title: Evaluation of the radiotherapy treatment planning in the presence of a magnetic valve tissue expander.
abstract: The combination of radiotherapy treatments and breast reconstruction, using temporary tissue expanders, generates several concerns due to the presence of a magnetic valve inside the radiation field. The objective of this work is to evaluate a radiotherapy treatment planning for a patient using a tissue expander. Isodose curve maps, obtained using radiochromic films, were compared to the ones calculated with two different dose calculation algorithms of the Eclipse radiotherapy Treatment Planning System (TPS), considering the presence or absence of the heterogeneity. The TPS calculation considering the presence of the heterogeneity shows changes around 5% in the isodose curves when they were compared with the calculation without heterogeneity correction. This calculation did not take in account the real density value of the heterogeneity. This limitation was quantified to be around 10% in comparison with the TPS calculation and experimental measurements using the radiochromic film. These results show that the magnetic valve should be taken in account in dose calculations of the TPS. With respect to the AAA and Pencil Beam Convolution algorithms, when the calculation is compared with the real distribution, AAA presents a distribution more similar to experimental dose distribution.
authors: Nuclear Engineering Program/Alberto Luiz Coimbra Institute for Graduate Studies and Research in Engineering (COPPE), Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; Laboratório de Física da Radiação Gama-Instituto de Física, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors: Débora M
authors: DM
authors: Trombetta
authors: Laboratório de Física da Radiação Gama-Instituto de Física, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors: Simone C
authors: SC
authors: Cardoso
authors: Nuclear Engineering Program/Alberto Luiz Coimbra Institute for Graduate Studies and Research in Engineering (COPPE), Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; Serviço de Qualidade em Radiações Ionizantes-Instituto Nacional de Câncer, Rio de Janeiro, Brazil.
authors: Victor G L
authors: VG
authors: Alves
authors: Comissão Nacional de Energia Nuclear, Rio de Janeiro, Brazil.
authors: Alessandro
authors: A
authors: Facure
authors: Instituto Nacional de Câncer-Seção de Física Médica, Rio de Janeiro, Brazil.
authors: Delano V S
authors: DV
authors: Batista
authors: Nuclear Engineering Program/Alberto Luiz Coimbra Institute for Graduate Studies and Research in Engineering (COPPE), Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors: Ademir X
authors: AX
authors: da Silva
mesh_terms: D018427:Breast Implants; D005260:Female; D006801:Humans; D016462:Mammaplasty; D009010:Monte Carlo Method; D019047:Phantoms, Imaging; D011880:Radiotherapy Planning, Computer-Assisted; D015625:Tissue Expansion Devices