(0716) Rates of Osteoradionecrosis of Individual Radiotherapy Modalities in the Treatment of Head and Neck Cancer

Introduction: Osteoradionecrosis (ORN) is a serious and morbid complication following radiotherapy for the treatment of head and neck cancer. We aim to describe the rate of osteoradionecrosis based on the modality of radiotherapy (RT) utilized as well as other toxicities such as dermatitis, mucositis, dysphagia, and xerostomia, which, to the best of our knowledge, is the first study to evaluate and summarize these outcomes across a wide range of RTs.

Methods: In this systematic review, an initial search utilizing the databases SCOPUS, Cochran, PubMed, and Google Scholar resulted 655 studies, which was subsequently narrowed to 78 studies over 9 months. Studies that were included provided data on the rate of ORN development and RT toxicities in patients treated with conventional radiotherapy (CRT), 3D-conformal radiotherapy (3D-CRT), intensity-modulated radiotherapy (IMRT), ion (proton or carbon) radiotherapy (IRT), and/or brachytherapy (BT) for head and neck cancer.

Results: Eighty-seven studies were included consisting of 15,628 total patients. The major outcome assessed was the rate of ORN development based on each RT modality. We found rates of ORN development to be 6.3% (45/711) for CRT, 9.9% (59/596) for 3D-CRT, 6.3% (616/9,839) for IMRT, 4.7% (172/3,669) for IRT, and 7.9% (64/813) for BT. As for the secondary outcomes, we found dermatitis in 43.2%, 14.1%, and 4.1% of patients, mucositis in 33.6%, 19.2%, and 9.6% of patients, dysphagia in 31.7% 16.9%, and 11.6% of patients, and xerostomia in 50.3%, 32.5%, and 9.5% of patients treated with CRT, IMRT, and IRT respectively.

Conclusions: This review quantifies the individual rates of ORN and other morbid toxicities for multiple RT modalities. From this study, a direct comparison regarding the rates of these toxicities can be made among these RTs, with 3D-CRT having the highest rate and IRT having the lowest rate for each outcome, providing additional information when selecting a RT for the treatment of head and neck cancer.