20 research outputs found

    Testicular Dose and Associated Risk from Common Pelvis Radiation Therapy in Iran

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    This study aimed to investigate testicular dose (TD) and the associated risk of heritable disease from common pelvis radiotherapy of male patients in Iran. In this work, the relation between TD and changes in beam energy, pelvis size, source to skin distance (SSD) and beam directions (anterior or posterior) were also evaluated. The values of TDs were measured on 67 randomly selected male patients during common pelvis radiotherapy using 1.17 and 1.33 MeV, Theratron Cobalt-60 unit at SSD of 80 cm and 9 MV, Neptun 10 PC and 18 MV, GE Saturne 20 at SSD of 100 cm at Seyed-Al Shohada Hospital, Isfahan, Iran. Results showed that the maximum TD was up to 12% of the tumor dose. Considering the risk factor for radiation-induced heritable disorders of 0.1% per Sv, an excess risk of hereditary disorders of 72 per 10000 births was conservatively calculated. There was a significant difference in the measured TD using different treatment machines and energies (P < 0.001). The TD at 100 cm SSD were much less than that for 80 cm SSD (P <0.001). The Pearson Correlation test showed that, as expected, there was a strong correlation between TD and patient's pelvis size (r = 0.275, P <0.001). Using the student's t-tests, it was found that, there was not a significant difference between TD and beam direction (P = 0.231). Iranian male patients undergoing pelvic radiotherapy have the potential of receiving a TD of more than 1 Gy which might result in temporary azoospermia. The risk for induction of hereditary disorders in future generations should be considered as low but not negligible in comparison with the correspondent nominal risk

    Testicular Dose and Associated Risk from Common Pelvis Radiation Therapy in Iran

    Get PDF
    This study aimed to investigate testicular dose (TD) and the associated risk of heritable disease from common pelvis radiotherapy of male patients in Iran. In this work, the relation between TD and changes in beam energy, pelvis size, source to skin distance (SSD) and beam directions (anterior or posterior) were also evaluated. The values of TDs were measured on 67 randomly selected male patients during common pelvis radiotherapy using 1.17 and 1.33 MeV, Theratron Cobalt-60 unit at SSD of 80 cm and 9 MV, Neptun 10 PC and 18 MV, GE Saturne 20 at SSD of 100 cm at Seyed-Al Shohada Hospital, Isfahan, Iran. Results showed that the maximum TD was up to 12% of the tumor dose. Considering the risk factor for radiation-induced heritable disorders of 0.1% per Sv, an excess risk of hereditary disorders of 72 per 10000 births was conservatively calculated. There was a significant difference in the measured TD using different treatment machines and energies (P < 0.001). The TD at 100 cm SSD were much less than that for 80 cm SSD (P <0.001). The Pearson Correlation test showed that, as expected, there was a strong correlation between TD and patient's pelvis size (r = 0.275, P <0.001). Using the student's t-tests, it was found that, there was not a significant difference between TD and beam direction (P = 0.231). Iranian male patients undergoing pelvic radiotherapy have the potential of receiving a TD of more than 1 Gy which might result in temporary azoospermia. The risk for induction of hereditary disorders in future generations should be considered as low but not negligible in comparison with the correspondent nominal risk

    Sensitivity analysis of Monte Carlo model of a gantry-mounted passively scattered proton system

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    PURPOSE: This study aimed to present guidance on the correlation between treatment nozzle and proton source parameters, and dose distribution of a passive double scattering compact proton therapy unit, known as Mevion S250. METHODS: All 24 beam options were modeled using the MCNPX MC code. The calculated physical dose for pristine peak, profiles, and spread out Bragg peak (SOBP) were benchmarked with the measured data. Track-averaged LET (LET RESULTS: For the physical dose distribution, the MCNPX MC model matched measurements data for all the options to within 2 mm and 2% criterion. The Mevion S250 was found to have a LET CONCLUSIONS: This study revealed the importance of considering detailed beam parameters, and identifying those that resulted in large effects on the physical dose distribution and LETs for a compact proton therapy machine

    Erythropoietin ameliorates genetamicin-induced renal toxicity: A biochemical and histopathological study.

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    BACKGROUND Investigations have attempted to modify the outcome of tubular injury by either ameliorating renal tubular damage or promoting tubular regeneration in the case of acute tubular necrosis. OBJECTIVES We investigated the protective effect of Eprex an erythropoietin analogue on tubular injury induced by gentamicin (GM). MATERIALS AND METHODS Forty male Wistar rats were randomly divided into four groups. In group 1,rats were served as a sham group. In group 2, rats were injected intraperitoneally with 100 mg/kg of GM for 10 consecutive days (positive control group) and then were sacrificed. In group 3, rats received GM for 10 days then Eprex 100U/kg was injected intraperitoneally for the next 10 days and then they were sacrificed at the day 20th. In group 4 rats were injected a combination of GM (80 mg/kg) and Eprex 100U/kg intraperitoneally for 10 days and then were sacrificed. RESULTS The results indicated that, Eprex prevented the increase in serum creatinine (Cr) and blood urea nitrogen (BUN). The effect of Eprex on damage score, showed that co-administration of GM and Eprex (group 3 and 4) reduced the kidney tissue damage compared to positive control group (P<0.05). This result indicat that Eprex potentially can reduce or prevent the kidney tissue damage. CONCLUSIONS Ameliorative effect of Eprex when the drug was given in combination with GM and also when the drug was applied after GM-induced tubular damage, revealed the renoprotective potency of Eprex. Eprex is a promising drug to prevent or attenuate tubular damage induced by GM or other nephrotoxic agents which act through the same mechanisms as gentamicin

    Oxford-MEST classification in IgA nephropathy patients: A report from Iran.

