Medical Dosimetry最新文献

{"title":"Directed Journal Reading (DJR) Program, Autumn 2025","authors":"","doi":"10.1016/j.meddos.2025.07.001","DOIUrl":"10.1016/j.meddos.2025.07.001","url":null,"abstract":"","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":"50 3","pages":"Page 291"},"PeriodicalIF":1.0,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144737961","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New Members List & Corporate Members List, Autumn 2025","authors":"","doi":"10.1016/j.meddos.2025.07.002","DOIUrl":"10.1016/j.meddos.2025.07.002","url":null,"abstract":"","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":"50 3","pages":"Page 292"},"PeriodicalIF":1.0,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144737962","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Feasibility of a robust and homogeneous volumetric modulated arc therapy based total body irradiation technique and analysis of dose rate using Elekta solutions.","authors":"Surendran Jagadeesan, Karthikeyan Kalyanasundaram, Majed Alghamdi, Moaz Mohammed, Raad Sweidan, Alaa Abdalqader, Yoginee Sonawane, Humaid Al-Shamsi, Ibrahim Abu-Gheida","doi":"10.1016/j.meddos.2025.06.003","DOIUrl":"https://doi.org/10.1016/j.meddos.2025.06.003","url":null,"abstract":"<p><p>Volumetric Modulated Arc Therapy (VMAT) for Total Body Irradiation (TBI) provides superior coverage, homogeneity, and organ sparing, leading to reduced toxicity. In this study, we present a VMAT-TBI technique delivered using Elekta solutions and report the average beam and lung dose rates. Nine patients were treated by VMAT-TBI technique. Treatment planning included VMAT for the upper body and VMAT or inverse optimized dynamic multileaf collimator (dMLC) plan using anteroposterior-posteroanterior (AP/PA) fields for the lower body. Plan robustness was evaluated for the 9 patients. Treatment log data was recorded with a sampling rate of 250 ms in the linear accelerator (linac) computer used for assessing the beam dose rates and delivery time. The average volume of all PTV receiving 95% of the prescription dose was 95.7 ± 1.3%. The mean heterogeneity index was 0.16 ± 0.03. The lung, kidney, and heart mean doses were 7.8 ± 0.2 Gy, 6.8 ± 0.3 Gy, and 6.8 ± 0.2 Gy, respectively, and the oral avoidance mean dose was 4.8 ± 0.6 Gy for myeloablative regimens. Robustness evaluation revealed the deviation of lung mean dose and the PTV maximum dose within 5% and 12.5%, respectively, with a 5 mm longitudinal isocenter shift. The mean instantaneous dose rate (IDR) for the thorax VMAT beam was 217 ± 26 MU/min. The average lung volume receiving above 20 cGy/min was 24.7 ± 8.2%. VMAT-TBI provides a homogeneous, robust, and selective organ-sparing treatment. Lung average dose rates can be reduced without any control applied to the IDR.</p>","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144745829","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reduction of mandibular doses using noncoplanar VMAT radiotherapy in the adjuvant management of locally advanced oral cavity squamous cell cancers.","authors":"Joseph Simms, Nathan Wilson, Christian Corcoran, Rachel Brooker","doi":"10.1016/j.meddos.2025.06.002","DOIUrl":"https://doi.org/10.1016/j.meddos.2025.06.002","url":null,"abstract":"<p><p>This treatment planning study aims to evaluate the feasibility of ncVMAT for patients receiving OCSCC radiotherapy and whether ncVMAT will help to achieve optimal mandible dose constraints. About 10 cases of ORN were identified in patients with OCSCC who received postoperative (C)RT between November 2014 and November 2017. Scoping for optimal planning technique was performed by comparing original plans with 5 alternative solutions. A noncoplanar solution with one full arc with couch at zero and 2 half-arcs with the couch rotated 45° for each was deemed optimal (minimizing mandibular dose whilst maintaining parotid sparing and avoiding excess dose to optics). Plans were re-optimized using this technique, attempting to improve mandibular V50Gy and D30%. Mean improvement in mandibular doses were most pronounced in Dmean and V50Gy. Applying optimal ncVMAT technique led to reduced mandibular V50Gy, maintained parotid sparing and improved PTV coverage. Mean reduction in mandibular V50 was modest (5.6%), 3 cases (all with centralized high dose PTV with floor of mouth/oral tongue primaries) showed dramatic improvements in V50Gy with reductions of 13.6%, 12.2% and 23.3%. Mandibular sparing can be achieved by ncVMAT without increasing parotid doses but with marginal increases to optic structures. This improvement may confer to reduced frequency of ORN if examined in prospective randomized trial. Dosimetric benefit seems to be greatest in those with central floor of mouth or oral tongue primary cancers.