Showing 3 results for Dimension
Lotfinia I, Ghavami M, Haddadi K, Vahedi P,
Volume 68, Issue 2 (5-2010)
Abstract
Background: Pedicular screws are currently the gold standard of internal fixation of spinal column. Pedicular screws have their own complications, however the surgeon should be aware of morphometery of pedicles, as well as the anatomy of surrounding neural structures to minimize these risks. No national study has ever examined the physical characteristics of lumbar pedicles and this study is unique for this purpose.Methods: This study covers the patients undergoing lumbar spinal CT-scanning due to variable causes. 25 vertebrae were selected in either gender, 18 years or older and EFilm computer software was employed to measure different diameters of pedicle and the results were analyzed with p≤0.05 regarded as significant.Results: L5 pedicle was the widest (16.8 mm), while L1 was the narrowest (8.25 mm).this figure was 8.82, 10.48 and 12.86 mm for L2, L3, L4 respectively. Longitudinal depth of pedicle was 47.98, 48.68, 50.42, 48.32 and 47.8 mm for L1, L2, L3, L4, L5 respectively.Statistically significant differences were found between some dimensions detected in our study and similar studies.
Conclusions: The advantages of pedicular screws and rods to stabilize spinal column are well known. To avoid neurological complications, an understanding of anatomy and pedicle orientation is mandatory. The shape and diameters of pedicles are different base on races. Some differences were found in our study regarding pedicle dimensions.
Mahdi Aghili , Maryam Moshtaghi , Farhad Samiee , Ebrahim Esmati , Mahbod Esfahani , Hasan Ali Nedaee , Peiman Haddad ,
Volume 68, Issue 8 (11-2010)
Abstract
Background: The current standard of adjuvant management for gastric cancer after curative resection based on the results of intergroup 0116 is concurrent chemoradiation. Current guidelines for designing these challenging fields still include two-dimensional simulation with simple AP-PA parallel opposed design. However, the implementation of radiotherapy (RT) remains a concern. Our objective was to compare three-dimensional (3D) techniques to the more commonly used AP-PA technique.
Methods: A total of 24 patients with stages II-IV adenocarcinoma of the stomach were treated with adjuvant postoperative chemoradiation with simple AP-PA technique, using Cobalt-60. Total radiation dose was 50.4Gy. Landmark-based fields were simulated to assess PTV coverage. For each patient, three additional radiotherapy treatment plans were generated using three-dimensional (3D) technique. The four treatment plans were then compared for target volume coverage and dose to normal tissues (liver, spinal cord, kidneys) using dose volume histogram (DVH) analysis.
Results: The three-dimensional planning techniques provided 10% superior PTV coverage compared to conventional AP-PA fields (p<0.001). Comparative DVHs for the right kidney, left kidney and spinal cord demonstrate lower radiation doses using the 3D planning techniques (p<0.0001), the liver dose is higher (p=0.03), but is still well below liver tolerance.
Conclusion: Despite the department protocol using conventional planning, 3D radiotherapy provides 10% superior PTV coverage. It is associated with reduced radiation doses to the kidneys and spinal cord compared to AP-PA techniques with the potential to reduce treatment toxicity.
Reza Ghalehtaki, Mahdieh Razmkhah, Ali Kazemian, Mostafa Farzin, Samaneh Salarvand, Kasra Kolahdouzan, Ehsan Saraee,
Volume 82, Issue 10 (1-2025)
Abstract
Background: Gliomas are the most common primary brain tumors in adults, with low-grade gliomas making up 15% of cases. These slow-growing tumors often occur in young adults. Radiotherapy is one of the treatment options. New radiotherapy techniques like IMRT may reduce complications by sparing normal tissue. The study aims to determine which tumors benefit most from IMRT based on tumor location and size.
Methods: Patients diagnosed with low-grade glioma who were referred for treatment at the Cancer Institute of Imam Khomeini Hospital between September 2017 and September 2020 were included in this study. All patients underwent CT simulation with a thermoplastic mask for immobilization. A diagnostic MRI (performed within two weeks prior) was fused with the planning CT to define the target volume (GTV/CTV), with contours verified by a neuroradiologist. A doctor outlines the treatment volume and critical organs for both 3D and IMRT techniques. Radiotherapy physics experts design treatment plans using both techniques, which are then approved by a radiation oncologist. The treatment volume coverage and doses to critical organs are compared between the two techniques.
Results: Among 25 patients, 14 patients (56%) with single-lobe involvement, 7 (28%) with two lobes, and 4 (16%) with multifocal disease. Right-side brain involvement was seen in 32%, with the frontal lobe most affected. IMRT significantly reduced the mean and maximum cochlear dose on the treatment side in all patients. It also lowered the mean chiasma dose in those with both lobes involved and reduced cochlear dose on the opposite side in frontal lobe cases. No significant difference was found between the techniques for patients with multiple lobe involvement.
Conclusion: According to our study on 25 patients with low-grade glioma, it was shown that there is no clear difference between the two techniques. Given the young age and long survival of LGG patients, IMRT may be preferred when hearing preservation is a priority. Further studies with larger cohorts are needed to confirm these findings.
