Evaluation of oral mucositis, candidiasis, and quality of life in patients with head and neck cancer treated with a hypofractionated or conventional radiotherapy protocol: a longitudinal, prospective, observational study.

BACKGROUND: Due to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, recently, Radiotherapy (RT) protocols requiring fewer sessions (hypofractionated) have been used to shorten RT treatment and minimize patient exposure to medical centers, and decrease the risk of SARS-CoV-2 infection. METHODS: This longitudinal, prospective, observational study aimed to compare the quality of life (QoL) and the incidence of oral mucositis and candidiasis in 66 patients with head and neck cancer (HNC) who undergo a hypofractionated RT protocol (GHipo), total of 55 Gy for 4 weeks, or a conventional RT protocol (GConv), total of 66 - 70 Gy for 6 - 7 weeks. PURPOSE: To assess the incidence and severity of oral mucositis, the incidence of candidiasis, and QoL were evaluated using the World Health Organization scale, clinical evaluation, and the QLC-30 and H&N-35 questionnaires, respectively, at the beginning and the end of RT. RESULTS: The incidence of candidiasis did not show differences between the two groups. However, at the end of RT, mucositis had a higher incidence (p < 0.01) and severity (p < 0.05) in GHipo. QoL was not markedly different between the two groups. Although mucositis worsened in patients treated with hypofractionated RT, QoL did not worsen for patients on this regimen. CONCLUSIONS: Our results open perspectives for the potential use of RT protocols for HNC with fewer sessions in conditions that require faster, cheaper, and more practical treatments.

Monte Carlo simulation and dosimetry measurements of an experimental approach for in vitro HDR brachytherapy irradiation.

Irradiation of tumor cell lines is a useful way to investigate the effects of ionizing radiation on biological molecules. We designed an easy and reproducible approach for in vitro experimental high dose rate brachytherapy, which was simulated by a Monte Carlo code and dosimetrically characterized by experimental methods to evaluate the correspondence between planned doses and doses absorbed by the cells. This approach is an acrylic platform containing T25 tissue culture flasks and multiwell tissue culture plates. It allows nine parallel needles carrying an 192Ir source to irradiate the adherent cells. The whole system composed of the acrylic platform, tissue culture flasks and 192Ir source tracking was simulated by the Monte Carlo N-Particle transport code (MCNPX). Dosimetric measurements were taken by well ionization chamber and radiochromic films. There was a slight difference, averaging from 2% to 7%, between the MCNPX results and film dosimetry results regarding uniform radiation created by the source arrangement. The results showed different values for planned and measured doses in each cell culture plate, which was attributed to the non-equivalent water material used and to the lack of full scattering coming from the top of the platform. This last contribution was different for each tissue culture plate and an individual dose correction factor was calculated. The dose correction factor must be applied to match the planned dose and the actual doses absorbed by the cells. The designed approach is an efficient tool for in vitro brachytherapy experiments for most commercial cell culture plates.

Individualized threshold for tumor segmentation in 18F-FDG PET/CT imaging: The key for response evaluation of neoadjuvant chemoradiation therapy in patients with rectal cancer?

INTRODUCTION: The standard treatment for locally advanced rectal cancer (RC) consists of neoadjuvant chemoradiation followed by radical surgery. Regardless the extensive use of SUVmax in 18F-FDG PET tumor uptake as representation of tumor glycolytic consumption, there is a trend to apply metabolic volume instead. Thus, the aim of the present study was to evaluate a noninvasive method for tumor segmentation using the 18F-FDG PET imaging in order to predict response to neoadjuvant chemoradiation therapy in patients with rectal cancer. METHOD: The sample consisted of stage II and III rectal cancer patients undergoing 18F-FDG PET/CT examination before and eight weeks after neoadjuvant therapy. An individualized tumor segmentation methodology was applied to generate tumor volumes (SUV2SD) and compare with standard SUVmax and fixed threshold (SUV40%, SUV50% and SUV60%) pre- and post-therapy. Therapeutic response was assessed in the resected specimens using Dworak's protocol recommendations. Several variables were generated and compared with the histopathological results. RESULTS: Seventeen (17) patients were included and analyzed. Significant differences were observed between responders (Dworak 3 and 4) and non-responders for SUVmax-2 (p<0.01), SUV2SD-2 (p<0.05), SUV40%-2 (p<0.05), SUV50%-2 (p<0.05) and SUV60%-2 (p<0.05). ROC analyses showed significant areas under the curve (p<0.01) for the proposed methodology with sensitivity and specificity varying from 60% to 83% and 73% to 82%, respectively. CONCLUSION: The present study confirmed the predictive power of the variables using a noninvasive individualized methodology for tumor segmentation based on 18F-FDG PET/CT imaging for response evaluation in patients with rectal cancer after neoadjuvant chemoradiation therapy.

Effects on 18F-FDG PET/CT Brain Glucose Metabolism in Rectal Cancer Patients Undergoing Neoadjuvant Chemotherapy.

