ABSTRACTBackground: Although Electronic Portal imaging Devices (EPIDs) have originally developed for positioning verification, they can also be used for dosimetric purposes. In the current work, the dose response of minimum detectable thickness of a Scanning Liquid filled Ion Chamber EPID, SLIC-EPID, and the variation of transmitted dose with the shift of inhomogeneity inside of phantom was al...

An independent in vivo dose verification procedure for IMRT treatments of head and neck cancers was developed. Results of 177 intracavitary TLD measurements from 10 patients are presented. The study includes data from 10 patients with cancer of the rhinopharynx or the thyroid treated with dynamic IMRT. Dose verification was performed by insertion of a flexible naso-oesophageal tube containing T...

BACKGROUND In volumetric modulated arc therapy (VMAT), gantry angles, dose rate and the MLC positions vary with the radiation delivery. The quality assurance (QA) system should be able to catch the planning and machine errors. The aim of this study was to investigate the sensitivity of three VMAT QA systems to machine errors. METHODS Several types of potential linac machine errors unique to V...

Introduction: Electronic portal imaging devices (EPIDs) are fundamentally used for instantaneous verification of the patient set‐up, block shape, and leaf positions during radiation therapy. In radiotherapy, situations arise in which an inclined PTV must be treated mutually with adjacent nodal regions. This methodology is most widely used for matching tangential/lateral breas...

Amaç: Bu çalışmanın amacı, Yoğunluk Ayarlı Radyoterapi (YART) planlarının hastaya özel kalite kontrolü için kullanılan film, in-vivo elektronik portal görüntüleme cihazları (Electronically Portal Imaging Devices-EPID) ve iki boyutlu (2B) detektörlerin hata tespit yeteneklerini karşılaştırmaktır. Yöntem: çalışmada, Alderson Rando fantom kullanılmıştır. İlk olarak, fantomun bilgisayarlı tomografi...

PURPOSE To investigate the use of a commercially available video-based EPID for in vivo dosimetry during treatment of prostate cancer patients. METHODS For 10 prostate cancer patients, the inter-fraction variation within measured portal dose images (PDIs) was assessed and measured PDIs were compared with corresponding predicted PDIs based on the planning CT scan of the patient. RESULTS For ...

The ultimate check of the actual dose delivered to a patient in radiotherapy can only be achieved by using in vivo dosimetry. This work reports a pilot study to test the applicability of a thermoluminescent dosimetric system for performing in vivo entrance dose measurements in external photon beam radiotherapy. The measurements demonstrated the value of thermoluminescent dosimetry as a treatmen...

Introduction: Radiation therapy is one of the methods of cancer treatment. In this method, it is necessary to avoid harming the healthy tissues of the patient which is in the vicinity of the target, as much as possible. Treatment verification is one of the most important steps of radiation therapy which has two usual methods, using Port film and EPID. The accuracy and precision of treatment in ...