The Learning Curve and Inter-Observer Variability in Contouring the Hippocampus under the Hippocampal Sparing Guidelines of Radiation Therapy Oncology Group 0933.

Hippocampal-sparing brain radiotherapy (HS-BRT) in cancer patients results in preservation of neurocognitive function after brain RT which can contribute to patients' quality of life (QoL). The crucial element in HS-BRT treatment planning is appropriate contouring of the hippocampus. Ten doctors delineated the left and right hippocampus (LH and RH, respectively) on 10 patients' virtual axial images of brain CT fused with T1-enhanced MRI (1 mm) according to the RTOG 0933 atlas recommendations. Variations in the spatial localization of the structure were described in three directions: right-left (X), cranio-caudal (Y), and forward-backward (Z). Discrepancies concerned three-dimensional localization, shape, volume and size of the hippocampus. The largest differences were observed in the first three delineated cases which were characterized by larger hippocampal volumes than the remaining seven cases. The volumes of LH of more than half of hippocampus contours were marginally bigger than those of RH. Most differences in delineation of the hippocampus were observed in the area of the posterior horn of the lateral ventricle. Conversely, a large number of hippocampal contours overlapped near the brainstem and the anterior horn of the lateral ventricle. The most problematic area of hippocampal contouring is the posterior horn of the lateral ventricle. Training in the manual contouring of the hippocampus during HS-BRT treatment planning under the supervision of experienced radiation oncologists is necessary to achieve optimal outcomes. This would result in superior outcomes of HS-BRT treatment and improvement in QoL of patients compared to without HS-BRT procedure. Correct delineation of the hippocampus is problematic. This study demonstrates difficulties in HS-BRT treatment planning and highlights critical points during hippocampus delineation.

Simultaneous occurrence of non-Hodgkin lymphoma, renal cell carcinoma and oncocytoma: A case report.

We herein report the case of a 74 year-old woman with a diffuse large B-cell lymphoma and bilateral renal masses identified on computed tomography scans during the initial staging process. Following partial bilateral nephrectomy, histopathological examination revealed renal cell carcinoma (RCC) and oncocytoma in the left and the right kidneys, respectively. Shortly afterwards, lymphoma of the left palatine tonsil was diagnosed and the patient received chemotherapy with rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP regimen), followed by radiotherapy. Due to metastasis of the RCC to the right breast, pancreas and the area of the left psoas major muscle, systemic treatment with pazopanib was commenced. To the best of our knowledge, this is the first reported case of simultaneous diagnosis of non-Hodgkin lymphoma (NHL), RCC and oncocytoma. The aim of this study was to review the related literature, discuss issues regarding the management of this unusual case and identify possible common etiopathological mechanisms underlying the simultaneous occurrence of NHL, RCC and oncocytoma.