Secondary malignancy risk for patients with localized prostate cancer after intensity-modulated radiotherapy with and without flattening filter.
J Appl Clin Med Phys
; 21(12): 197-205, 2020 Dec.
Article
em En
| MEDLINE
| ID: mdl-33147377
ABSTRACT
Men treated for localized prostate cancer by radiotherapy have often a remaining life span of 10 yr or more. Therefore, the risk for secondary malignancies should be taken into account. Plans for ten patients were evaluated which had been performed on an Oncentra® treatment planning system for a treatment with an Elekta Synergy™ linac with Agility™ head. The investigated techniques involved IMRT and VMTA with and without flattening filter. Different dose response models were applied for secondary carcinoma and sarcoma risk in the treated region and also in the periphery. As organs at risk we regarded for carcinoma risk urinary bladder, rectum, colon, esophagus, thyroid, and for sarcoma risk bone and soft tissue. The excess absolute risk (EAR) was found very similar in the treated region for both techniques (IMRT and VMAT) and also for both with and without flattening filter. The secondary sarcoma risk resulted about one magnitude smaller than the secondary carcinoma risk. The EAR to the peripheral organs was statistically significant reduced by application of the flattening filter free mode concerning the flattening filter as main source of scattered dose. Application of flattening filter free mode can thus support to reduce second malignancy risk for patients with localized prostate cancer.
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Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Neoplasias da Próstata
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Segunda Neoplasia Primária
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Radioterapia de Intensidade Modulada
Tipo de estudo:
Etiology_studies
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Risk_factors_studies
Limite:
Humans
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Male
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article