![]() Whenever close to the planning target volume (PTV), the eyes, optic nerves, and optic chiasm were delineated. A treatment-planning CT with 3-mm slice thickness and intravenous contrast was acquired in the treatment position and matched with 18F-FDG-PET or MRI in the treatment position to better define the biological target volume and/or clinical target volume (CTV) and OARs.Īccording to the Radiation Therapy Oncology Group (RTOG) guidelines, 23 the following OARs were contoured for the pre-treatment planning: the spinal cord, brain stem, ipsilateral and contralateral parotid glands, oral cavity and larynx (for non-laryngeal cancers). ![]() Immobilization of each patient for simulation and during treatment was achieved with a thermoplastic head and shoulder mask (Civco, Orange City, IA). For this purpose, Christianen et al 22 recently defined guidelines for SWOARs contouring.īased on these findings, the aim of this retrospective analysis is to evaluate potential relationships between planned dose–volume parameters and observed incidence of acute and late dysphagia in patients with HNC treated with IMRT or VMAT, after a recontouring of the PCs according to these recently published guidelines. 19– 21 These studies obtained different results, maybe, owing to a number of methodological issues and to the ambiguous contouring of the PCs. 14– 18 More authors hypothesized that sparing a portion of the constrictor muscles (PCs), not involved by tumour and not at risk of subclinical disease, might reduce dysphagia. Open questions remain for SWOARs, especially with reference to the delineation modalities of the involved structures to the volumes or the dose constraints to be applied. Regarding tolerance of the parotid glands, several studies have suggested significant recovery when the mean dose is inferior to 26 Gy. 4– 8 In comparison with three-dimensional-conformal radiation therapy, several studies have shown that IMRT in HNC treatment reduces overall adverse effects such as xerostomia and dysphagia and thus improves QoL, even when chemotherapy is added. Intensity-modulated radiation therapy (IMRT) and rotational intensity-modulated techniques, including volumetric-modulated arc therapy (VMAT), allow for a better dose conformation to target structures while reducing the dose. However, xerostomia and dysphagia often remain relevant side effects for patients with HNC, compromising their quality of life (QoL), as a consequence of radiation damage to the parotid glands and to the organ at risk (OAR) involved in the swallowing process (SWOARs). Several reports show that radiotherapy (RT) with concomitant chemotherapy or altered fractionation schedules improve tumour control and survival rate. ![]() In the past decade, substantial progress has been made in the treatment of head and neck cancer (HNC). ![]()
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