Three-Dimensional Gel Dosimetry in a Simulated Postmastectomy with Expandable Prosthesis Radiotherapy

Autor(es)

Pavoni, Juliana Fernandes ; Lizar, Jessica Caroline ; Borges, Leandro Frederiche ; Nicolucci, Patricia ; Krutman, Yanai ; Baffa, Oswaldo

• Tipo de documento: Artigo Científico
• Fonte: GELS; v. 11, n. 5, p. 13-pg., 2025-04-30.

Resumo

Postmastectomy radiation therapy (PMRT) is an adjuvant treatment for breast cancer. Some mastectomized women undergoing PMRT can have breast reconstruction with expander implant reconstruction. However, the expander implant contains a magnetic metal port for its inflation, and in patients with a high risk of recurrence, the PMRT is performed before the expander replacement. The difficulties in radiation treatment near high-Z metals are mainly due to dose alterations around them. Therefore, this study proposes using a realistic breast phantom and gel dosimetry to investigate the effects of the metallic parts of the expandable prosthesis on the 3D delivery of the treatment. A conformal radiation treatment was planned and delivered to the gel phantom with the metal port. MAGIC-f gel was used with magnetic resonance imaging for dose assessment. The treatment plan dose distribution was compared to the measured dose distribution by gamma analysis (3%/3 mm/15% threshold). A significant gamma fail region was found near the metal port, corresponding to a dose reduction of approximately 5%. This underdose is within the tolerance threshold for dose heterogeneity established by the International Commission on Radiation Units (ICRU), but should be considered when treating these patients. (AU)

• Processo FAPESP: 13/07699-0 - Centro de Pesquisa, Inovação e Difusão em Neuromatemática - NeuroMat
• Beneficiário: Oswaldo Baffa Filho
• Modalidade de apoio: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs
• Processo FAPESP: 18/05982-0 - P&D&I em metrologia das radiações na área da saúde
• Beneficiário: Linda Viola Ehlin Caldas
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 21/02254-6 - Aplicações de ferramentas de aprendizado de máquina em radioterapia
• Beneficiário: Juliana Fernandes Pavoni
• Modalidade de apoio: Auxílio à Pesquisa - Regular