D Granero1, C Candela-Juan2, J Vijande3, F Ballester4, J Perez-Calatayud5, D Jacob6, F Mourtada6. 1. Department of Radiation Physics, ERESA, Hospital General Universitario, Valencia 46014, Spain. 2. National Dosimetry Centre (CND), Instituto Nacional de Gestión Sanitaria, Valencia 46009, Spain. 3. Department of Atomic, Molecular and Nuclear Physics, University of Valencia, Burjassot 46100, Spain and Instituto de Física Corpuscular (UV-CSIC), Burjassot 46100, Spain. 4. Department of Atomic, Molecular and Nuclear Physics, University of Valencia, Burjassot 46100, Spain and Instituto de Fisica Corpuscular (UV-CSIC), Burjassot 46100, Spain. 5. Radiation Oncology Department, La Fe University and Polytechnic Hospital, Valencia 46026, Spain and Department of Radiotherapy, Clínica Benidorm, Benidorm 03501, Spain. 6. Department of Radiation Oncology, Helen F. Graham Cancer Center, Christiana Care Health System, Newark, Delaware 19713.
Abstract
PURPOSE: High dose rate (HDR) brachytherapy for treatment of small skin lesions using the Leipzig and Valencia applicators is a widely used technique. These applicators are equipped with an attachable plastic cap to be placed during fraction delivery to ensure electronic equilibrium and to prevent secondary electrons from reaching the skin surface. The purpose of this study is to report on the dosimetric impact of the cap being absent during HDR fraction delivery, which has not been explored previously in the literature. METHODS: geant4 Monte Carlo simulations (version 10.0) have been performed for the Leipzig and Valencia applicators with and without the plastic cap. In order to validate the Monte Carlo simulations, experimental measurements using radiochromic films have been done. RESULTS: Dose absorbed within 1 mm of the skin surface increases by a factor of 1500% for the Leipzig applicators and of 180% for the Valencia applicators. Deeper than 1 mm, the overdosage flattens up to a 10% increase. CONCLUSIONS: Differences of treating with or without the plastic cap are significant. Users must check always that the plastic cap is in place before any treatment in order to avoid overdosage of the skin. Prior to skin HDR fraction delivery, the timeout checklist should include verification of the cap placement.
PURPOSE: High dose rate (HDR) brachytherapy for treatment of small skin lesions using the Leipzig and Valencia applicators is a widely used technique. These applicators are equipped with an attachable plastic cap to be placed during fraction delivery to ensure electronic equilibrium and to prevent secondary electrons from reaching the skin surface. The purpose of this study is to report on the dosimetric impact of the cap being absent during HDR fraction delivery, which has not been explored previously in the literature. METHODS: geant4 Monte Carlo simulations (version 10.0) have been performed for the Leipzig and Valencia applicators with and without the plastic cap. In order to validate the Monte Carlo simulations, experimental measurements using radiochromic films have been done. RESULTS: Dose absorbed within 1 mm of the skin surface increases by a factor of 1500% for the Leipzig applicators and of 180% for the Valencia applicators. Deeper than 1 mm, the overdosage flattens up to a 10% increase. CONCLUSIONS: Differences of treating with or without the plastic cap are significant. Users must check always that the plastic cap is in place before any treatment in order to avoid overdosage of the skin. Prior to skin HDR fraction delivery, the timeout checklist should include verification of the cap placement.
Authors: S Rodríguez; M Arenas; C Gutierrez; J Richart; J Perez-Calatayud; F Celada; M Santos; A Rovirosa Journal: Clin Transl Oncol Date: 2017-08-14 Impact factor: 3.405
Authors: Silvia Rodríguez Villalba; Maria Jose Perez-Calatayud; Juan Antonio Bautista; Vicente Carmona; Francisco Celada; Alejandro Tormo; Teresa García-Martinez; José Richart; Manuel Santos Ortega; Magda Silla; Facundo Ballester; Jose Perez-Calatayud Journal: J Contemp Brachytherapy Date: 2016-08-09