</p>","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144660887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Establishing a knowledge-based planning model for left-sided breast cancer patients receiving hypofractionated postmastectomy and regional nodal irradiation.","authors":"Shujun Zhang, Mei Chen, Yibin Zhang, Feifei Xu, Jinrong Xie, Gang Cai, Cheng Xu, Lu Cao, Jiayi Chen","doi":"10.1016/j.meddos.2025.06.001","DOIUrl":"https://doi.org/10.1016/j.meddos.2025.06.001","url":null,"abstract":"<p><p>We aimed to validate and evaluate a RapidPlan model for left-sided breast cancer patients receiving hypofractionated PM-RNI. This study included 89 patients with left-sided breast cancer who were enrolled in a clinical trial and received PM-RNI using IMRT. A RapidPlan KBP model was developed using 40 clinical IMRT plans treated at Institution A. The performance of the KBP model was assessed through internal validation and external validations at Institution A (n = 40) and Institution B (n = 9) by comparing the dosimetric indices and treatment efficiency between the initial plans and the re-optimized KBP plans. The KBP model's benefit for planners with different experience levels was evaluated by comparing the quality of non-KBP and KBP plans created by beginner, junior, and senior planners for 10 cases. With comparable target coverage, the KBP plans showed superior normal tissue sparing than the initial plans. On average, the mean heart dose was significantly reduced in the internal validation (p < 0.001), external validation at Institution A (p < 0.001), and increased in the validation at Institution B (but not significantly). In terms of dose conformality, KBP plans achieved a notable improvement in CI_50% during the external validation at Institution A (p = 0.006). Additionally, treatment efficiency was improved by the KBP model for all validation datasets, with a reduction of 2.8% to 8.8% in treatment time. The beginner planners benefit most from the KBP model, which improved plan quality by reducing the mean heart dose by 13.67 cGy (p = 0.020). The RapidPlan model for left-sided breast cancer receiving hypofractionated PM-RNI effectively spares organs and increases IMRT treatment efficiency. We also demonstrated that RapidPlan helps transfer planning skills from senior planners to beginner planners, thus improving the consistency of complex IMRT plans.</p>","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144621003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Collimator angle selection for prostate and lymph node volumes on the Varian halcyon machine.","authors":"Laura E O'Connor, Marissa R Pringle, Aubrey Buskerud, Nishele Lenards, Ashley Hunzeker, Matt Tobler","doi":"10.1016/j.meddos.2025.05.005","DOIUrl":"https://doi.org/10.1016/j.meddos.2025.05.005","url":null,"abstract":"<p><p>Volumetric modulated arc therapy (VMAT), in conjunction with the split-jaw technique, has been widely used on TrueBeam linear accelerators to enhance dose conformity and mitigate the physical limitations of multileaf collimators (MLCs) when treating large, complex volumes. A new linear accelerator from Varian called the Halcyon does not have jaws and poses challenges in treating such volumes due to its unique MLC configuration. The goal of this study was to determine collimator angles effective in sparing organs at risk (OAR) and improving plan conformity for prostate and pelvic lymph node volumes exceeding 20 cm in length. Two VMAT plans (Plan A and B) were created. Plan A utilized departmental-standard collimator angles of 5°, 355°, 85°, and 90°, whereas Plan B was based on the work of Cozzi et al. and used collimator angles 20°, 45°, 340° and 90°. It was hypothesized that Plan A would reduce the volume of rectum and bladder receiving 40 Gy (V40) and volume of small bowel receiving 15 Gy (V15) by > 5% and achieve a conformity index closer to 1.0. Fourteen patients were retrospectively analyzed, and the 2plans were compared. The results showed no statistically significant differences in OAR sparing or conformity between the plans. Although researchers offered valuable insights into collimator angle selection for complex volumes on the Halcyon, future studies with larger sample sizes or other collimator angles may help refine treatment planning strategies.