ABSTRACT
PURPOSE: To evaluate 2 published normal tissue complication probability models for radiation-induced hypothyroidism (RHT) on a large cohort of oropharyngeal carcinoma (OPC) patients who were treated with intensity-modulated radiation therapy (IMRT). METHODS AND MATERIALS: OPC patients treated with retrievable IMRT Digital Imaging and Communications in Medicine (DICOMs) data and available baseline and follow-up thyroid function tests were included. Mean dose (Dmean) to the thyroid gland (TG) and its volume were calculated. The study outcome was clinical HT at least 6 months after radiation therapy, which was defined as grade ≥2 HT per Common Terminology Criteria for Adverse Events grading system (symptomatic hypothyroidism that required thyroid replacement therapy). Regression analyses and Wilcoxon rank-sum test were used. Receiver operating characteristic curves and area under the curve for the fitted model were calculated. RESULTS: In the study, 360 OPC patients were included. The median age was 58 years. Most tumors (51%) originated from the base of tongue. IMRT-split field was used in 95%, and median radiation therapy dose was 69.96 Gy. In the study, 233 patients (65%) developed clinical RHT that required thyroid replacement therapy. On multivariate analysis higher Dmean and smaller TG volume maintained the statistically significant association with the risk of clinical RHT (P < .0001). Dmean was significantly higher in patients with clinical RHT versus those without (50 vs 42 Gy, P < .0001). Patients with RHT had smaller TG volume compared with those without (11.8 compared with 12.8 mL, P < .0001). AUC of 0.72 and 0.66 were identified for fitted model versus for the applied Boomsma et al and Cella et al models, respectively. CONCLUSIONS: Volume and Dmean of the TG are important predictors of clinical RHT and shall be integrated into normal tissue complication probability models for RHT. Dmean and thyroid volume should be considered during the IMRT plan optimization in OPC patients.
ABSTRACT
Providing health care to the 1.6 million undocumented immigrants in Texas is an existing challenge. Despite continued growth of this vulnerable population, legislation between 1986 and 2013 has made it more difficult for states to provide adequate and cost-effective care. As this population ages and develops chronic illnesses, Texas physicians, health care administrators, and legislators will be facing a major challenge. New legislation, such as the Affordable Care Act and immigration reform, does not address or attempt to solve the issue of providing health care to this population. One example of inadequate care and poor resource allocation is the experience of undocumented immigrants with end-stage renal disease (ESRD). In Texas, these immigrants depend on safety net hospital systems for dialysis treatments. Often, treatments are provided only when their conditions become an emergency, typically at a higher cost, with worse outcomes. This article reviews the legislation regarding health care for undocumented immigrants, particularly those with chronic illnesses such as ESRD, and details specific challenges facing Texas physicians in the future.
