Impact of Radiation Therapy Dose Escalation on Prostate Cancer Outcomes and Toxicities.
Am J Clin Oncol
; 41(4): 409-415, 2018 04.
Article
em En
| MEDLINE
| ID: mdl-27014930
ABSTRACT
OBJECTIVES:
Freedom from biochemical failure (FFBF) is a common primary outcome of randomized-controlled trials of prostate cancer (PCa). We aimed to determine how increasing the PCa biologically equivalent dose (BED) of external radiation therapy (RT) is correlated with FFBF and overall patientoutcomes:
overall survival (OS), distant metastasis (DM), and cancer-specific mortality (CSM); as well as genitourinary (GU), and gastrointestinal toxicities. MATERIALS ANDMETHODS:
We performed a meta-analysis of 6884 PCa patients from 12 randomized-controlled trials of external beam RT. Mixed effects regression models were used to estimate weighted linear relationships between BED and observed percentages of 5- and 10-year outcomes. For toxicities, a subset analysis of using 3-dimensional conformal RT (3D-CRT) versus intensity-modulated RT (IMRT) was performed.RESULTS:
Increasing BED correlated with improved FFBF 10-year absolute improvement of 9.6% and 7.2% for low-risk and intermediate-risk patients, respectively (P<0.05); but not with improvement of OS, DM, or CSM at either time point. BED escalation was not correlated with increased acute toxicities; it was correlated with increased late gastrointestinal toxicities in patients treated with 3D-CRT (1.5% increase over BED range, P<0.01). IMRT patients had significantly fewer late toxicities, despite being treated at higher BED.CONCLUSIONS:
RT BED escalation has resulted in significantly improved PCa FFBF at up to 10 years; but not with improvement in OS, DM, or CSM. Thus, FFBF is a poor surrogate of overall patient outcomes for trials of RT. Late toxicities were less frequent with IMRT than with 3D-CRT, even at higher BED.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Neoplasias da Próstata
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Lesões por Radiação
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Radioterapia Conformacional
/
Radioterapia de Intensidade Modulada
Tipo de estudo:
Clinical_trials
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Etiology_studies
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Observational_studies
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Prognostic_studies
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Risk_factors_studies
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Systematic_reviews
Limite:
Humans
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Male
Idioma:
En
Ano de publicação:
2018
Tipo de documento:
Article