Comparing Simultaneous Integrated Boost and Sequential Boost in Laryngeal and Parotid Gland Head and Neck Cancer Patients

Abstract

Radiation therapy has a key role in treating patients with head and neck cancer. The most often employed radiation therapy technique for head and neck patients, due to the high concentration of vital organs near the tumour, is intensity-modulated radiation therapy (IMRT) either at several fixed gantry angles or as an arc therapy. There are two types of delivery: sequential (SEQ-IMRT) and simultaneous integrated boost (SIB-IMRT) [1]. SEQ-IMRT consists of two sequential plans. In the first plan the target structure is the low risk planning target volume (PTV-LR) and then, with a second plan, a boost dose is applied only to the high risk planning target volume (PTV-HR). The SIB-IMRT technique consists of a single plan with different radiation doses applied appropriately to the PTV-HR and PTV-LR [2]. Both techniques are wieldy used in practice. The aim of this study is to make a treatment planning comparison of both techniques by comparing the doses received by the organs at risk (OARs), keeping the target coverage radiobiologically equal [3]. For that purpose, two groups of patients were evaluated, for a total of thirty patients. The first group comprises of 15 patients with inoperable advanced stage laryngeal cancer, while the second group includes 15 parotid gland cancer post-op patients. In the laryngeal group, definitive radiotherapy was the main treatment, while in the parotid group radiotherapy was added as adjuvant postoperative treatment. The main side effect during the course of radiotherapy is mucositis, which is also a limiting factor for the completion of the radiotherapy treatment. A second side effect after the end of treatment is xerostomia, which affects the long term oral health of patients.