Background: Accurate voxel Phantom is needed for dosimetric simulation in radiation therapy for malignant tumors in female pelvic region. However, most of the existing voxel Phantoms are constructed on the basis of Caucasian or non-Chinese population. Materials and Methods: A Computational framework for constructing female pelvic voxel Phantom for radiation dosimetry was performed based on Chinese Visible Human (CVH) datasets. First, several organs within pelvic region were segmented from CVH datasets. Then, polygonization and voxelization were performed based on the segmented organs and a 3D Computational Phantom is built in the form of a set of voxel arrays. Results: The generated Phantom can be converted and loaded into treatment planning system for radiation dosimetry calculation. From the observed dosimetric results of those organs and structures, we can evaluate their absorbed dose and implement some simulation studies. Conclusion: A voxel female pelvic Phantom was developed from CVH datasets. It can be utilized for dosimetry evaluation and planning simulation, which would be very helpful to improve the clinical performance and reduce the radiation toxicity on organ at risk (OAR).

Introduction: This study aims to address the radiation exposure incurred by lung scintigraphy in pregnant patients suspected of pulmonary embolism and to investigate the dose variations due to different body habitus of the fetus. Material and Methods: In this respect, seven Computational models of pregnant women and fetus in three trimesters of pregnancy were used and Monte Carlo calculations were performed using Monte Carlo nparticle –, extended (MCNPX) code version 2. 6. 0 to assess absorbed dose coefficients. Time-integrated activities for three radiopharmaceuticals considered in this study were also extracted from the available reference biokinetic data. Results: Fetal dose coefficients (mGy/MBq) for three radiopharmaceuticals labeled with 99mTc were estimated for reference pregnant Phantoms at three trimesters of gestation and 10th, and 90th fetal growth percentiles were also considered during the last two trimesters. The results show that the fetal dose coefficients were 2. 09 × 10-2, 5. 71 × 10-3, and 4. 44 × 10-3 mGy/MBq for 99m Tc MAA, 8. 31 × 10-4, 8. 68 × 10-4, and 1. 27 × 10-3 mGy/MBq for 99m Tc Technegas, and 7. 85 × 10-3, 2. 42 × 10-3, and 2. 66 × 10-3 mGy/MBq for 99mTc DTPA aerosol, respectively. According to the results the factor of fetal body habitus adds variation to the fetal dose within ±, 15%. Conclusion: Considering one of the uncertainty components of fetal dose, that is the fetal body habitus, the dose variations were well below the safety threshold for the fetus (the threshold from ICRP Publication 84 for fetal cancer risk). Therefore, to check the safety of the diagnostic examination in terms of radiation dose to the fetus, it is sufficient to take into account the reference dose values in clinical practice.

Objective To determine the frequency of Phantom limb sensation (PLS) and Phantom limb pain (PLP) in children and young adults suffering landmine-related amputation.Materials & Methods All youths with amputation due to landmine explosions participated in this study. The proportions of patients with Phantom limb sensation/pain, intensity and frequency of pain were reported. Chi square test was used to examine the relationship between variables. Comparison of PLP and PLS between upper and lower amputation was done by unpaired t-test.Results There were 38 male and 3 female with the mean age of 15.8±2.4yr. The mean interval between injury and follow-up was 90.7±39.6 months. Twelve (44.4%) upper limb amputees and 11 (26.8%) lower limb amputees had PLS. Nine (33.3%) upper limb amputees and 7 (17.1%) lower limb amputees experienced PLP. Of 27 upper limb amputees, 6 (14.6%) and among 15 lower limb amputees, 6 (14.6%) had both PLS and PLP. One case suffered amputation of upper and lower limbs and was experiencing PLS and PLP in both parts. PLS had a significant difference between the upper and lower amputated groups.Significant relationship was observed between age of casualty and duration of injury with PLP.Conclusion Phantom limb sensation and pain in young survivors of landmine explosions appear to be common, even years after amputation.

Introduction: The determination of accurate dose distribution is an issue of fundamental importance in radiotherapy, especially with regard to the fact that the human body is a heterogeneous medium. Therefore, the present study aimed to analyze the density and isodose depth profiles of 6 MV beam in a SP34 slab‐wooden dust (pine) ‐SP34 slab (SWS) heterogeneous Phantom.Materials and Methods: The density of SP34 slab, wooden dust of pine, and thoracic region of 10 patients were calculated using computed tomography (CT) images. The depths of isodose lines were measured for 6 MV beam on the CT images of the chest, SP34 slab Phantom, and SWS Phantom. Dose calculation was performed at the depths of 2, 13, and 21 cm in both Phantoms. Furthermore, patient-specific quality assurance (QA) was implemented using both Phantoms.Results: The mean densities of the lung, SP34 slabs, and wooden dust were 0.29, 0.99, and 0.27 gm/cc respectively. The mean depths of different isodose lines in the SWS Phantom were found to be equivalent to those in actual patients. Furthermore, the percentage variation between the planned and measured doses was higher in the SWS Phantom as compared to that in the SP34 Phantom. Furthermore, the percentage variation between the planned and measured doses in patient‐specific QA was higher in the SWS Phantom as compared to that in the SP34 Phantom.Conclusion: As the findings indicated, the density and isodose depth profiles of the SWS Phantom were equivalent to those of the actual thoracic region of human.

Annually, many people are irradiated for diagnostic and therapeutic purposes. As-sessment of radiation dose and its related risks to patients are important issues in radiation protection dosimetry. The complex mathematical calculations of the absorbed and effective doses are now done with computers. The calculations are performed with the help of anthropomorphic Computational models of human body called Phantoms and Monte Carlo codes (MCNP). There are various types of Phantoms, yet the latest type is hybrid Phantom which has been introduced to the scientific community in recent years. Hybrid Phantom is the connection between mathematical and voxel Phantoms. They retain both the anatomic realism of voxel Phantoms and the flexibility of mathematical Phantoms. Using hybrid Phantoms, the absorbed doses can be determined for any patients before they are exposed to radiation. Then, the energy of the emitted particles and irradiation geometry can be determined for any special purposes. A hybrid Phantom is under construction for Iranian patients to be used in different applications such as testing new radiopharmaceuticals or cancer treatments with high LET radiation. Herein, we report on our findings.

Percutaneous renal biopsy is the most common method for obtaining renal tissue. In this article, the authors first explained how to make a cheap model of Phantom easily by sheep’, s kidney in a bowl filled with jelly. Then in the attached video, they showed how to find the ideal site (lower pole of kidney) and in real time, traced biopsy needle from jelly surface to kidney concomitant with ultrasound screen.