PURPOSE: Retrospective study of the effects of anticancer treatment on the brain metabolism of patients diagnosed with rectal cancer based on a large and homogeneous sample of 40 paired F-FDG PET/CT volumes taken from 20 patients. The results are compared to the ones presented by related works to help elucidating the mechanisms of neurotoxicity associated to a decrease in memory, learning and motor skills. PATIENTS AND METHODS: Twenty patients with rectal adenocarcinoma were scanned before and after neoadjuvant chemoradiation based exclusively on 5-fluorouracil and leucovorin. The sample was non-rigidly registered to a common template to allow for the comparison of regional metabolism. Statistical analysis was based on adjusted paired t-tests. RESULTS: The analysis primarily revealed a statistically significant decrease in the metabolism after neoadjuvant chemotherapy at the hypothalamus, putamen, head of the caudate, globus pallidus, red nucleus, substantia nigra, amygdala, cerebellum and the parahippocampal gyrus. The analysis also revealed smaller regions of increased metabolic activity at the middle temporal gyrus, precuneus of the parietal lobe and cuneus of the occipital lobe. CONCLUSIONS: The regions of decreased metabolism detected in the study are related to memory, learning and voluntary movement which is consistent with previous findings based on clinical studies and neuropsychological tests that report impairments on neurocognitive and motor skills associated to these therapies.

Individualized threshold for tumor segmentation in 18F-FDG PET/CT imaging: The key for response evaluation of neoadjuvant chemoradiation therapy in patients with rectal cancer? / Individualização na segmentação tumoral de imagens de 18F-FDG PET/CT: a chave para avaliação de resposta terapêutica neoadjuvante em pacientes com câncer retal?

Summary Introduction: The standard treatment for locally advanced rectal cancer (RC) consists of neoadjuvant chemoradiation followed by radical surgery. Regardless the extensive use of SUVmax in 18F-FDG PET tumor uptake as representation of tumor glycolytic consumption, there is a trend to apply metabolic volume instead. Thus, the aim of the present study was to evaluate a noninvasive method for tumor segmentation using the 18F-FDG PET imaging in order to predict response to neoadjuvant chemoradiation therapy in patients with rectal cancer. Method: The sample consisted of stage II and III rectal cancer patients undergoing 18F-FDG PET/CT examination before and eight weeks after neoadjuvant therapy. An individualized tumor segmentation methodology was applied to generate tumor volumes (SUV2SD) and compare with standard SUVmax and fixed threshold (SUV40%, SUV50% and SUV60%) pre- and post-therapy. Therapeutic response was assessed in the resected specimens using Dworak's protocol recommendations. Several variables were generated and compared with the histopathological results. Results: Seventeen (17) patients were included and analyzed. Significant differences were observed between responders (Dworak 3 and 4) and non-responders for SUVmax-2 (p<0.01), SUV2SD-2 (p<0.05), SUV40%-2 (p<0.05), SUV50%-2 (p<0.05) and SUV60%-2 (p<0.05). ROC analyses showed significant areas under the curve (p<0.01) for the proposed methodology with sensitivity and specificity varying from 60% to 83% and 73% to 82%, respectively. Conclusion: The present study confirmed the predictive power of the variables using a noninvasive individualized methodology for tumor segmentation based on 18F-FDG PET/CT imaging for response evaluation in patients with rectal cancer after neoadjuvant chemoradiation therapy.

Resumo Introdução: O câncer retal (RC) é uma doença de importância global, e o tratamento padrão para o câncer retal localmente avançado compreende quimiorradiação neoadjuvante seguida de cirurgia radical. Independentemente do uso extensivo da captação tumoral mais intensa do 18F-FDG (conhecida como SUVmax) como representativo do consumo glicolítico do tumor nas imagens de PET, há uma tendência para aplicar volume metabólico. Dessa forma, o objetivo do presente estudo foi avaliar um método não invasivo de segmentação tumoral utilizando a 18F-FDG PET para predizer a resposta à quimiorradioterapia neoadjuvante em pacientes com câncer de reto. Método: A amostra consistiu em pacientes com câncer retal em estádios II e III submetidos ao exame de 18F-FDG PET/CT antes e oito semanas após a terapia neoadjuvante. Foi aplicada uma metodologia de segmentação tumoral individualizada para gerar volumes tumorais (SUV2SD). A resposta terapêutica foi avaliada nos espécimes ressecados utilizando as recomendações do protocolo de Dworak. Várias variáveis foram geradas e comparadas com os resultados histopatológicos. Resultados: Dezessete (17) pacientes foram incluídos e analisados. Foram observadas diferenças significativas entre os respondedores (Dworak 3 e 4) e não respondedores para SUVmax-2 (p<0,01), SUV2SD-2 (p<0,05), SUV40%-2 (p<0,05), SUV50%-2 (p<0,05) e SUV60%-2 (p< 0,05). As análises ROC mostraram áreas significativas sob a curva (p<0,01) para a metodologia proposta, com sensibilidade e especificidade variando de 60% a 83% e 73% a 82%, respectivamente. Conclusão: O presente estudo confirmou o poder preditivo das variáveis utilizando uma metodologia não invasiva individualizada para segmentação tumoral baseada em imagens 18F-FDG PET/CT para avaliação da resposta em pacientes com câncer retal após tratamento com quimiorradiação neoadjuvante.

Papillary tumor of the pineal region.

Tumors of the pineal region are rare in adulthood, accounting for approximately 1% of intracranial neoplasms in this age range. Papillary tumor of the pineal region (PTPR) was first described by Jouvet et al. in 2003. In 2007, PTPR was included by the World Health Organization as a distinct entity in their new classification of central nervous system tumors. We report a case of PTPR, and undertake a literature review of this rare neuroepithelial neoplasm. Patients with PTPR need long-term follow up, and new cases should be well documented so that we can gain a better understanding of this neoplasm.