Introduction: Delivering maximum dose to tumor and minimum dose to normal tissues is the most important goal in radiotherapy. According to ICRU, the maximum acceptable uncertainty in the delivered dose compared to the prescribed dose should be lower than 5%, and this is because of the relationship between absorbed dose, tumor control and normal tissue damage. Absorbed dose accuracy is investiga...

Introduction: During radiotherapy, high accuracy in the dose delivery is required because there is a strong  relationship between the absorbed dose, local tumor control and particularly the normal tissue damage. In  many institutions, in vivo dosimetry using diodes is performed to check the actual dose delivered. In general,  the uncertainty in the dose delivered should fall within  ± 5% of the...

Background: In vivo dosimetry is a method for estimation of overall error in the delivered dose to the patients at the end of radiotherapy process. In this research, two methods for target dose calculation were evaluated on midline and central axis of photon beams in in vivo dosimetry of thorax fields. Materials and Methods: Entrance and exit doses for anterior and lateral fields of thorax were...

background uterine artery embolization (uae) is a minimally invasive procedure performed under fluoroscopy for the treatment of uterine fibroids and accompanied by radiation exposure. objectives to compare ovarian radiation doses during uterine artery embolization (uae) in patients using conventional digital subtraction angiography (dsa) with those using digital flat-panel technology. patients ...

Accuracy in the delivered dose to the patients plays an important and vital role in radiotherapy treatments. This happens because of steep gradient of dose-local control and dose-normal tissue complication probability curves. Dosimetric uncertainty of 3%-4% (one standard deviation) in the delivered dose to the target volume as an acceptable level has been recommended(1-3). In many centers, in v...

PURPOSE To quantify the clinically observed dose enhancement adjacent to cranial titanium fixation plates during post-operative radiotherapy. METHODS Irradiation of a titanium burr hole cover was simulated using Monte Carlo code MCNPX for a 6 MV photon spectrum to investigate backscatter dose enhancement due to increased production of secondary electrons within the titanium plate. The simulat...

Introduction: The Purpose of this study has been measuring midline dose for the patients undergoing brain radiotherapy without any need to build-up cap. Materials and Methods: The study was performed on 28 patients with brain tumor undergoing 15 MV radiotherapy by a Siemens LINAC. To estimate the midline dose, the entrance and exit doses were calculated b...

Introduction Evaluation of the delivered dose of externally wedged photon beams by external diode dosimeters during the treatment process requires the estimation of exit surface dose correction factors in various wedge angles