy (VMAT) in the palliation of skull metastases of multiple myeloma: a case report

Palliative radiotherapy (RT) is often given to symptomatic sites of multiple myeloma (MM). Three-dimensional conformal radiotherapy (3DCRT) is often the main modality due its efficiency but it may involve irradiation volumes which include organs at risk (OARs). A case of end-stage MM with innumerable skull lesions was treated with volumetric modulated arc therapy (VMAT) which demonstrated superior conformity compared to a 3DCRT plan. VMAT planning yielded an 88% dose reduction to the hippocampi, 60% dose reduction to the brain yet equivalent dose homogeneity to the skull target. Treatment with 15Gy in five fractions gave significant almost complete symptom resolution with no adverse OAR related complications at 4 weeks.As the life expectancy of MM patients and other cancers increases with better systemic therapy, there will be a greater chance of experiencing late effects of RT in OARs. This case supports the notion that perhaps VMAT could be considered in some cases of palliative RT.