Dosimetric Analysis of Radiation-Induced Gastric Bleeding
Autor: | Daniel P. Normolle, Charlie C. Pan, Laura A. Dawson, William D. Ensminger, Randall K. Ten Haken, Mary Feng, Theodore S. Lawrence, Sudha Amarnath |
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Jazyk: | angličtina |
Rok vydání: | 2012 |
Předmět: |
Liver Cirrhosis
Male Cancer Research medicine.medical_specialty Cirrhosis Gastric bleeding Carcinoma Hepatocellular Time Factors medicine.medical_treatment Stomach Diseases Radiation induced Gastroenterology Article Cholangiocarcinoma Internal medicine medicine Humans Radiology Nuclear Medicine and imaging Retrospective Studies Likelihood Functions Radiation Models Statistical business.industry Stomach Liver Neoplasms Dose fractionation Retrospective cohort study medicine.disease Radiation therapy medicine.anatomical_structure Oncology Female Dose Fractionation Radiation Radiotherapy Conformal Complication business Nuclear medicine Colorectal Neoplasms Gastrointestinal Hemorrhage |
Popis: | Purpose Radiation-induced gastric bleeding has been poorly understood. In this study, we described dosimetric predictors for gastric bleeding after fractionated radiation therapy. Methods and Materials The records of 139 sequential patients treated with 3-dimensional conformal radiation therapy (3D-CRT) for intrahepatic malignancies were reviewed. Median follow-up was 7.4 months. The parameters of a Lyman normal tissue complication probability (NTCP) model for the occurrence of ≥grade 3 gastric bleed, adjusted for cirrhosis, were fitted to the data. The principle of maximum likelihood was used to estimate parameters for NTCP models. Results Sixteen of 116 evaluable patients (14%) developed gastric bleeds at a median time of 4.0 months (mean, 6.5 months; range, 2.1-28.3 months) following completion of RT. The median and mean maximum doses to the stomach were 61 and 63 Gy (range, 46-86 Gy), respectively, after biocorrection of each part of the 3D dose distributions to equivalent 2-Gy daily fractions. The Lyman NTCP model with parameters adjusted for cirrhosis predicted gastric bleed. Best-fit Lyman NTCP model parameters were n =0.10 and m =0.21 and with TD 50 (normal) = 56 Gy and TD 50 (cirrhosis) = 22 Gy. The low n value is consistent with the importance of maximum dose; a lower TD 50 value for the cirrhosis patients points out their greater sensitivity. Conclusions This study demonstrates that the Lyman NTCP model has utility for predicting gastric bleeding and that the presence of cirrhosis greatly increases this risk. These findings should facilitate the design of future clinical trials involving high-dose upper abdominal radiation. |
Databáze: | OpenAIRE |
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