Radiobiological evaluation of intensity modulated radiation therapy treatments of patients with head and neck cancer: A dual-institutional study.
In clinical practice, evaluation of clinical efficacy of treatment planning stems from the radiation oncologist's experience in accurately targeting tumors, while keeping minimal toxicity to various organs at risk (OAR) involved. A more objective, quantitative method may be raised by using radiobiological models. The purpose of this work is to evaluate the potential correlation of OAR-related toxicities to its radiobiologically estimated parameters in simultaneously integrated boost (SIB) intensity modulated radiation therapy (IMRT) plans of patients with head and neck tumors at two institutions. Lyman model for normal tissue complication probability (NTCP) and the Poisson model for tumor control probability (TCP) models were used in the Histogram Analysis in Radiation Therapy (HART) analysis. In this study, 33 patients with oropharyngeal primaries in the head and neck region were used to establish the correlation between NTCP values of (a) bilateral parotids with clinically observed rates of xerostomia, (b) esophagus with dysphagia, and (c) larynx with dysphagia. The results of the study indicated a strong correlation between the severity of xerostomia and dysphagia with Lyman NTCP of bilateral parotids and esophagus, respectively, but not with the larynx. In patients without complications, NTCP values of these organs were negligible. Using appropriate radiobiological models, the presence of a moderate to strong correlation between the severities of complications with NTCP of selected OARs suggested that the clinical outcome could be estimated prior to treatment.
Department of Radiation Oncology, University of Texas Health Science Center, San Antonio, TX, USA.
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Narayanasamy
Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD, USA.
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Pyakuryal
Department of Radiation Oncology, BP Koirala Memorial Cancer Hospital, Bharatpur, Nepal.
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S
Pandit
Department of Radiation Oncology, University of Texas Health Science Center, San Antonio, TX, USA.
J
J
Vincent
Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD, USA.
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C
Lee
Department of Radiation Oncology, University of Texas Health Science Center, San Antonio, TX, USA.
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P
Mavroidis
Department of Radiation Oncology, University of Texas Health Science Center, San Antonio, TX, USA.
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N
Papanikolaou
Department of Radiation Medicine, University of Kentucky, Lexington, KY, USA.
M
M
Kudrimoti
Department of Radiation Oncology, Mayo Clinic, Rochester, MN, USA.
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Sio
Dysphagia; head and neck cancers; normal tissue complication probability; radiobiology; xerostomia