Monte Carlo study of SPECT in boron neutron capture therapy for a heterogeneous human phantom

Background: Boron neutron capture therapy [BNCT] is a binary radiotherapy combining biochemical targeting with neutron irradiation. However, monitoring the boron distribution is a fundamental problem in BNCT. Prompt gamma rays emitted by boron capture reaction can be used to address the issue

Materials and Methods: The general-purpose Monte Carlo toolkits Geant4 and MCNP were used for the simulations. A cubic phantom with soft tissue was used to study the prompt gamma emission during BNCT. The Chinese hybrid phantom with arbitrary tumors was constructed and used to acquire the 0.478 MeV prompt gamma rays in BNCT. Tomographic images were reconstructed with the maximum likelihood expectation maximization [MLEM] algorithm

Results: Comparison between MCNP and Geant4 showed a similar gamma rays emission rate in soft tissue. Up to 30 gamma ray peaks were found in the simulation, and 0.478 MeV prompt gamma ray from boron was clearly observed. The single brain tumor with variable diameter from 1 cm to 4 cm in the heterogeneous anthropomorphic phantom was each time found to be recognizable in the reconstructed image. Furthermore, in a patient with four tumors, the variable distance between the source and the tumors leads to a neutron attenuation thus resulting in an inhomogeneous number of prompt gammas

Conclusion: The SPECT system for a heterogeneous phantom in BNCT was simulated with Geant4. The results show that BNCT-SPECT is valid for the reconstruction of the boron capture interaction position for a heterogeneous patient

[Comparison between dexamethasone and tranexamic acid on postoperative edema and ecchymosis after rhinoplasty operation]

Rhinoplasty is one of the most popular plastic surgery in the world. Edema and ecchymosis are two expected consequences after any planned injuries such as surgery that extend time and cause to distress for the patients and their families. Several drugs [e.g. corticosteroid and eranexamic acid] and herbal extracts [e.g. arnica] are suggested for resolving this problem but there is no comparison between them yet. This study was undertaken to compare the potential benefits of dexamethasone with tranexamic acid on postoperative edema and ecchymosis after rhinoplasty. Determination of dexamethasone and tranexamic acid efficacy on edema and ecchymosis after rhinoplasty. This was a clinical trial cross sectional double blind study. Seventy rhinoplasty candidates were randomized in two groups. In addition to routine management and cold compress after operation, one group received dexamethasone and another group received tranexamic acid injection for both groups 1 dose of drug before and 3 doses per 8 hours after rhinoplasty. For measurement of edema and ecchymosis, we took digital photos from patients' face third day of postoperation. Then three colleagues who were blinded to assigned groups, scored edema and ecchymosis level with using 0-4 point standard scale. The alpha<0.05 is considered significant statistically. Nineteen men and fifty one women were enrolled. On postoperative day 3, there was no significant difference in the rating of preorbital ecchymosis among two intervention groups [p<0.15]. Also there was no significant difference for the edema rating among two intervention groups [p<0.12]. According to our results, no significant difference in postoperative edema and ecchymosis was detected among two groups. In regard to similar efficacy of both drugs to decrease edema and ecchymosis after rhinoplasty, we must select one of them according to the other effects of drugs

[Evaluation of body iron stores in non-over weight women with polycystic ovarian syndrome and its correlation with insulin resistance]

Polycystic ovarian syndrome [PCOS] is the most common cause of anovulation and hyperandrogenism, and obesity and insulin resistance are usually associated with this disease. Body iron stores are positively associated with glucose intolerance, type 2 diabetes mellitus, gestational diabetes and metabolic syndrome. It is reported that serum ferritin levels increase in obese women with PCOS. The aim of this study was to evaluate this relationship in women, neither overweight or obese, but suffering from PCOS. Fifty women with PCOS, without overweight, were selected based on the Rotterdam workshop criteria. After 12 hours fasting, serum ferritin, fasting blood sugar, cholesterol, triglycerides, HDL and insulin were measured and insulin resistance was calculated by HOMA-IR data was compared with that of 38 asymptomatic control subjects, matched for BMI and age. In the patient group, mean age was 27 +/- 5.78 years and mean BMI was 21.11 +/- 3.82 Kg/m2 mean serum ferritin in patients was 60.45 +/- 32.39, being 47.48 +/- 23.65 ng/mL in controls. Insulin resistance in patients was 2.61_0.91 and 1.74 +/- 0.72 in controls. Increases in serum ferritin, insulin and insulin resistance in patients were not statistically significant. There was no correlation between body iron stores and serum insulin level, insulin resistance and serum lipoproteins. Results showed that in non-overweight women with PCOS there is no significant increment of body iron stores

[Association of macroprolactinemia in patients presenting with hyperandrogenic symptoms]

Hyperprolactinemia is an exclusion criterion for the diagnosis of polycystic ovarian syndrome [PSOS] in women presenting with a combination of clinical or paraclinical hyperandrogenism, menstrual dysfunction and polycystic ovaries following ultrasonography; however hyperprolactinemia is common in hyperandrogenemic women. Macroprolactinemia may account for a significant number of hyperprolactinemic sera including hyperandrogenemic women and this may lead to unnecessary diagnostic and therapeutic procedures and false exclusion of PCOS. The aim of this study was evaluation of macroprolactinemia in women presenting with hyperandrogenemic symptoms and hyperprolactinemia. In a series of 200 hyperandrogenemic women, aged 14-40 years, presenting to the endocrine clinic of Ghaem Hospital between 2004-2006, serum prolactin was measured. If there was significant hyperprolactinemia [>35micro g/L], they were investigated for the presence of macroprolactinemia using the polyethylene glycol precipitation test. Thirty-eight [19%] patients had raised serum prolactin, of whom in 9, the rise was significant. Macroprolactinemia was detected in 5, and they were diagnosed with PCOS. In the remaining 4 patients, there was true hyperprolactinemia It is necessary to rule out macroprolactinemia in women presenting with hyperandrogenemic symptoms and hyperprolactinemia to prevent false exclusion of PCOS, expensive and unnecessary diagnostic procedures and inappropriate use of dopaminergic agonists