</p>","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2025-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144565376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Target specific collimation within a VMAT trajectory delivery for stereotactic radiosurgery.","authors":"Jun Hao Phua, Glen Yongjie Mok, Lloyd Kuan Rui Tan, Sung Yong Park, James Cheow Lei Lee, Hong Qi Tan","doi":"10.1016/j.meddos.2025.05.007","DOIUrl":"https://doi.org/10.1016/j.meddos.2025.05.007","url":null,"abstract":"<p><p>Volumetric modulated arc therapy (VMAT) is the standard of care for stereotactic treatments. During a VMAT delivery, using a single collimator angle throughout a continuous arc may be suboptimal due to variations in the target's shape in the Beam Eye's view (BEV). This work proposes a VMAT optimization method which segments a single continuous arc to allow for varying collimator angle to achieve an efficient delivery and Monitor Unit (MU) utilization. Thirteen retrospective stereotactic radiosurgery (SRS) and stereotactic radiotherapy (SRT) patient plans with irregularly shaped targets were used in this study. The targets were mainly cavity and meningioma due to the irregular shapes. These cases were planned originally using the Eclipse treatment planning system (TPS). These plans were then replanned with rotated collimators at specific points in each VMAT arc, where the shape of the target was deemed to have changed extensively in the BEV. The start and end gantry angles of the trajectory followed the initially approved clinical plan. The resulting plans were compared with the original clinical plans using the mean aperture ratio, total plan monitor unit (MU), total beam delivery time, patient specific quality assurance (PSQA) results and the plan dosimetric metrics. These plans were delivered using Truebeam STx with HDMLCs and PSQA was measured using the Sun Nuclear SRS MapCheck with the gamma passing rate (GPR) criteria of 3%/2 mm, 2%/2 mm, 2%/1 mm, and 1%/1 mm. The replans achieved a 15.1% reduction in MUs while maintaining the target coverage. The organ-at-risk (OAR) doses showed no significant improvement when using this approach. The beam-on time for SRS plans decreased by 20% compared the clinically approved plan, while the SRT plans showed a 5% time savings. The gamma passing rate (GPR) yielded at least 99% for 2%/1 mm, and 100% for 2%/2 mm for both the clinically approved plans and the replans, respectively. There was no statistically significant difference in GPRs across all criteria and in the plan dosimetric metrics for target and normal tissues. These results show that the proposed optimization approach improves delivery efficiency in terms of both delivery time and MU reduction.</p>","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144512645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Clinical efficacy of AI in lung SABR planning: A comparative retrospective analysis.","authors":"Kylie Unicomb, Shamira Cross, Sean White, Kevin Vantilburg, Gary Low, Roland Yeghiaian-Alvandi","doi":"10.1016/j.meddos.2025.05.008","DOIUrl":"https://doi.org/10.1016/j.meddos.2025.05.008","url":null,"abstract":"<p><p>This study evaluated the effectiveness of an integrated Artificial Intelligence (AI) planning tool in a lung stereotactic ablative body radiotherapy (SABR) planning workflow. The aim was to determine whether the AI planning tool would facilitate the generation of consistent high-quality plans while simultaneously improving treatment plan efficiency. The study compares clinically treated planner derived lung SABR plans with AI-generated. Nineteen cases planned with traditional planner derived techniques which make up the control cohort human, were re-planned using AI to determine the efficiency and quality of AI generated plans. The study derived a set of AI criteria to create the AI cohort of plans, and further refinement with an additional optimization created AI + human cohort. Each plan was assessed using departmental criteria, including time efficiency, to determine plan quality. The best plans, chosen after a blind review by the treating RO, were documented and analyzed to demonstrate the effectiveness of AI assistance in Lung SABR planning. Ethics approval was given for this study at a local health district level. Across 19 patients, the human cohort showed a total of 3.3% criteria unmet, which dropped to 2.6% for AI assisted plans in the AI cohort. The percentage of unmet goals was further reduced to 1.84% after the addition of manual planner input in AI + human cohort. All plans selected by the RO in the blind review were produced using AI + human input, and the average time taken to produce AI assisted plans was 1.08 hours. The study demonstrates that AI, in conjunction with human expertise, significantly enhances the efficiency and quality of lung SABR plans for patients, with quality confirmed through blinded evaluation.