International Journal of Medical Physics, Clinical Engineering and Radiation Oncology

Journal Information
ISSN / EISSN : 21685436 / 21685444
Current Publisher: Scientific Research Publishing, Inc. (10.4236)
Total articles ≅ 251
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Soai Dang Quoc, Quang Bui Vinh, Cuong Bui Xuan, Toan Hoang Van, Truong Vu, Dang Quoc Soai, Bui Vinh Quang, Bui Xuan Cuong, Vu Truong
International Journal of Medical Physics, Clinical Engineering and Radiation Oncology, Volume 9, pp 1-13; doi:10.4236/ijmpcero.2020.91001

Abstract:Aims: This study compares data between the Field in Field planning and Wedge planning techniques to figure out which technique has better dose coverage and distribution for PTV, and, if using FiF technique for whole brain treatment, how many beams will have better plan. Methods: 56 patients, who need to radiate whole brain with 30 Gy/10 fractions, have been selected for this study. Four plans have been made for each patient (FiF1—one subfield per field plan, FiF2—two subfields per field plan, FiF3—three subfields per field plan, and a Wedge plan). Results: The results of Field in Field plans including Compare dose distribution on the transverse CT slice, plan evaluation using DVH, number MU of plan, Dmax, HI, HTCI, DmaxPTV, DmeanPTV. Volume of PTV with the dose over 105% prescribed dose, dose of organ at risk, and Quality Assurance (QA) plan, are better than those of Wedge plan. Conclusions: Plans using Field in Field technique has better coverage, is more homogeneous in dose distribution than plan using Wedge technique. When using Field in Field technique for whole brain radiotherapy, using three subfields per field has better result than two subfields per field and one subfield per field.
Ghada Mohammed Abd El Razeq, Mohammad A. M. Ahmed
International Journal of Medical Physics, Clinical Engineering and Radiation Oncology, Volume 9, pp 24-33; doi:10.4236/ijmpcero.2020.91003

Abstract:Introduction: Ovarian cancer is the commonest reason for death in females due to gynecologic malignancy around the world. In contrast to other gynecologic tumours, the definitive diagnosis is accomplished days after of the index surgery by the histopathology. Preoperative assessment based on conventional MRI is not accurate. Information is expanding increasing about the ability of new MRI modalities to assess ovarian mass. Aim of the study: To assess the ability of dynamic contrast-enhanced MRI (DCE–MRI), and Diffusion-weighted image (DWI) to describe uncertain ovarian masses. Patients and Methods: This is a retrospective study. Patients were referred from radio-diagnosis department and gynecology department of Qena faculty of medicine hospitals, South Valley University. Patients had uncertain adnexal masses at ultrasound. Magnetic resonance examination was doneutilizing 1.5 Tesla machine. The protocol included T1WI, T2WI, T1WI following contrast, and DWI. Results: We included 44 patients with different forms of complex cystic and solid ovarian masses. The final pathology of the ovarian masses was 18 benign, 4 borderline, and 22 malignant. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for DWI were 100%, 94.4%, 96.3%, 100%, and 97.7% respectively. The performance of DWI was higher than the conventional MRI and DCE-MRI. Conclusion: DCE-MRI and DWI have accepted ability to recognize malignant ovarian mass.
Shlomi Caduri, Itzhak Orion
International Journal of Medical Physics, Clinical Engineering and Radiation Oncology, Volume 9, pp 14-23; doi:10.4236/ijmpcero.2020.91002

Abstract:EGS5 Monte Carlo code is a general-purpose code for calculating photons and electrons transport for complex geometries in a wide range of energies. EGSnrc Monte Carlo code (BEAMnrc enclosed) was specially developed for medical physics usage, in particular for Linac modeling and dose calculations. Both EGS5 an EGSnrc were developed based on the former EGS4 code. For each of the codes, changes were made in the electron transport methods and in the geometrical utilities. Conformity between EGS5 calculation results and EGSnrc code results for Linac modelling was shown in recent work in our group. However, a large simulation run-time difference was found for the same conditions and statistical precision between these two codes. The EGS5 code took a longer period to obtain the same results compared to the EGSnrc code for Linac modelling. The electron transport in EGSnrc is based on the ESTEPE parameter, which is the maximum fractional energy loss per electron step. We investigated the ESTEPE parameter influence on the run-time and on the results accuracy. A set of variety simulations were performed using both codes in order to inspect the codes performance. We found that the EGSnrc run-time is strongly influenced by choosing different ESTEPE parameter values. While setting larger fractional energy losses per step, reduced simulation run-time was achieved. Hence, for optimal dose, one should define the optimal ESTEPE step-size parameter to achieve the desired dose results resolution. The use of the EGS5 code, based on the electron transport method improvements, is automatically adapted to the desired dose results quality without any user interference. Choosing the proper ESTEPE parameter for the use of EGSnrc for a given simulation resulted in similar run-time duration as with the use of EGS5. In conclusion, some cases that were tested in this study on the EGS5 and on the EGSnrc showed that the EGS5 is faster and more fluent to use between these two codes.
M. F. Uddin, R. Khatun, S. Akter, H. M. Jamil, A. N. Monika, M. A. Rahaman, R. P. Das, R. A. Sharmin, Ashikur Rahman, M. M. Ahasan
International Journal of Medical Physics, Clinical Engineering and Radiation Oncology, Volume 8, pp 1-8; doi:10.4236/ijmpcero.2019.81001

