Diversity of medical dosimetry applicants and graduates
Diversity is a critical component in the advancement of human endeavor in science. Students who complete their education and training at diverse schools can serve patients from a wide range of ethnic backgrounds and promote cross-cultural competence. However, developing a diverse environment of professionals is a long-term effort which often takes generations to complete. Increasing awareness of underrepresented genders and/or minorities helps to establish goals for building a future of improved diversity. (Source: Medical Dosimetry)
Source: Medical Dosimetry - May 23, 2023 Category: Radiology Authors: Nishele Lenards Source Type: research
Improvement of target coverage using automated non-coplanar volumetric modulated arc therapy planning in stereotactic radiotherapy for cervical metastatic spinal tumors
This study aimed to compare dosimetric parameters for targets and organs at risk (OARs) between volumetric modulated arc therapy (VMAT) and automated VMAT (HyperArc, HA) plans in stereotactic radiotherapy for patients with cervical metastatic spine tumors. VMAT plans were generated for 11 metastases using the simultaneous integrated boost technique to deliver 35 to 40 and 20 to 25 Gy for high dose and elective dose planning target volume (PTVHD and PTVED), respectively. The HA plans were retrospectively generated using 1 coplanar and 2 noncoplanar arcs. (Source: Medical Dosimetry)
Source: Medical Dosimetry - May 16, 2023 Category: Radiology Authors: Shingo Ohira, Toshiki Ikawa, Shoki Inui, Naoyuki Kanayama, Yoshihiro Ueda, Masayoshi Miyazaki, Teiji Nishio, Masahiko Koizumi, Koji Konishi Source Type: research
Delivery of a VMAT technique with flattening filter (FF) and flattening filter free (FFF) mode for whole breast irradiation with five fractions (FAST-Forward trial)
To investigate the feasibility of volumetric modulated arc therapy (VMAT) delivery for whole breast irradiation with a 5-fraction regimen according to the FAST-Forward trial. Recently, we treated 10 patients with carcinoma of the left breast after breast conserving surgery. The dose prescription to the PTV was 26 Gy in 5 fractions. Treatment plans were produced using a VMAT technique with the Eclipse treatment planning system for 6 MV flattening filter (FF) and FF free (FFF) beams. Dose volume histograms (DVHs) for the PTV and the organs at risk (OARs), the ipsilateral lung and heart, were compared with the dose constraint...
Source: Medical Dosimetry - May 13, 2023 Category: Radiology Authors: Md Akhtaruzzaman, Md Jobairul Islam, Md Abdul Mannan, Mostafa Aziz Sumon, Martin Ebert Source Type: research
Assessing the impact of intrafraction motion correction on PTV margins and target and OAR dosimetry for single-fraction free-breathing lung stereotactic body radiation therapy
The objective of this research is to investigate intrafraction motion correction on planning target volume (PTV) margin requirements and target and organ-at-risk (OAR) dosimetry in single-fraction lung stereotactic body radiation therapy (SBRT). Sixteen patients (15 with upper lobe lesions, 1 with a middle lobe lesion) were treated with single-fraction lung SBRT. Cone-beam computed tomography (CBCT) images were acquired before the treatment, between the arcs, and after the delivery of the treatment fraction. (Source: Medical Dosimetry)
Source: Medical Dosimetry - May 8, 2023 Category: Radiology Authors: Clara J. Fallone, Clare Summers, Wladyslawa Cwajna, Alasdair Syme Source Type: research
Evaluation of the RadCalc collapsed cone dose calculation algorithm against measured data
This work describes the experimental validation of the RadCalc (Lifeline software Inc, Tyler) collapsed cone dose calculation algorithm against measured data for a range of scenarios. 6 MV photon beam data were measured in a large water tank on a Varian TrueBeam linear accelerator. These were input into the RadCalc software, in conjunction with head geometry and output calibration information, then used to create a collapsed cone beam model. The model performance was assessed by comparison against measurement, using a selection of homogeneous and inhomogeneous geometries not incorporated into the original beam model. (Sour...