</p>","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144512644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The influence of average electron density assignment on dose accuracy in MR-guided radiotherapy of rectum cancer.","authors":"Lingling Yan, Xuejie Xie, Yingjie Xu, Jianrong Dai","doi":"10.1016/j.meddos.2025.05.006","DOIUrl":"https://doi.org/10.1016/j.meddos.2025.05.006","url":null,"abstract":"<p><p>To study the impact of assigning average electron density on the dose accuracy of patients in adapt to shape (ATS) workflow of MR-guided adaptive radiotherapy (MRgRT). Ten rectum cancer patients, who underwent treatment with MRgRT, were included for this study. For each patient, 2 plans were created. The first plan, referred to as the average electron density (AVED) plan, was generated using bulk anatomical average density method based on anatomical contours derived from the CT image. The second plan, equivalent to the actual electron density (ACED) plan, was recalculated using the actual electron density while maintaining the same segment shapes and monitor units as the AVED plan. Consequently, the ACED plan represents the actual adaptive dose. Various parameters, including the dose conformity index (CI), homogeneity index (HI), as well as the dose to the planning target volume (PTV) and organs at risk (OARs), were analyzed. Additionally, the dose verification of the ACED plans was conducted using an MR-compatible ArcCHECK phantom. The gamma passing rate of the ACED plan in comparison to the AVED plan was calculated using 3-dimensional gamma analysis software. In the ACED plan, compared with the AVED plan, the coverage of prescribed dose in PTV was significantly low (p < 0.05), with the difference of 2.11% and PTV exhibited poorer values for both the HI and CI (p < 0.05). Additionally, the V₅₀ of colon, mean dose of bladder, left femur and right femur were significantly low (p < 0.05) in the ACED plans. The gamma pass rates for ACED plans exceeded 90% (ArcCHECK vs TPS) under 2 mm/3% and 2 mm/2% criteria with a 10% dose threshold. Compared to AVED plans, ACED plans achieved average pass rates of 99.39% ± 0.34% and 97.92% ± 0.65%, respectively. When using average electron density for dose calculations in MRgRT of rectum cancer, it is essential to note that there can be discrepancies between the calculated and actual doses, particularly in homogeneity of PTV.</p>","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144499004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dosimetric evaluation of adaptive radiotherapy in the treatment of head and neck cancer.","authors":"Burçin Hazeral, Yusuf Ziya Hazeral, Celil Cüneyt Ebruli, Volkan Semiz, Mustafa Esassolak","doi":"10.1016/j.meddos.2025.05.002","DOIUrl":"10.1016/j.meddos.2025.05.002","url":null,"abstract":"<p><p>The objective of this study is to determine the optimal timing and frequency of adaptive radiation therapy (ART) for patients diagnosed with nasopharyngeal and laryngeal cancer who experience anatomical and weight changes during radiation therapy (RT). Thirty patients who exhibited weight changes underwent repeat CT scans on the 10th, 15th, 20th, and 25th treatment days after the initial treatment CT scan. Weight measurements were recorded, and ART plans were implemented over 4 weeks. A total of 150 treatment plans were generated and analyzed based on 16 ART scenarios. Weighted cumulative dose summations were calculated, with the initial plan (iplan) serving as the reference dose distribution. Each ART plan scenario and the iplan were assessed dosimetrically, with statistical results and box plots generated for all critical structures and organs at risk (OARs). On average, weight loss was 9.31% over the treatment period. A reduction in ART applications resulted in decreased planned target volume (PTV) coverage, conformity number (CN), and homogeneity index (HI) for both patient groups. In both groups, median OAR values in ART scenarios were within the acceptable range, except in the spinal cord figures. Increasing the number of ART sessions improved PTV and OAR values. ART evaluations should be individualized based on patient-specific anatomical changes. ART should be considered when a 4.00% or greater weekly weight change is detected. Increasing the number of ART administrations improves cumulative weighted dose sums by bringing dose distributions closer to the iplan.</p>","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144340574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}