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    BACKGROUND There is a limited knowledge about the morphological features of IgA nephropathy (IgAN)in the middle east region. OBJECTIVES The objective of this study was to evaluate the spectrum of histopathological findings in IgAN patients at our laboratory. PATIENTS AND METHODS At this work, an observational study reported which was conducted on IgAN patients using the Oxford-MEST classification system. RESULTS In this survey, of 102 patients 71.6 % were male. The mean age of the patients was 37.7 ± 13.6 years. Morphologic variables of MEST classification was as follows; M1: 90.2 %, E: 32 %, S: 67 % also,T in grads I and II were in 30% and 19% respectively, while 51% were in grade zero. A significant difference was observed in segmental glomerulosclerosis (P=0.003) and interstitial fibrosis/tubular atrophy frequency distribution (P= 0.045), between males and females . Furthermore, it was found that mesangial hypercellularity was more prevalent in yonger patients. Moreover, there was a significant correlation between serum creatinine and crescents (P<0.001). There was also significant correlation of serum creatinine with segmental glomerulosclerosis (P<0.001). CONCLUSIONS Higher prevalence of segmental glomerulosclerosis and interstitial fibrosis/ tubular atrophy, as the two of, four variables of Oxford-MEST classification of IgAN in male patients further attests that male gender is a risk factor in this disease.In this study the significant correlation between serum creatinine and crescent was in an agreement with previous studies and suggests for the probable accomodation of extracapillary proliferation as a new variable in MEST system

    Thermal effects of laser-osteotomy on bone: Mathematical computation using maple

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    In recent years, interest in medical application of lasers especially as a surgical alternative is considerably increasing due to their distinct advantages such as non-contact intervention, bacteriostasis, less traumatization, minimal invasiveness, decreased bleeding and less heat damage. The present study aimed to evaluate the temperature changes and the consequent released thermal stress in cortical bone caused by an Erbium:yttrium aluminum garnet (Er:YAG) laser (Fideliss 320A, Fotona Inc., Deggingen, Germany) during osteotomy, using mathematical computation by means of Maple software, version 9.5 (Maplesoft, a division of Waterloo Maple Inc., Canada). The results obtained here were compared with the experimental measurements using Er:YAG laser in the osteotomy clinics. A bone slab with thickness of 1 mm was simulated in Maple software. Then, an Er:YAG laser emitting 100 μs pulses at a wavelength of 2940 nm were modeled. Two different clinical settings of the Er:YAG laser with 200 mJ and 400 mJ energies, both with 100 μs exposure and 500 μs silence were studied. To investigate the temperature distribution in the cortical bone, the time-dependent heat conduction equations were defined and solved in the Maple software. Finally, by defining the heat distribution function in the Maple, thermal stress in the bone was investigated. Results of the computations showed that, on the bone irradiated area (center of the bone surface) the maximum temperature rise was 0.8΀C and 1.6΀C, for 200 mJ and 400 mJ Er:YAG laser exposure, respectively. The temperature rise reached to its minimum at radial distances of 1.2 cm from the point of irradiated area for 200 mJ laser while it was 1.5 cm for 400 mJ laser. For 200 mJ laser the maximum derived radial (σrr ), axial (σzz ) and azimuthally (σθθ0) stress components were 0.20, 0.16 and 0.08 MPa, respectively. While, for 400 mJ laser the maximum derived σrr, σzz and σθθ stress components were 0.39, 0.31 and 0.16 MPa, respectively. These results confirm that use of 100 μs Er:YAG laser pulses with 500 μs silence at 200 and 400 mJ energies minimizes thermal tissue damage for the laser osteotomies, without continued water cooling (irrigation) on the exposed area

    Testicular Dose and Associated Risk from Common Pelvis Radiation Therapy in Iran

    No full text
    This study aimed to investigate testicular dose (TD) and the associated risk of heritable disease from common pelvis radiotherapy of male patients in Iran. In this work, the relation between TD and changes in beam energy, pelvis size, source to skin distance (SSD) and beam directions (anterior or posterior) were also evaluated. The values of TDs were measured on 67 randomly selected male patients during common pelvis radiotherapy using 1.17 and 1.33 MeV, Theratron Cobalt-60 unit at SSD of 80 cm and 9 MV, Neptun 10 PC and 18 MV, GE Saturne 20 at SSD of 100 cm at Seyed-Al Shohada Hospital, Isfahan, Iran. Results showed that the maximum TD was up to 12% of the tumor dose. Considering the risk factor for radiation-induced heritable disorders of 0.1% per Sv, an excess risk of hereditary disorders of 72 per 10000 births was conservatively calculated. There was a significant difference in the measured TD using different treatment machines and energies (P < 0.001). The TD at 100 cm SSD were much less than that for 80 cm SSD (P <0.001). The Pearson Correlation test showed that, as expected, there was a strong correlation between TD and patient's pelvis size (r = 0.275, P <0.001). Using the student's t-tests, it was found that, there was not a significant difference between TD and beam direction (P = 0.231). Iranian male patients undergoing pelvic radiotherapy have the potential of receiving a TD of more than 1 Gy which might result in temporary azoospermia. The risk for induction of hereditary disorders in future generations should be considered as low but not negligible in comparison with the correspondent nominal risk
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