HyperArcTM volumetric modulated arc therapy for hypopharyngeal cancer with solitary recurrence in the cervical vertebra: A case report and literature review.

Abstract

It is difficult to reirradiate head and neck cancers because of the toxicity from previous radiation dose delivery. Conventional volumetric modulated arc therapy (VMAT) and intensity-modulated radiation therapy often have poor target coverage. The new HyperArcTM VMAT (HA-VMAT) planning approach reportedly has better target coverage, higher conformity, and can spare normal organs compared to conventional VMAT; however, research on recurrent head and neck cancers is limited. Here, we report the clinical outcomes of HA-VMAT for previously irradiated hypopharyngeal cancer with solitary recurrence in the first cervical vertebra (C1). A 52-year-old Asian male was diagnosed with a hypopharyngeal cancer. The patient received concurrent chemoradiotherapy with a radiation dose of 70 Gy in 33 fractions and achieved complete clinical response. Two years later, solitary recurrence was observed in the C1 vertebra. Solitary recurrence in the C1 vertebra. Owing to concerns regarding the toxicity to adjacent organs, we decided to use HA-VMAT to achieve better tumor coverage and critical organ sparing. Tumor regression was observed on the imaging. At 9 months follow-up, the patient was disease-free and had no late toxicities. This is the first report regarding the clinical outcomes of HA-VMAT for previously irradiated hypopharyngeal cancer with solitary recurrence over the C1 vertebra. HA-VMAT achieves highly conformal dose distribution and excellent sparing of critical organs. There was a favorable initial clinical response with no toxicity. Long-term follow-up is essential in such cases.