Abstract:High resolution (4 mm) tof PET-CT (positron emission tomography-computed tomography) from Philips of model Ingenuity TF is newly installed at Institute of Nuclear Medical Physics (INMP). 128 slice CT component incorporated with PET provides comparatively lower dose than the 511 keV annihilation photons associated with positron decay from PET scan. So, for designing shielding in our PET-CT facility, only 511 keV annihilation photons energy has been considered. The main objective of this paper is to show what measures have been taken to protect patients, occupational workers as well as environment from PET-CT radiation hazard through a cost effective design that satisfy the national regulatory demand. In this paper, AAPM (American Associations of Physicists in Medicine) Task group 108 analysis for PET and PET-CT shielding requirements is followed for our PET-CT facility shielding design. From theoretical calculation as shielding requirement, 1.1 cm Pb thickness or, 13 cm concrete thicknesses are found. Practically, all walls and ceiling are of 30.48 cm (1 foot) thick made of concrete with density 2.35 gcm-3 for more safety. As x-ray from CT is not taken into account for shielding analysis, Bangladesh Atomic Energy Commission (BAEC) conducted an extensive radiation survey at controlled, supervised and public area for CT. The report that is found meets the national regulatory requirements.
Tomohiro Shimozato, Keisuke Yasui, Hireto Kinou, Fumiaki Komatsu, Shimozato Tomohiro, Yasui Keisuke, Kinou Hireto, Komatsu Fumiaki
International Journal of Medical Physics, Clinical Engineering and Radiation Oncology, Volume 8, pp 193-203; doi:10.4236/ijmpcero.2019.84017

Abstract:Background and Aim: Irradiation methods such as double scattering method and spot scanning method have been used in proton beam treatment devices. In the scattering method, a ridge filter or a range modulation wheel is used to create a spread-out Bragg peak, but the distribution at the patient position may change due to positional deviation of the incident beam. Therefore, assessment of the incident position of the beam is very important even in the scattering method. To investigate the width and distribution of the proton beam before entering the RMW, a radiochromic film was installed at the outlet of the transport pipe and the entrance of the profile-monitoring detector. Methods: In this study, the distributions of the beam at the exit of the transport pipe and the entrance of the monitor detector were measured using films. The beam width was measured from the full width at half maximum of the profile obtained from the distribution. Measurements were conducted every month for 10 months. Results: Beams of widths ranging from 1.82 to 2.30 mm in the horizontal direction and 4.25 to 5.33 mm in the vertical direction were outputted from the exit of the transport pipe. Beams of widths ranging from 2.16 to 2.67 mm in the horizontal direction and 4.06 to 5.31 mm in the vertical direction were outputted from the entrance of the monitor detector. The maximum width fluctuation for 10 months was 0.55 mm in the horizontal direction and 1.26 mm in the vertical direction at the entrance of the monitor detector. Conclusions: The distribution was obtained before the proton beam was scattered by the scatterer, and then we propose a method to periodically measure and monitor the changes in the beam distributions every month.
Debnarayan Dutta, Sathiya Krishnamoorthy, Ganapathy Krishnan, Harikrishnaperumal Sudahar
International Journal of Medical Physics, Clinical Engineering and Radiation Oncology, Volume 8, pp 131-140; doi:10.4236/ijmpcero.2019.83012

Mostafa Elnagger, Hussein A. Motaweh, Kareman Zard
International Journal of Medical Physics, Clinical Engineering and Radiation Oncology, Volume 8, pp 163-174; doi:10.4236/ijmpcero.2019.83015

Abstract:Aim: The purpose of this study was to compare the dosimetric results of the techniques (3D-Brachytherapy and intensity-modulated radiotherapy IMRT) in patients with locally advanced cervical carcinoma (LACC). Method: There are 15 patients with locally advanced cervical carcinoma (LACC), after the completion of external beam radiotherapy (EBRT) for the whole pelvic irradiation 45 Gy/25 fractions, followed by 3D-Brachytherapy 24 Gy per weekly fractions and 36 Gy of IMRT per 18 fractions. Coverage of targets volume and doses received by normal tissue were compared in two techniques. Method: 15 patients of LACC treated with 3D-Brachytherapy were selected for this study. IMRT plans were also created for all the patients. 3D-Brachytherapy and IMRT plans were compared on the basis of target volume coverage, dose to Organs at risk (OAR’s), homogeneity index (HI) and conformity index (CI). Results: The results showed that D90% of HRCTV in the 3D-Brachytherapy was covered more than D90% of PTV in the IMRT of prescribed dose, the D2CC and the V60Gy values of Bladder and rectum were significantly lower than in 3D-Brachytherapy. The HI and CI in 3D-Brachytherapy were found better than IMRT. Conclusion: 3D-Brachytherapy significantly reduced the irradiated volume of OAR’s and improved dose coverage in tumor volume compared to that by IMRT.
Chunhui Han, Nayana Vora, Sean Zhang, An Liu, Jeffrey Y. C. Wong
International Journal of Medical Physics, Clinical Engineering and Radiation Oncology, Volume 8, pp 151-162; doi:10.4236/ijmpcero.2019.83014

