Development and Evaluation of Jaw Position Detection Method in Jaw-tracking Delivery Using an Electronic Portal Imaging Device Cine Mode.

Objectives: To develop a method for detecting jaw positions during jaw-tracking delivery to ensure an accurate delivery of radiation to patients using an electronic portal imaging device (EPID) in the cine mode on a linear accelerator for radiotherapy.

Materials: A bidirectional picket fence (BPF) plan was used in a novel application to detect jaw positions during jaw-tracking delivery. In the BPF plan, jaws tracked multileaf collimator (MLC) apertures.

Semiautomatic Treatment Planning for the Field-in-field Technique in Whole Brain Irradiation.

Objectives: In radiation therapy, the field-in-field (FIF) technique is used to prevent the administration of unnecessarily high doses to reduce toxicity. Recently, the FIF technique has been used for whole brain irradiation (WBI). Using the FIF technique, the volume that receives a higher than prescribed dose (hotspot) can be largely reduced; however, the treatment planning requires time.

Patient organ doses from megavoltage computed tomography delivery with a helical tomotherapy unit using a general treatment planning system.

The purpose of this study was to quantify actual patient organ doses from megavoltage computed tomography (MVCT) using an MVCT beam model of a helical tomotherapy unit in a general treatment planning system (TPS). Dosimetric parameters (percentage depth dose, lateral beam profile, and longitudinal beam profile) of the MVCT beam were measured using Gafchromic EBT3 films (ISP Corporation, Wayne, NJ, USA) and used for beam modeling in a Pinnacle3 TPS (Philips, Amsterdam, Netherlands); this TPS is widely used with linear accelerators. The created beam model was adjusted and validated by assessing point doses in a cylindrical phantom in static and helical beam plans with fine, normal and coarse pitches.

[Severe Graves' ophthalmopathy accompanied by myasthenia gravis].

We report a 53-year-old woman with severe Graves' ophthalmopathy accompanied by uncontrolled myasthenia gravis. She presented remarkable exophthalmos, chemosis, and restriction of eye movement. Despite plasma exchange, steroid pulse therapy, local injection of steroid, and irradiation, ocular symptoms did not ameliorate.