Evaluation of the preventive effect of dexpanthenol in radiation injury by lung perfusion scintigraphy: a preclinical experimental model of radiation injury.

AIM: The aim of this study was to show the preventative effects of dexpanthenol in radiation injuries caused by radiotherapy (RT) through the use of lung perfusion scintigraphy in the pre-RT and post-RT periods. MATERIALS AND METHODS: Six male New Zealand rabbits (5-6 months of age and ∼2.5-3 kg in weight) were the used in this study. The animals were subjected to Tc-macroaggregated albumin lung perfusion scintigraphy in the pre-RT and post-RT (i.e. 2 weeks after treatment) periods. The scintigraphies were performed with the same dose by the same staff and the methodology used the same acquisition parameters. The rabbits were divided into two groups: group I (administered RT only) and group II (also administered intramuscular 500 mg dexpanthenol injections for 14 consecutive days after RT). Quantification was performed to compare the groups and the quantification variables were compared using a paired samples t-test, with P value less than 0.05 considered to be statistically significant. Histopathological analysis was also carried out. RESULTS: The post-RT scintigraphies indicated a decrease in the counts in both lungs, suggesting early post-RT injury. The difference between the counts obtained from both lungs in groups I and II was significantly different and favoured group II. Histopathological results confirmed the scintigraphy results. CONCLUSION: It is possible to estimate post-RT changes in the early period (in contrast to previous data) by lung perfusion scintigraphy. Dexpanthenol may also reduce the effects of RT to a degree. Although this is the first study to report the preventive effects of dexpanthenol on RT injuries, further studies are warranted in this area.

Twenty four hour imaging delay improves viability detection by Tl-201 myocardial perfusion scintigraphy / Atraso de imagem de 24 horas melhora a viabilidade de detecção por cintilografia de perfusão miocárdica Tl-201

OBJECTIVE: Since twenty-four-hour imaging by Tl-201 myocardial perfusion scintigraphy has been introduced as an effective additional procedure, the aim of this study was to compare this method's result with only rest redistribution procedure in the diagnosis of myocardial viability. METHODS: Thirty patients (Seven female, 23 male; mean: 59.8 ± 10.7, 55.8-63.8 years old) with diagnosis of coronary artery disease were involved in this study. All patients had anamnesis of previous myocardial infarction and/or total occlusion of any main artery in the coronary angiography. Myocardial perfusion scintigraphy with Tl-201 with rest four hour (early) redistribution and 24 hour delayed redistribution protocol were performed to all of the patients. The images were evaluated according to 17 segment basis by an experienced nuclear medicine physician and improvement of a segment by visual interpretation was considered as viable myocardial tissue. RESULTS: Viability was found at 52 segments in the early redistribution images and additional 18 segments in the 24 hour delayed redistribution images on segment basis in the evaluation of 510 segments of 30 patients. On per patient basis, among the 26 patients who had viable tissue, 14 (54%) had additional improvement in 24 hour delayed images. Three (12%) patients had viable tissue in only 24 hour delayed images. CONCLUSION: Delayed imaging in Tl-201 MPS is a necessary application for the evaluation of viable tissue according to considerable number of patients with additional improvement in 24 hour images in our study, which is restricted to the patients with myocardial infarct.

OBJETIVO: Dado que a cintilografia Tl -201 24 horas de imagens por perfusão miocárdica foi introduzida como um procedimento adicional efetivo, assim, o objetivo deste estudo foi comparar os resultados deste método com o procedimento único de redistribuição no diagnóstico de viabilidade miocárdica. MÉTODOS: Trinta pacientes (Sete mulheres, 23 homens, média: 59,8 ± 10,7, 55,8-63,8 anos) com diagnóstico de doença arterial coronariana foram avaliados neste estudo. Todos os pacientes tinham anamnese de infarto do miocárdio e/ou oclusão total de uma artéria principal na cinecoronariografia. Cintilografia de perfusão miocárdica com protocolo de Tl-201 em repouso, redistribuição quatro horas (início) e redistribuição tardia 24 horas foi realizada em todos os pacientes. As imagens foram avaliadas de acordo com a base de 17 segmentos por um médico com experiência em medicina nuclear e melhoria de um segmento por interpretação visual foi considerado como tecido miocárdico viável. RESULTADOS: A viabilidade foi encontrada em 52 segmentos de redistribuição das imagens iniciais e 18 segmentos adicionais nas imagens de redistribuição tardias de 24 horas baseadas em segmento, na avaliação de 510 segmentos de 30 pacientes. Em termos de pacientes, entre os 26 pacientes que tinham tecido viável, 14 (54%) apresentaram melhora adicional em imagens tardias de 24 horas. Três (12%) pacientes tiveram tecido viável apenas em imagens tardias de 24 horas. CONCLUSÃO: A imagem tardia em TL- 201 MPS é uma aplicação necessária para a avaliação do tecido viável de acordo com o número considerável de pacientes com melhora adicional em imagens de 24 horas em nosso estudo, o qual é restrito aos pacientes com infarto do miocárdio.

Bone scan or (18)f-fluorodeoxyglucose positron emission tomography/computed tomography; which modality better shows bone metastases of breast cancer?

BACKGROUND: In this multicenter study, we aimed to compare concurrent (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) and bone scan results of breast cancer patient. PATIENTS AND METHODS: 162 patients with breast cancer (158 female, 4 male; mean age 50.6 years) were included in the study. FDG PET/CT examination was performed in all patients, and concurrent bone scintigraphy in 68 patients. The results of FDG PET/CT and bone scan were compared. RESULTS: 132 of the 162 patients were operated on because of breast cancer. 89 patients had metastasis, and 4 had recurrent disease according to FDG PET/CT results. Metastatic sites in order of frequency were lymph nodes, bone, lung, liver, adrenal gland, local skin or muscle, brain, and peritoneum (peritonitis carcinomatosa). The sensitivity, specificity, accuracy, and negative and positive predictive value of bone scintigraphy versus FDG PET/CT were 96 vs. 100%, 100 vs. 98%, 100 vs. 83%, 100 vs. 100%, and 90 vs. 100%, respectively. CONCLUSION: Although the 2 modalities were in concordance with each other, in 5 (21%) cases, FDG PET/CT could not show bone metastasis which were detected on bone scintigraphy. Hence, bone scintigraphy was superior to FDG PET/CT in the determination of bone metastasis derived from breast cancer. However, FDG PET/CT should be considered for soft tissue metastasis.