https://ninho.inca.gov.br/jspui/handle/123456789/14194 Coleção voltada para a inserção de documentos da área de Física Médica 2026-04-20T04:40:47Z https://ninho.inca.gov.br/jspui/handle/123456789/15280 Title: Realização do teste end-to-end para a caracterização de um simulador em radioterapia estereotática de fígado Authors: Burgos, Adam de Freitas; Silva, Leonardo Peres da; Paiva, Eduardo de Abstract: Atualmente, por conta do seu bom prognóstico, uma das alternativas ao tratamento radioterápico do fígado é a radioterapia estereotática corpórea (SBRT), que entrega altas doses ao volume alvo em poucas frações. No entanto, para que se assegure que o elevado valor de dose entregue ao alvo seja o mesmo que o planejado, um teste de verificação de todo o processo (aquisição de imagens, delineamento, planejamento e a entrega da dose) deve ser realizado. Para isto, o objetivo deste trabalho foi desenvolver um simulador, com densidade de água, que leva em conta a posição relativa do fígado e dos órgãos de risco envolvidos neste tratamento, avaliando a influência da movimentação do alvo, em virtude do processo respiratório, no valor da dose por ele recebida. Também foram avaliados os valores de dose nas posições relativas aos órgãos de risco. Description: p. 1-11.: il. color. 2018-01-01T00:00:00Z https://ninho.inca.gov.br/jspui/handle/123456789/15279 Title: Estimating the risk of secondary lung cancer from radiotherapy for pediatric Hodgkin’s lymphoma patients using a mechanistic model Authors: Melgarejo, Hidmer Laulate; Menezes, Artur Ferreira de; Silva, Leonardo Peres da; Magalhães, Denise Maria de Araújo; Soares, Alessandro Facure Neves de Salles; Silva, Ademir Xavier da Abstract: Purpose This study aims to estimate the risk of secondary lung cancer, expressed as the excess absolute risk (EAR), in pediatric patients treated with radiotherapy for Hodgkin’s lymphoma. The project was approved by the INCA Ethics Com mittee under CAAE 55933222.4.0000.5274. Methods The mechanistic and the OED (Organ Equivalent Dose) models were applied for this estimate. Two cases were included in this study, the bell-shaped and the plateau dose–response relationships obtained from the full mechanistic model. OED results were slightly lower using the full mechanistic and plateau models compared with the bell-shaped model. Results For an attained age 45 years after exposure, taking into account the three models, the EAR (cases per 104 person years) values ranged from 19.71 to 25.07 for patients with age at exposure of 15 and 16 years; from 6.98 to 7.22 for patient with age at exposure of 12 years; from 9.73 to 11.29 for patients with age at exposure of 5 and 6 years; and from 16.05 to 16.84 for patient with age at exposure of 13 years. Inadequate coverage and lack of conformity of the treatment target refect high-dose-volume parameters and fnally the estimated risk. Conclusion The mechanistic model makes it possible to estimate the secondary cancer risk and compare it with regard to dose distributions, without having to wait for several years to observe the actual risk Description: p. 857–869.: il. color. 2022-01-01T00:00:00Z https://ninho.inca.gov.br/jspui/handle/123456789/14786 Title: Risk management in radiation therapy with SEVRRA Authors: Joana, Georgia Santos; Gonçalves, Marcello Gomes; Salata, Camila; Teixeira, Flavia Cristina da Silva; Sandrini, Emmily Santos; Bittencourt, Guilherme Rodrigues; Salmon Júnior, Helio Augusto; Fortes, Saulo Santos; Nogueira, Maria do Socorro Abstract: Radiation therapy is a complex treatment modality involving several technological and professional resources as well as a large number of attributions of these professionals with a high degree of interdependence. Thus there are many possibilities of failure in the treatment process that may lead to an accidental exposure. Regulatory agencies have established guidelines in order to prevent accidental exposures through security analysis planning and risk management. The System of EValuation of Risk in RAdiotherapy, also known as SEVRRA, is based on the risk matrix methodology and allows the risk assessment of radiation therapy facilities in a prescriptive way, highlighting events leading to high-risk levels. With SEVRRA it is also possible to establish an analysis of importance of the barriers proposed to avoid or mitigate such events. This work aimed to demonstrate the application of SEVRRA for the risk management of radiation therapy facilities. The risk profile was determined by identifying the highest risk level events, and the barriers of greater impact for the overall risk level. After implementing some missing barriers in the original facility profile, it was achieved a reduction from 31% to 8% in the number of events leading to high-risk level, showing the effectiveness of SEVRRA for the risk management in radiation therapy facilities. Description: p. 1-12.: il. color. 2018-01-01T00:00:00Z https://ninho.inca.gov.br/jspui/handle/123456789/14784 Title: Bony-based and prostate-based image guidance for lo-calized prostate cancer radiotherapy Authors: Fortes, Saulo Santos; Rosa, Luiz Antonio Ribeiro da Abstract: An important modality for the treatment of prostate cancer is teletherapy. The use of image-guided radiotherapy (IGRT) is a valuable tool in this treatment. This study retrospectively compared how repositioning the patient based on bone structure (B-ISO) and the prostate itself (P-ISO) affected the volumetric dose in the rectum, bladder, and clinical target volume (CTV). Additionally, the normal tissue complication probability (NTCP) for the rectum was computed. We evaluated 155 cone-beam computed tomography (CBCT) from 8 patients. The treatment plans used beam modulation techniques. The planning target volume (PTV) margin adopted in both scenarios was 1 cm. The organs of interest were outlined over each CBCT and then treatment plans were applied so that the absorbed dose could be computed. NTCP values were calculated for the rectum. Analyzing dose-volume metrics published by the Quantitative Analysis of Normal Tissue Effects in the Clinic (QUANTEC), there was no significant difference between the two repositioning strategies for the rectum and bladder. There was a slight degradation in CTV coverage for the B-ISO strategy, but still with adequate coverage. Analysis of the uniform equivalent dose (EUD) and NTCP for the rectum showed little sensitivity to the strategy used. The present study showed that the use of CBCT in radiotherapy for prostate cancer treatment did not significantly improve volumetric doses for the rectum, bladder, and CTV, as well as NTCP for the rectum. Description: p. 1-18.: il. color. 2020-01-01T00:00:00Z