Performance of an offline systematic error correction strategy in pediatric patients receiving adjuvant conformal radiotherapy for Wilm's tumor.

BACKGROUND: Radiotherapy plays a key role as an adjuvant treatment in pediatric Wilm's tumor, improving both survival and quality of life. The success of radiotherapy depends on the precise delivery of radiation dose to the tumor while sparing radiosensitive structures in the vicinity of the tumor. Pediatric patients pose unique challenges in achieving accurate radiotherapy delivery due to their inability to understand instructions and the high radiosensitivity of their tissues. Thus, it is important to determine the optimum geometric verification strategy that will ensure accurate delivery of the prescribed target as specified in the patient's treatment plan. PURPOSE: To evaluate the performance of an offline geometric correction strategy in ensuring accuracy and reproducibility during radiotherapy delivery in Wilm's tumor patients. MATERIAL AND METHODS: The extended no-action level offline correction strategy was applied in the radiotherapy delivery of 45 Wilm's tumor patients. Gross errors from the first three fractions were used to calculate the mean errors which were then applied as offline correction factors. Mean errors among different groups were compared using a two-way analysis of variance (ANOVA) and Dunnett's pairwise comparisons. All statistical analyses and data visualization were performed using GraphPad Prism version 7 (Insight Partners, GraphPad Holdings, LLC). RESULTS: A total of 45 patients were included in the study. In all three orthogonal directions, the recorded gross errors were significantly lower after the application of the systematic error corrections. Random errors were significantly larger in the longitudinal direction compared to lateral (mean difference = 0.28, p = 0.036) and vertical directions (mean difference = 0.37 cm, p = 0.003). Patients' age was a significant predictor of random errors whereby the magnitude of random error decreased with increasing age. CONCLUSION: This study shows that the offline correction strategy used is effective in ensuring the accuracy of radiotherapy delivery in pediatric Wilm's tumor patients.

Mycosis fungoides with spongiosis: a case report.

BACKGROUND: Mycosis fungoides (MF) is the most common form of cutaneous T-cell lymphoma (CTCL). CTCL are an uncommon, heterogeneous group of non-Hodgkin lymphomas (NHLs) of T- and B-cell origin where the skin is the primary organ of involvement. It is characterized by malignant CD4+ T-cells infiltrating the skin and other organs, leading to progressive skin and systemic involvement. Histopathologically, MF is characterized by atypical lymphocytes demonstrating epidermotropism without spongiosis. Spongiosis is the histological hallmark of intercellular epidermal edema, viewed as clear spaces within the epidermis, and is very common in benign inflammatory dermatoses. Very few studies have reported MF in sub-Saharan Africa (SSA). We are reporting a case of MF with a rare presentation of spongiosis treated successfully with a low dose total skin electron beam therapy (TSEBT) followed by maintenance therapy of low dose Methotrexate (MT) at the Ocean Road Cancer Institute (ORCI) in Tanzania. This is the first case of MF to be managed with low-dose TSEBT in Tanzania. The authors wish to create awareness of the disease among physicians and pathologists and expand on the data paucity in SSA. CASE DESCRIPTION: We are reporting a case of a 31-year-old male of African origin who self-referred to our oncology center with a 4-year history of skin rashes throughout the body, which was unresponsive to topical steroid treatment. The biopsy was taken, and the patient was diagnosed with MF CD 3 positive with spongiosis. The patient was treated with radiotherapy, whereby he received low dose total skin electron beam therapy (TSEBT) 12 Gy in 3 fractions at a daily dose of 4 Gy, followed by maintenance therapy of low dose Methotrexate and attained an excellent therapeutic response. CONCLUSION: Spongiosis is an infrequent presentation of MF. Low-dose TSEBT provides reliable and rapid reduction of disease burden in patients with MF, which could be administered safely multiple times during a patient's disease with an acceptable toxicity profile. Lack of tendency to perform skin biopsies and cost constraints in assessing multiple immunophenotypic markers lead to missing the diagnosis. Diagnosis and treatment of MF in resource-limited countries is challenging.