Rectal Gas-Induced Dose Changes in Carbon Ion Radiation Therapy for Prostate Cancer: An In Silico Study.

Purpose: This study aims to determine dosimetric influence of rectal gas in carbon ion radiation therapy (CIRT) for prostate cancer and to establish a procedure for removal rectal gas in clinical scenarios.

Materials And Methods: We analyzed 18 prostate cancer cases with bulky rectal gas. The dose distribution was recalculated on computed tomography (CT) with bulky rectal gas (gasCT) after creating the initial plan on a CT without bulky rectal gas, and the doses were transformed using a displacement vector field.

Treatment Planning Comparison of Gantry-based and Fixed Beams for the Treatment of Liver Tumors With Carbon Ion Therapy.

Background/aim: This study aimed to compare the use of a rotating gantry in liver tumor carbon-ion radiotherapy using of a fixed-port for treatment planning.

Materials And Methods: Thirty patients with liver tumors were analyzed. Three treatment plans were developed for each case: one with a rotating gantry with a 360° angle, one with fixed ports of 0° and 90° with a ±20° couch rolling setting, and one with fixed ports of 45° and 90° with a ±20° couch rolling setting.

Evaluation of the availability of single-position treatment with a rotating gantry and the validity of deformable image registration dose assessment for pancreatic cancer carbon-ion radiotherapy.

Background: This study aimed to evaluate the clinical acceptability of rotational gantry-based single-position carbon-ion radiotherapy (CIRT) to reduce the gastrointestinal (GI) dose in pancreatic cancer. We also evaluated the usefulness of the deformable image registration (DIR)-based dosimetry method for CIRT.

Material And Methods: Fifteen patients with pancreatic cancer were analyzed.

A robust treatment planning approach for chest motion in postmastectomy chest wall intensity modulated radiation therapy.

Purpose: Chest wall postmastectomy radiation therapy (PMRT) should consider the effects of chest wall respiratory motion. The purpose of this study is to evaluate the effectiveness of robustness planning intensity modulated radiation therapy (IMRT) for respiratory movement, considering respiratory motion as a setup error.

Material And Methods: This study analyzed 20 patients who underwent PMRT (10 left and 10 right chest walls).

Development of a prediction model for head and neck volume reduction by clinical factors, dose-volume histogram parameters and radiomics in head and neck cancer†.

In external radiotherapy of head and neck (HN) cancers, the reduction of irradiation accuracy due to HN volume reduction often causes a problem. Adaptive radiotherapy (ART) can effectively solve this problem; however, its application to all cases is impractical because of cost and time. Therefore, finding priority cases is essential.

A deep learning-based radiomics approach to predict head and neck tumor regression for adaptive radiotherapy.

Early regression-the regression in tumor volume during the initial phase of radiotherapy (approximately 2 weeks after treatment initiation)-is a common occurrence during radiotherapy. This rapid radiation-induced tumor regression may alter target coordinates, necessitating adaptive radiotherapy (ART). We developed a deep learning-based radiomics (DLR) approach to predict early head and neck tumor regression and thereby facilitate ART.