Differential inflammatory response dynamics in normal lung following stereotactic body radiation therapy with protons versus photons.
Radiother Oncol
; 136: 169-175, 2019 07.
Article
en En
| MEDLINE
| ID: mdl-31015121
ABSTRACT
BACKGROUND AND PURPOSE:
To compare time-dependent changes in lung parenchyma of early-stage non-small cell lung carcinoma (NSCLC) patients after stereotactic body radiation therapy with protons (SBPT) or photons (SBRT). MATERIALS ANDMETHOD:
We retrospectively identified NSCLC patients treated with SBPT and matched each one with a SBRT patient by patient, tumor, and treatment characteristics. Lung parenchyma on serial post-treatment chest computer tomography (CT) scans was deformably registered with the treatment plan to analyze lung density changes as function of dose, quantified by Houndsfield Unit (HU)/Gy. A thoracic radiologist also evaluated the CTs using an established grading system.RESULTS:
We matched 23 SBPT/SBRT pairs, including 5 patients treated with both modalities (internally matched cohort). Normal lung response following SBPT significantly increased in the early time period (CTs acquired <6â¯months, median 3â¯months) post-treatment, and then did not change significantly in the later time period (CTs acquired 6-14â¯months, median 9â¯months). For SBRT, the normal lung response was similar to SBPT in the early time period, but then increased significantly from the early to the late time period (pâ¯=â¯0.007). These differences were most pronounced in sensitive (response >6 HU/Gy) patients and in the internally matched cohort. However, there was no significant difference in the maximum observed response in the entire cohort over all time periods, median 3.4 [IQR, 1.0-5.4] HU/Gy (SBPT) versus 2.5 [1.6-5.2] HU/Gy (SBRT). Qualitative radiological evaluation was highly correlated with the quantitative analysis (pâ¯<â¯0.0001).CONCLUSION:
While there was no significant difference in maximum response after SBPT versus SBRT, dose-defined lung inflammation occurred earlier after proton irradiation. Further investigation is warranted into the mechanisms of inflammation and therapeutic consequences after proton versus photon irradiation.Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Radiocirugia
/
Fotones
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Carcinoma de Pulmón de Células no Pequeñas
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Terapia de Protones
/
Inflamación
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Pulmón
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Neoplasias Pulmonares
Tipo de estudio:
Observational_studies
/
Prognostic_studies
/
Qualitative_research
Límite:
Aged
/
Aged80
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Female
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Humans
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Male
/
Middle aged
Idioma:
En
Revista:
Radiother Oncol
Año:
2019
Tipo del documento:
Article
País de afiliación:
Estados Unidos