Radiotherapy result of a case of Kaposi's sarcoma located on the vocal cord.

Kaposi's sarcoma (KS) is an angiogenic tumor. KS lesions frequently develop in the skin and oral cavity mucosa in the head and neck regions, and pure laryngeal localization is extremely rare. We reported a 64-year-old male patient without HIV, HBV, and HCV positivity presented with a hemangiomatous lesion detected incidentally in the right vocal cord. Biopsy was taken for histopathological and immunohistochemical evaluation. Examination revealed that spindle cells were of vascular origin and expressed HHV-8, a specific marker associated with Kaposi's sarcoma-associated herpesvirus. Positron emission tomography-computed tomography (PET/CT) demonstrated an increased fluorodeoxyglucose (FDG) uptake in the vocal cord. The patient was treated with a 30 Gy volumetric arc plan. Disease-free follow-up continues in the first year after low-dose definitive RT. This is the first case report of KS in the vocal cord in which the most detailed data about RT were shared.

Various cost functions evaluation of commercial biologically based treatment planning system for nasopharyngeal cancer.

The aim of this study was to evaluate various combinations of Equivalent Uniform Dose (EUD) based and Dose Volume based (DV) cost functions in terms of target coverage and organ sparing for Nasopharyngeal CA. Ten patients diagnosed with Nasopharyngeal CA were selected for this retrospective study. Different hybrid VMAT plans, including EUD- and DV-based cost functions, were generated for each patient to determine the optimum combination in terms of organ sparing and target coverage. The generated VMAT plans were evaluated based on physical and biological dose parameters. No statistical difference was observed among all plans in terms of target coverage. The p values were ≥ 0.005 for V95, Dmean, and tumor control probability (TCP). The MU efficiency was maximum (67%), and the number of segments (285 segments) was minimum in Hybrid plan. Hybrid plan showed a significant difference compared to others (p = 0.001) in terms of serial organs. Moreover, the combination of serial and parallel complication models provided better reduction of radiation dose in the parotid glands in Plan-3 (p = 0.001). In this study, better protection was obtained when DVH-based cost functions were defined for targets and a combination of EUD- and DVH-based cost functions were used for OARs.

Effect of radiotherapy on coronary arteries and heart in breast-conserving surgery: a dosimetric analysis.

Background There are certain risks of radiotherapy (RT), especially patients with left-sided breast cancer have a higher tendency to develop cardiac complications than the right-sided cancers. This study aims to perform a dosi-metric analysis the effect of RT on coronary arteries and heart in breast-conserving surgery. Patients and methods A total of 40 patients with early stage right and left-sided breast carcinomas (T1/T2 + N0) were randomly selected. RT was delivered to the entire breast, and tumor beds were boosted in these patients using tangential fields with computed tomography based planning. The doses for Left anterior descending coronary artery (LAD), left circumflex coronary artery (LCx), right ventricle (RV), left ventricle (LV), and heart were recorded and median values compared between groups. Results The highest mean of radiation dose in patients with left-sided breast cancer was to LAD 2402.48 ± 838.39 cGy, while the highest mean dose in right-sided breast cancer patients was to RV 130.18 ± 24.92. The highest maximum dose of radiotherapy was applied to heart at left-sided breast cancer patients as well as at right-sides prients. The mean V5 of the LV was 18.68% (6.89-31.69), mean V25 of the LV was 5.22% (0.45-16.54), mean V5 in bilateral ventricles was 23.73% (2.56-26.89), and mean V25 in bilateral ventricles 6.78% (0.63-13.63). Conclusions Especially in left-sided breast cancer, the most direct and best strategy to reduce and protect radiation-induced cardiac injury is to balance dose constraints between several high-dose regions of cardiac substructures and the mean heart dose.