Dosimetric justification for the use of volumetric modulated arc therapy in head and neck cancer—A systematic review of the literature

INTRODUCTION: Radiotherapy for head and neck cancer (HNC) has evolved rapidly in the past decades from conformal three‐dimensional technique (3D‐CRT) to intensity‐modulated radiotherapy (IMRT) and volumetric‐modulated arc therapy (VMAT). This paper presents a dosimetric comparative study between VMAT and IMRT delivery based on current literature, while also presenting the potential challenges encountered with volumetric arc therapy. METHODS: A systematic search of the scientific literature was conducted within Medline/Pubmed databases. A number of 13 papers fulfilled the search criteria which was based on the main objective to evaluate dosimetric characteristics of comparative treatment delivery with VMAT vs IMRT in HNC. RESULTS: Overall, from a dosimetric perspective, dose delivery via VMAT and IMRT present comparable results. Beside the delivery technique, target volume coverage also depends on the planner's expertise as well as the employed planning algorithm. At times, the superiority of VMAT emerges from the improved sparing of normal tissue, reduction of monitor units (MU) and of treatment delivery time. Similar to IMRT, one of the most important challenges of VMAT is the risk of developing secondary cancer due to the higher number of MUs compared to 3D‐CRT. CONCLUSIONS: Based on the comparative results with the more established IMRT, VMAT in HNC can be safely delivered either as a single treatment or combined with other techniques.