Eclipse version 10.0 treatment planning system

The computer tomography (CT) datasets of 10 patients with pathologically confirmed nasopharyngeal squamous cell carcinoma without distant metastasis, treated with chemoradiation at the Cancer Hospital of Shantou University Medical College from January 2013 to June 2014, were identified. The patients (median age 45 years, age range 23–68 years) included 6 females and 4 males. According to the criteria outlined in the seventh edition of the American Joint Committee on Cancer (AJCC) manual (2010), the tumors were in stages T2–T4, N1–N3 and M0, as shown in Table 1. The maximum PTV width was 21.8–25.3 cm and was thus beyond the MLC leaf span. Treatments were planned with patients in the supine position with arms resting at both sides of the body under head-neck-shoulder thermoplastic mask immobilization. The CT datasets, with 3-mm-thick slices gathered from the head to 2 cm below the sternoclavicular joint, were acquired using a 16-slice CT scanner (Philips Brilliance CT Big Bore Oncology Configuration, Cleveland, OH, United States) for all patients. The CT images were transferred to the Eclipse version 10.0 treatment planning system (Varian Medical Systems, Palo Alto, CA, United States) for target-volume and OAR contouring and subsequent treatment planning.

All patients were scanned in supine position with the arms above their heads. A vacuum bag (Medtec Medical, Inc, Buffalo Grove, IL) was used to immobilize the thoracic regions. All the patients received a contrast-enhanced scan with a Big Bore Brilliance CT (Philips Medical Systems, Inc., Cleveland, OH, United States). CT Images were acquired at a 5 mm slice thickness during normal breathing. The CT images were then transferred to the Eclipse version 10.0 treatment planning system (Varian Medical System, Inc., Palo Alto, CA) for target and OAR delineation.