Clinac ix

The teeth in the experimental group were fixed to wax the patterns (7 teeth fixed to each wax pattern) and covered with a gauze patch impregnated with artificial saliva and then placed in the center of a styrofoam container filled with partially crushed rice. Five different styrofoam containers were prepared (ICP-OES-primary teeth, ICP-OES-permanent teeth, Vickers-primary teeth, Vickers-permanent teeth, SEM). Radiation (6 MV X-ray) was applied to the teeth 5 days (2Gy per day) a week during 6 weeks. This protocol called RTOG 95–01 (60Gy in 6 weeks - 2Gy once a day, 5 x a week) was designed and developed by the Radiation Therapy Oncology Group (RTOG) of the American College of Radiology (ACR) [18 (link)]. Radiation therapy was performed with the SAD technique at a dose rate of 400 MU/min with the anterior and posterior areas. At the end of each week, a wax pattern was removed from radiation intake. After each radiotherapy application, the teeth were taken from the container full of rice, and placed in artificial saliva, and then kept in the oven at 37 °C. This procedure was repeated every day when exposed to radiation.
Radiotherapy was applied to the teeth by a technician under the supervision of a radiation oncologist using the linear accelerator (Clinac iX, Varian, CA, USA) in the Radiation Oncology Department of Inönü University Faculty of Medicine.

For induction chemotherapy, docetaxel (70 mg/m²) and cisplatin (75 mg/m²) were administered as 4-h intravenous infusions on day 1, followed by 5-fluorouracil (1,000 mg/m²) administered as a 24-h continuous infusion for 4 days. The cycles were repeated every 3- weeks, and a total of 3 cycles of induction chemotherapy were administered to the patients. RT was started 3 to 4 weeks after completion of the third cycle of induction chemotherapy. During RT, cisplatin was administered at a dose of 100 mg/m² 3 times every 3 weeks (3-week regimen) or 40 mg/m² weekly (weekly regimen) for 7 weeks depending on the patient's condition or physician's preference. Cisplatin was administered based on creatinine clearance (Clcr). RT was performed using 6 MV photon beams produced by a linear acceleration with 2-dimensional conformal RT (2D-CRT), 3D-CRT via a shrinking field technique using the Clinac IX (Varian Medical Systems, CA), or with IMRT, using the Clinac IX or TomoTherapy (Accuray, Sunnyvale, CA). Patients with gross disease remaining at the neck nodes or primary site were administered 66 to 70 Gy at 2 Gy per fraction 5 days a week. Elective nodal irradiation was administered at a dose of 45 to 50 Gy.

The flux of each beam of the two technology plans was collected by using the Portal Dosimetry function of the Clinac iX linear accelerator of Varian Company of the United States. Gamma analysis, a widely used method for evaluating relative dose contribution [13 ], was carried out using the standard of 3 mm/2%, and the passing rate was verified by statistical dose.

All the patients were laid in the supine position and immobilized by thermoplastic facial masks. After cooling, the masks were cut at the site of the nose for breathing. Isocenters were labeled on the mask using laser markers to ensure reproducibility. Thereafter, the patients underwent contrast-enhanced CT with a thickness of 3 mm per slice.
Six patients with early-stage LC were treated with photon RT (60–66 Gy in 30–36 fractions) to the laryngeal box field. In the CCRT planning of locally advanced LC, gross lesions and lymphadenopathy were treated with 70 Gy, whereas risky lymph node regions were treated with 56–63 Gy. The daily fraction size was 1.8–2 Gy, and RT was delivered 5 days a week. The planning tumor volume (PTV) was 0.3–1 cm extra than the clinical target volume (CTV) to account for organ motion and setup error following international consensus [23 (link)]. The RT planning system (Eclipse version 13.0, Varian, CA, USA) was applied accordingly. All the treatments were administered via the IMRT technique using a linear accelerator (Clinac iX, Varian, CA, USA) with 6 MV or 10 MV.

All dogs were treated with external beam megavoltage RT. Radiation protocol for all dogs consisted of 15 sessions of 3 Gray (Gy), over 5 weeks, on a Monday-Wednesday-Friday schedule to a total dose of 45 Gy. Radiation was delivered with a 6-MV linear accelerator (Clinac iX, Varian, Palo Alto, California) equipped with a 5-mm leaf-width multi-leaf-collimator, using 3D-CRT or IMRT. Additional details on the radiotherapy protocol description are summarized in an additional file (Additional file 3).
All irradiated dogs received approximatively, 0.5 mg/kg/q24, methylprednisolone sodium succinate during the RT protocol until, at least, the first follow-up. Twenty-one dogs were already treated with corticosteroids before the first RT session, 17 dogs had corticosteroid treatment started on first day of protocol. When seizures were reported, anticonvulsant treatment was recorded.