Helical Therapy is Safe for Lung Stereotactic Body Radiation Therapy Despite Limitations in Achieving Sharp Dose Gradients.
Technol Cancer Res Treat
; 16(6): 1173-1178, 2017 12.
Article
em En
| MEDLINE
| ID: mdl-29332448
ABSTRACT
PURPOSE:
We observed that many of our helical therapy lung stereotactic body radiation therapy plans did not meet the Radiation Therapy Oncology Group (RTOG) recommended R50% (volume of 50% of the prescription dose/planning target volume), which characterizes the steepness of dose fall off. We hypothesized that despite not meeting R50%, helical therapy lung stereotactic body radiation therapy plans would confer similar local control and minimal side effects as previously reported using nonhelical treatment platforms. MATERIALS ANDMETHODS:
We report a retrospective review of all consecutive patients treated off-protocol with stereotactic body radiation therapy for peripheral lung lesions from 2008 to 2013 utilizing helical therapy. Seventy-four patients (81 lesions and 79 plans) were treated with doses ranging from 48 to 60 Gy in 3 to 5 fractions prescribed to the edge of the planning target volume.RESULTS:
Forty-eight (61%) plans had major deviation from R50%. Only 1 (<1%) plan had a major deviation from the R100%. All plans had > 95% planning target volume coverage by prescription dose, 7(8.6%) plans with 121% to 133% maximum dose, and lung V20 Gy <10% in 70 (89%) plans. With a median follow-up of 4.7 years (95% confidence interval 4.1-5.3), local control for all patients at 1, 2, and 5 years was 94.6%, 83.4%, and 74%, respectively. For patients with primary stage I-II lung cancer (n = 46), the 1, 2, and 5-year local control 97.2%, 94.2%, and 86.9%; RC 97.6%, 82.5%, and 69.5%; and DM 3%, 16%, and 33.4%, respectively. Patients treated for lung metastases (n = 26) had worse local control at 1, 2, and 5 years 94.4%, 69.3%, and 55.5%, respectively. Side effects were rare with 2 (3%) patients reporting chest wall pain and 6 (8%) patients experiencing radiation pneumonitis, including 1 patient who had grade 5 radiation pneumonitis.CONCLUSIONS:
Helical therapy delivers a safe and effective lung stereotactic body radiation therapy plan, despite not being able to meet RTOG's recommended R50 conformality constraint.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Radiocirurgia
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Pneumonite por Radiação
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Radioterapia de Intensidade Modulada
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Neoplasias Pulmonares
Tipo de estudo:
Etiology_studies
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Guideline
Limite:
Adult
/
Aged
/
Aged80
/
Female
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Humans
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Male
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Middle aged
Idioma:
En
Revista:
Technol Cancer Res Treat
Assunto da revista:
NEOPLASIAS
/
TERAPEUTICA
Ano de publicação:
2017
Tipo de documento:
Article
País de afiliação:
Estados Unidos