Tarcisio Passos Ribeiro de Campos1, Bruno M Mendes1,2, Bruno Trindade1, Wagner L Araujo1. 1. Programa de Ciências e Técnicas Nucleares, Departamento de Engenharia Nuclear, Universidade Federal de Minas Gerais, Av. Presidente Antônio Carlos, 6627, EE, Bloco 4, S.2285, CEP: 31270901, Belo Horizonte, MG, Brazil. 2. Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN), Av. Presidente Antônio Carlos, 6.627, CEP 31270-901, Belo Horizonte, MG, Brazil.
Abstract
AIM: The present study evaluated the increment of cardiac risk (CR) and absorbed dose in radiotherapy of the internal mammary chain (IMC), in particular with photon portals of 4 6 MV, and cobalt therapy (Co60); and, electron portals of 8, 12 and 16 MeV applied in the left breast, considering the adoption of a combined photon (16 Gy) and electron (30 Gy) protocols. MATERIALS AND METHODS: The modified ICRP-reference female model of 60 kg, 163 cm and 43 years of age, coil RCP-AF, was modelled. The MCNP6/SICODES codes were employed, where the spatial dose distributions and dose-volume histograms were generated. Toxicity limits and a CR model were considered. RESULTS: CR associated with the 6 MV, 4 MV and Co60 portals increased 41.1; 40.6 and 34.5%, respectively; while, in 8, 12 and 16 MeV portals, they were 5.0, 32.5 and 49.2%, respectively. High anomalous scatter radiation from electron portals was found in the left lung providing an average dose of 3.3-5.0 Gy. CONCLUSIONS: To RCP-AF, the Co60 portal for IMC-RT presented more attractive dose distribution, whose 16 Gy for photon-component produced less CR increase, 5% lower than the other photon portals. Considering electron portals, the smallest CR increase was produced by 8 MeV portal while 12-16 MeV made the risk higher. There is a call for a less hardened energetic spectrum in order to reduce CR; however, holding suitable IMC penetration. A combined Co60/8-12 MeV may bring benefits, reducing CR. The lowest risk was found to 46 Gy electron portals exclusively.
AIM: The present study evaluated the increment of cardiac risk (CR) and absorbed dose in radiotherapy of the internal mammary chain (IMC), in particular with photon portals of 4 6 MV, and cobalt therapy (Co60); and, electron portals of 8, 12 and 16 MeV applied in the left breast, considering the adoption of a combined photon (16 Gy) and electron (30 Gy) protocols. MATERIALS AND METHODS: The modified ICRP-reference female model of 60 kg, 163 cm and 43 years of age, coil RCP-AF, was modelled. The MCNP6/SICODES codes were employed, where the spatial dose distributions and dose-volume histograms were generated. Toxicity limits and a CR model were considered. RESULTS: CR associated with the 6 MV, 4 MV and Co60 portals increased 41.1; 40.6 and 34.5%, respectively; while, in 8, 12 and 16 MeV portals, they were 5.0, 32.5 and 49.2%, respectively. High anomalous scatter radiation from electron portals was found in the left lung providing an average dose of 3.3-5.0 Gy. CONCLUSIONS: To RCP-AF, the Co60 portal for IMC-RT presented more attractive dose distribution, whose 16 Gy for photon-component produced less CR increase, 5% lower than the other photon portals. Considering electron portals, the smallest CR increase was produced by 8 MeV portal while 12-16 MeV made the risk higher. There is a call for a less hardened energetic spectrum in order to reduce CR; however, holding suitable IMC penetration. A combined Co60/8-12 MeV may bring benefits, reducing CR. The lowest risk was found to 46 Gy electron portals exclusively.
Authors: Lawrence B Marks; Ellen D Yorke; Andrew Jackson; Randall K Ten Haken; Louis S Constine; Avraham Eisbruch; Søren M Bentzen; Jiho Nam; Joseph O Deasy Journal: Int J Radiat Oncol Biol Phys Date: 2010-03-01 Impact factor: 7.038
Authors: R Arriagada; M G Lê; H Mouriesse; F Fontaine; J Dewar; F Rochard; M Spielmann; J Lacour; M Tubiana; D Sarrazin Journal: Radiother Oncol Date: 1988-03 Impact factor: 6.280
Authors: Philip M Poortmans; Sandra Collette; Carine Kirkove; Erik Van Limbergen; Volker Budach; Henk Struikmans; Laurence Collette; Alain Fourquet; Philippe Maingon; Mariacarla Valli; Karin De Winter; Simone Marnitz; Isabelle Barillot; Luciano Scandolaro; Ernest Vonk; Carla Rodenhuis; Hugo Marsiglia; Nicola Weidner; Geertjan van Tienhoven; Christoph Glanzmann; Abraham Kuten; Rodrigo Arriagada; Harry Bartelink; Walter Van den Bogaert Journal: N Engl J Med Date: 2015-07-23 Impact factor: 91.245
Authors: Michelle S Ludwig; Marsha D McNeese; Thomas A Buchholz; George H Perkins; Eric A Strom Journal: Int J Radiat Oncol Biol Phys Date: 2010-01-01 Impact factor: 7.038
Authors: U Veronesi; N Cascinelli; R Bufalino; A Morabito; M Greco; D Galluzzo; V Delle Donne; R De Lellis; P Piotti; V Sacchini Journal: Ann Surg Date: 1983-12 Impact factor: 12.969
Authors: Steven J Frank; Marsha D McNeese; Eric A Strom; George Perkins; Mohammad Salehpour; Naomi Schechter; Thomas A Buchholz Journal: Clin Breast Cancer Date: 2004-02 Impact factor: 3.225