Source: Medical Dosimetry - May 8, 2023 Category: Radiology Authors: Neil Richmond, Katherine Chester, Steven Manley Tags: Medical Physics Contribution Source Type: research
Simple and effective immobilization for radiation treatment of choroidal melanoma
At our institution, patients diagnosed with choroidal melanoma requiring external beam radiation therapy are treated with two 6 MV volumetric-modulated arcs delivering 50 Gy over 5 daily fractions. The patient is immobilized using an Orfit head and neck mask and is directed to look at a light emitting diode (LED) during CT simulation and treatment to minimize eye movement. Patient positioning is checked with cone beam computed tomography (CBCT) daily. Translational and rotational displacements greater than 1 mm or 1 ° off the planned isocenter position are corrected using a Hexapod couch. (Source: Medical Dosimetry)
Source: Medical Dosimetry - April 27, 2023 Category: Radiology Authors: Monique van Prooijen, Lily Chau, Grace Tsui, Valerie Kelly, Michael Holwell, Tony Tadic, Derek S. Tsang, Hatem Krema, Normand Laperriere Source Type: research
Dosimetric Effects of Dynamic Jaw Tracking and Collimator Angle Optimization in Non-Coplanar Cranial Arc Radiotherapy
In this study, the dosimetric effect of adding dynamic jaw tracking and automatic collimator angle selection in the optimization of single target cranial VMAT plans was investigated. Twenty-two cranial targets, previously treated with VMAT without dynamic jaw tracking and automatic collimator angle optimization (CAO) were chosen for replanning. (Source: Medical Dosimetry)
Source: Medical Dosimetry - April 22, 2023 Category: Radiology Authors: Cory Knill, Brian Loughery, Raminder Sandhu Tags: Medical Physics Contribution Source Type: research
Performance of auto-planning for VMAT hypofractionated left whole-breast irradiation with simultaneous integrated boost
Retrospective analysis of volumetric modulated arc therapy plans for hypofractionated left whole-breast irradiation with simultaneous integrated boost to assess the performance of the auto-planning (AP) engine. Fifteen treatment plans, produced using manual optimization planning approach (MP) were replanned using (AP) approach. Dose-volume parameters were defined to quantify the quality of concurrent treatment plans assessing target coverage and sparing organs at risk (OARs). The Wilcoxon Signed Rank test was used for statistical comparison of all results obtained from the use of the 2 approaches. (Source: Medical Dosimetry)
Source: Medical Dosimetry - April 20, 2023 Category: Radiology Authors: Antonella Bufacchi, Giorgio Arcangeli, Katia Pasciuti Source Type: research
Impact of dose distribution on rotational setup errors in radiotherapy for prostate cancer
This study aimed to assess the impact of rotational setup errors on the target volume's dose distribution during radiotherapy for prostate cancer. A 6D robotic couch was used to describe the rotational setup error, and the dosage change in the target volume was analyzed using the planning evaluation factors. Treatment plans for three-dimensional conformal radiotherapy (3DCRT), intensity-modulated radiotherapy (IMRT), and volumetric modulated arc radiotherapy (VMAT) were established after contouring the target volume and surrounding normal tissues on tomography obtained from the humanoid phantom. (Source: Medical Dosimetry)
Source: Medical Dosimetry - April 19, 2023 Category: Radiology Authors: Chulhwan Hwang Tags: Dosimetry Contribution Source Type: research
Impact of rectal gas on the planning target volume margin for pelvic bone and prostate matching in prostate cancer patients receiving volumetric-modulated arc therapy
We performed daily cone-beam computed tomography (CBCT) to determine the impact of rectal gas on the movements of prostate and seminal vesicles (SVs). We aimed to determine the relationship between planning target volume (PTV) margins and rectal gas. In 30 treatments of 15 prostate cancer patients, excessive rectal gas was removed and CBCT images were analyzed. Image registration between planning CT and daily CBCT images before and after rectal gas removal was performed for pelvic bone and prostate matching. (Source: Medical Dosimetry)
