Comparison of rectal dose reduction by a hydrogel spacer among 3D conformal radiotherapy, volumetric-modulated arc therapy, helical tomotherapy, CyberKnife and proton therapy.
J Radiat Res
; 61(3): 487-493, 2020 May 22.
Article
em En
| MEDLINE
| ID: mdl-32211861
ABSTRACT
This study aimed to evaluate the rectal dose reduction with hydrogel spacer in 3D conformal radiotherapy (3DCRT), volumetric modulated arc therapy (VMAT), helical tomotherapy (HT), CyberKnife (CK) and proton therapy. Twenty patients who had hydrogel spacer for prostate radiotherapy were retrospectively enrolled. Computed tomography (CT) images with or without hydrogel spacer were used to evaluate rectal dose reduction. In total, 200 plans (20 patients × 2 CT images × 5 techniques) were created using the following criteria 3DCRT, VMAT and HT [76 Gy/38 fractions (Fr), planning target volume (PTV) D50%], CK (36.25 Gy/5 Fr, PTV D95%) and proton therapy (63 GyE/21 Fr, PTV D50%). Rectal dose reduction was evaluated using low-/middle-dose (D20%, D50% and D80%) and high-dose (D2%) ranges. Rectal dose reduction of each dose index was compared for each technique. Significant rectal dose reduction (P < 0.001) between the treatment plans on pre- and post-CT images were achieved for all modalities for D50%, D20% and D2%. In particular, the dose reduction of high-dose (D2%) ranges were -40.61 ± 11.19, -32.44 ± 5.51, -25.90 ± 9.89, -13.63 ± 8.27 and -8.06 ± 4.19%, for proton therapy, CK, HT, VMAT and 3DCRT, respectively. The area under the rectum dose-volume histogram curves were 34.15 ± 3.67 and 34.36 ± 5.24% (P = 0.7841) for 3DCRT with hydrogel spacer and VMAT without hydrogel spacer, respectively. Our results indicated that 3DCRT with hydrogel spacer would reduce the medical cost by replacing the conventional VMAT without spacer for prostate cancer treatment, from the point of view of the rectal dose. For the high-dose gradient region, proton therapy and SBRT with CK showed larger rectal dose reduction than other techniques.
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Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Neoplasias da Próstata
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Radiocirurgia
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Hidrogéis
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Radioterapia Conformacional
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Radioterapia de Intensidade Modulada
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Terapia com Prótons
Tipo de estudo:
Observational_studies
Limite:
Humans
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Male
Idioma:
En
Revista:
J Radiat Res
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Japão