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.

Radiation therapists' perceptions of thermoplastic mask use for head and neck cancer patients undergoing radiotherapy at Ocean Road Cancer Institute in Tanzania: A qualitative study.

INTRODUCTION: A thermoplastic mask is the most widely used immobilization device for head and neck cancer patients undergoing radiotherapy. The radiation therapist is the staff responsible to prepare these masks and set-up the patients for treatment, a procedure that requires time, patience, and precision. An understanding of Radiation therapists' perceptions regarding thermoplastic mask use will help design interventions to address challenges encountered in its use. This study explored Radiation therapists' perceptions of thermoplastic mask use for head and neck cancer patients undergoing radiotherapy at Ocean Road Cancer Institute in Tanzania. MATERIAL AND METHODS: An exploratory qualitative study design was used to explore thermoplastic mask use for head and neck cancer patients undergoing radiotherapy. Semi-structured in-depth interviews were conducted, involving fifteen Radiation therapists from Ocean Road Cancer Institute in Tanzania between March and May 2021. A thematic analysis method was used to identify themes from data scripts. RESULTS: Four themes emerged that reflected radiation therapists' perceptions of thermoplastic mask use for head and neck cancer immobilization among patients undergoing radiotherapy. Emerged themes were (1) Perceived benefits and limitations of thermoplastic mask use, (2) Refresher training and supervision requirements for effective use, (3) Proper storage for quality maintenance, and (4) Increased financial support and proper budgeting. CONCLUSION: Participants perceived better patient immobilization with a thermoplastic mask use. However, too often recycling of thermoplastic masks and the long waiting time between thermoplastic mask preparation and treatment delivery limits their effective use. For efficient use of thermoplastic masks, there is a need for Radiation therapists' refresher training and proper supervision, improving the storage system and increasing financial support for procuring new thermoplastic masks.

Burden and risk factors for Schistosoma mansoni infection among primary school children: A quantitative school-based cross-sectional survey in Busega district, Northern Tanzania.

BACKGROUND: Intestinal schistosomiasis is one of the most common neglected tropical diseases in Tanzania. Despite massive praziquantel administration, data from Northern Tanzania have reported a prevalence of up to 93.2%. Because the disease is focal, depending on host, environmental and intermediate host factors, there is a need to acquire data in specific settings to better tailor interventions. Therefore, the study assessed the prevalence and factors associated with persistent transmission of intestinal schistosomiasis among school-age children in Busega district, Northern Tanzania. METHODS: A school-based cross-sectional study was conducted among 363 primary school children, randomly selected from school clusters in the Busega district. A single stool sample was collected from each child for S. mansoni ova and infection intensity examination using Kato-Katz. Factors related to intestinal schistosomiasis transmission were acquired through a questionnaire. A malacological survey was carried out to determine the Biomphalaria infectivity rate. Descriptive statistics and logistic regression analysis were conducted to analyse the association between schistosoma infection and factors related to transmission in this setting. RESULTS: The prevalence of S. mansoni infection was 41.3% (95% CI: 36.3-46.5), statistically significantly higher among the younger group aged less than 11 years (46.4% vs 35.3%, p = 0.032). The intensity of infection was heavy in 1.6% of participants, moderate in 9.6%, and light in 30.9%. Studying at Mwamayombo Primary School (AOR = 2.50, 95% CI: 1.12-5.60) was the only factor significantly associated with S. mansoni infestations. The snail intermediate host belonged to Biomphalaria sudanica species, whose infectivity rate was quantified as 0.97%, thus confirming ongoing transmission in the area. CONCLUSIONS: There was a high prevalence of S. mansoni infection among school-age children in the Busega district. The presence of the infected Biomphalaria sudanica in the area documents the persistent transmission of the disease, favored by low knowledge and negative attitudes among school-aged children. Hence, the need for multi-approach intervention for schistosomiasis prevention and elimination.