BACKGROUND The standard clinical protocol of image-guided IMRT for prostate carcinoma introduces isocenter relocation to restore the conformity of the multi-leaf collimator (MLC) segments to the target as seen in the cone-beam CT on the day of treatment. The large interfractional deformations of the clinical target volume (CTV) still require introduction of safety margins which leads to undesir...

PURPOSE Evaluation of dose degradation by anatomic changes for head-and-neck cancer (HNC) intensity-modulated proton therapy (IMPT) relative to intensity-modulated photon therapy (IMRT) and identification of potential indicators for IMPT treatment plan adaptation. METHODS For 31 advanced HNC datasets, IMPT and IMRT plans were recalculated on a computed tomography scan (CT) taken after about 4...

PURPOSES 1. To determine the optimal pelvic nodal clinical target volume for post-operative treatment of endometrial cancer. 2. To compare the DVH of different treatment planning techniques applied to this new CTV and the surrounding tissues. METHODS AND MATERIALS Based on the literature, we selected a methodology to delineate nodal target volume to define a NEW-CTV and NEW-PTV. Conventional ...

ADAPTIVE RADIATION THERAPY OF PROSTATE CANCER by NING WEN August 2010 Advisor: Dr. Teamour Nurushev Major: Medical Physics Degree: Doctor of Philosophy ART is a close-loop feedback algorithm which evaluates the organ deformation and motion right before the treatment and takes into account dose delivery variation daily to compensate for the difference between planned and delivered dose. It also ...

AIM To assess target volume coverage during prostate image-guided radiotherapy based on bony anatomy alignment and to assess possibility of safety margin reduction. BACKGROUND Implementation of IGRT should influence safety margins. Utilization of cone-beam CT provides current 3D anatomic information directly in irradiation position. Such information enables reconstruction of the actual dose d...

PURPOSE This study investigates (i) the effect of verification protocols on treatment accuracy and PTV margins for partial breast and boost breast radiotherapy with short fractionation schema (15 fractions), (ii) the effect of deformation of the excision cavity (EC) on PTV margin size, (iii) the imaging dose required to achieve specific PTV margins. METHODS AND MATERIALS Verification images u...

BACKGROUND We prospectively assessed the utility of intensity-modulated radiation therapy (IMRT) with urethral dose reduction and a small margin between the clinical target volume (CTV) and the planning target volume (PTV) for patients with localized prostate cancer. METHODS The study population was 110 patients in low- (14.5%), intermediate- (41.8%), and high-risk (43.6%) categories. Three g...

INTRODUCTION As part of French residents' radiotherapy training, delineation workstations were available at a national teaching course. We report a prospective comparative study of a non small cell lung cancer (NSCLC) case delineated by 120 residents before and after a radioanatomy/radiotherapy lecture. MATERIALS AND METHODS The case of a patient with right upper lobe non small cell lung canc...

PurposeTo investigate the potential of an offline Adaptive Radiotherapy (ART) strategy, based on interfractional vagina motion (IVM) measured using fiducial markers (FM) during initial number fractions, CTV to PTV margins in post-operative gynecological patients.Materials and methodsIn 18 patients, treated post-operatively for tumors, systematic residual IVM was quantified after simulating ART ...