Source: Medical Dosimetry - April 18, 2023 Category: Radiology Authors: Yutaro Wada, Hajime Monzen, Naoko Ishida, Aritoshi Ri, Saori Tatsuno, Takuya Uehara, Masahiro Inada, Hiroshi Doi, Kiyoshi Nakamatsu, Makoto Hosono, Yasumasa Nishimura Source Type: research
Dosimetric analysis on computed tomography myelography based treatment planning in stereotactic body radiotherapy for spinal metastases
This study aimed to quantitatively evaluate the influence of enhanced contrast on the CT myelography image of the spinal cord and/or cauda equina in addition to the target volume in spine SBRT treatment planning. In total, 19 patients who had previously undergone spine SBRT were randomly selected. The rigid image registration accuracy of CT myelography that aligned with the treatment planning CT was evaluated by calculating the normalized mutual information (NMI) and Pearson's correlation coefficient for the vertebral landmarks. (Source: Medical Dosimetry)
Source: Medical Dosimetry - April 15, 2023 Category: Radiology Authors: Hidetoshi Shimizu, Yutaro Koide, Koji Sasaki, Yui Watanabe, Shoichi Haimoto, Takahiro Aoyama, Hiroyuki Tachibana, Tohru Iwata, Tomoki Kitagawa, Takeshi Kodaira Tags: Dosimetry Contribution Source Type: research
The spatial accuracy of ring-mounted halcyon linac versus C-arm TrueBeam linac for single-isocenter/multi-target SBRT treatment
This study quantifies the spatial positioning accuracy of 2 commercially available LINAC systems for SIMT treatment pertaining to the potential amplification of error as a function of the target's distance-to-isocenter. We compare the Ring-Gantry Halcyon LINAC equipped with the fast iterative conebeam-CT (iCBCT) for image-guided SIMT treatment, and the SBRT-dedicated C-Arm TrueBeam with standard pretreatment CBCT imaging. (Source: Medical Dosimetry)
Source: Medical Dosimetry - April 13, 2023 Category: Radiology Authors: Damodar Pokhrel, Richard Mallory, Mark E. Bernard Source Type: research
A case study of radiotherapy treatment for Dupuytren's contracture and Ledderhose disease
Dupuytren's contracture (DC) and Ledderhose disease (LD) are benign conditions of the fascia in the hands and feet respectively, which result in contracture of the digits. Radiation therapy has been proven effective in treating early-stage DC and LD; however, the problem is that there is a paucity of literature regarding radiation therapy treatment set-up for Dupuytren's and Ledderhose patients. The purpose of this case study was to demonstrate treatment set-up considerations of 6 and 9 MeV for DC and LD cases in radiotherapy (RT). (Source: Medical Dosimetry)
Source: Medical Dosimetry - April 12, 2023 Category: Radiology Authors: Paige Solie, Bryan Stump, Cortney Cashner, Nishele Lenards, Ashley Hunzeker, Sabrina Zeiler Tags: Dosimetry Contribution Source Type: research
A method for adjusting MLC leaf positions outside a reference region for VMAT plans in a commercial treatment planning system
In this study we developed an automatic method of adjusting leaf positions outside a reference region of interest (ROI) for VMAT plans generated in Pinnacle treatment planning system (TPS). The proposed method consisted of a Pinnacle script and a Python program. (Source: Medical Dosimetry)
Source: Medical Dosimetry - April 10, 2023 Category: Radiology Authors: Weijie Cui, Junjie Miao, Zhihui Hu, Ting Lu, Jianrong Dai Source Type: research
Hippocampal-sparing whole-brain radiotherapy under coplanar or noncoplanar VMAT
Whole-brain radiotherapy (WBRT) can alleviate symptoms in patients with brain metastases. However, WBRT may damage the hippocampus. Volumetric modulated arc therapy (VMAT) can achieve a suitable coverage of the target region and a more conforming dose distribution whereas decreasing the dose to organs-at-risk (OARs). Herein, we aimed to compare the differences between treatment plans utilizing coplanar VMAT and noncoplanar VMAT in hippocampal-sparing WBRT (HS-WBRT). Ten patients were included in this study. (Source: Medical Dosimetry)
Source: Medical Dosimetry - April 2, 2023 Category: Radiology Authors: Pin-Yi Chiang, Chao-Hsiung Hung, Chih-Chia Chang, Cheng-Yen Lee, Yu-Wen Wang, Yuk-Wah Tsang Source Type: research
