RESUMO
This document is the report of a task group of the AAPM and has been prepared primarily to advise medical physicists involved in the external-beam radiation therapy of patients with thoracic, abdominal, and pelvic tumors affected by respiratory motion. This report describes the magnitude of respiratory motion, discusses radiotherapy specific problems caused by respiratory motion, explains techniques that explicitly manage respiratory motion during radiotherapy and gives recommendations in the application of these techniques for patient care, including quality assurance (QA) guidelines for these devices and their use with conformal and intensity modulated radiotherapy. The technologies covered by this report are motion-encompassing methods, respiratory gated techniques, breath-hold techniques, forced shallow-breathing methods, and respiration-synchronized techniques. The main outcome of this report is a clinical process guide for managing respiratory motion. Included in this guide is the recommendation that tumor motion should be measured (when possible) for each patient for whom respiratory motion is a concern. If target motion is greater than 5 mm, a method of respiratory motion management is available, and if the patient can tolerate the procedure, respiratory motion management technology is appropriate. Respiratory motion management is also appropriate when the procedure will increase normal tissue sparing. Respiratory motion management involves further resources, education and the development of and adherence to QA procedures.
Assuntos
Neoplasias/radioterapia , Radioterapia (Especialidade)/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia de Intensidade Modulada/métodos , Respiração , Guias como Assunto , Humanos , Movimento (Física) , Neoplasias/patologia , Controle de Qualidade , Radiometria , Dosagem Radioterapêutica , Radioterapia Assistida por Computador , Fatores de Tempo , Tomografia Computadorizada por Raios X/métodosRESUMO
PURPOSE: To determine the feasibility of and patient outcomes using customized high-dose-rate (HDR) brachytherapy to boost the nasopharynx after external beam radiation therapy (EBRT) in patients with carcinoma of the nasopharynx. METHODS AND MATERIALS: Patients with nonmetastatic squamous cell carcinoma of the nasopharynx were treated using EBRT followed by a HDR brachytherapy boost delivered via customized catheters in a noninvasive, accurate, and reproducible method under direct fiber-optic visualization. Local control (LC), disease-free survival (DFS), and overall survival (OS) were analyzed. We also measured the change in maximum oral aperture as an indication of temporomandibular joint dysfunction. RESULTS: Between March 1996 and July 2003, we treated 38 patients with this customized brachytherapy method. The procedure was well tolerated without any incidents of soft-tissue or bone necrosis and with minimal decrease of oral aperture. Median follow-up time was 47 months (range, 2-84 months); 35 patients had at least 1 year of follow-up. The 5-year actuarial rate of LC, DFS, and OS were 96.0%, 81.4%, and 92.7%, respectively. CONCLUSIONS: The treatment has been well tolerated by all patients. The combination of conformal EBRT with our customized HDR brachytherapy boost has resulted in excellent local control to date, while minimizing temporomandibular joint dysfunction.