Abstract:Purpose/Objectives: We aimed to report clinical effects on critical organ dose and cardiac toxicity from implementation of the deep inspiration breath-hold (DIBH) technique in post-operative extern-beam radiotherapy of patients with left-sided breast cancer, using longitudinal clinical data. Materials/Methods: We retrieved three groups of patients who received post-operative radiotherapy of left-sided breast cancer in our institution in recent years: Groups A and B consist of patients whose treatment did not include internal mammary nodes (IMN) and who were treated with the free breathing technique and with the DIBH technique, respectively, and Group C consists of patients whose radiotherapy included internal mammary nodes with the DIBH technique. Dose parameters for the heart and left lung were retrieved from the treatment plans. Radiation-induced cardiac risks were estimated using existing risk models. Results: The average heart dose was 2.65 ± 0.98 Gy, 1.10 ± 0.29 Gy, and 1.26 ± 0.25 Gy in Groups A, B, and C, respectively. The average heart volumes receiving at least 25 Gy were 7.10 ± 9.79 cc in Group A, 0.07 ± 0.22 cc in Group B, and 0.03 ± 0.08 cc in Group C. On average, the excessive risk of having ischemic heart disease was estimated to be 19.6%, 8.1%, and 9.3% in Groups A, B, and C, respectively. The mean left lung doses were 5.73 ± 1.86 Gy, 5.93 ± 1.55 Gy, and 9.13 ± 1.57 Gy in Groups A, B, and C, respectively. Conclusion: Implementation of the DIBH technique significantly lowered heart dose and decreased the ischemic heart disease risk in patients receiving post-operative radiotherapy for left-sided breast cancer, without significant increase in left lung dose.
Mukesh Kumar Zope, Deepali Bhaskar Patil, Angel Kuriakose, Aslam Rahman, Vinita Trivedi, Shekhar Kumar Keshri
International Journal of Medical Physics, Clinical Engineering and Radiation Oncology, Volume 8, pp 175-192; doi:10.4236/ijmpcero.2019.83016

Abstract:The advent of Intensity Modulated Radiation Therapy (IMRT) is rapidly changing the field of Radiation Oncology. IMRT has the potential to improve clinical implementation of highly conformal non-convex dose distributions. Nonetheless, a number of IMRT approaches including coplanar and noncoplanar beam techniques with 5 to 9 beams at different angles have been used in an effort to get the best dose distribution. The purpose of this study is to compare the dose to normal tissue and dose-limiting structures, conformity index, homogeneity index, number of monitor units required for the treatment of prostate cancer in 3 sets of five and seven beam IMRT plans and thus to select the best IMRT approach for patients with prostate cancer.
Azza N. Taher, Rasha A. Elawady, Amr Amin
International Journal of Medical Physics, Clinical Engineering and Radiation Oncology, Volume 8, pp 121-129; doi:10.4236/ijmpcero.2019.82011

Abstract:Purpose: To investigate if intensity modulated radiation therapy (IMRT) offers a better planning target volume (PTV) coverage and/or lower dose to normal thoracic structures in comparison to three dimensional conformal radiation therapy (3DCRT) in the treatment of mid and lower oesophageal carcinoma patients. Materials and Methods: A prospective study in the period from 2014 till 2015 was held in the radiation therapy department of the National Cancer Institute, Cairo University, in which 20 locally advanced or inoperable mid and lower oesophageal cancer patients were treated by chemo-radiation using 3DCRT technique. IMRT plans were generated for those 20 patients. The 3DCRT and IMRT plans were compared as regards PTV coverage and doses to critical organs at risk. Results: All plans had produced satisfactory PTV coverage with no significant differences noted. The lung V20 for both lungs in 3DCRT was 16.94% ± 4.2% which was increased to 21.42% ± 3.6% in IMRT (p = 0.017). The mean dose to the heart and V30 were higher in IMRT plans while the mean dose to the spinal cord was higher with 3DCRT plans, yet that didn’t reach a statistically significant level (p = 0.156). The dose delivered to the liver didn’t pose any difference between both techniques. Conclusion: 3DCRT remains to be a feasible cost effective treatment delivery option for mid and lower oesophageal cancer cases with a lower optimization and delivery time than that for IMRT. Moreover, that calls for further dosimetric studies and clinical trials to assess IMRT technique. In our study, IMRT using nine fields didn’t prove to be superior to 3DCRT.