Medical Dosimetry最新文献

{"title":"Rotating pods for stationary gantries.","authors":"Michael F Moyers, Wei Ren","doi":"10.1016/j.meddos.2025.02.006","DOIUrl":"https://doi.org/10.1016/j.meddos.2025.02.006","url":null,"abstract":"<p><p>The purpose of this project was, for light ion beams, to increase the available solid angle for beam entry when using stationary gantries to match that available with rotating gantries. Pods for chest, abdomen, and pelvis (CAP) and head and neck (HN) patients were developed to register, immobilize, and rotate patients with respect to robotic patient positioners. Ancillary devices were developed for moving and exchanging the pods for planning and treatment. Registration and immobilization techniques were enhanced to support the use of pods. For head patients, a beam entry solid angle greater than 2 pi was achieved. For chest, abdomen, and pelvis patients, a full 360^o rotation of the pods was obtained with the patient positioner providing additional rotation around a perpendicular axis but limited by collisions with the radiation head and imaging systems. The use of rotating pods with stationary gantries can achieve a similar beam entry solid angle to fully rotating gantries.</p>","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143812790","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":"Response to comments raised by a reader to the editor about our recently published paper \"Validation of ClearCalc for efficient patient specific QA\".","authors":"","doi":"10.1016/j.meddos.2025.02.004","DOIUrl":"https://doi.org/10.1016/j.meddos.2025.02.004","url":null,"abstract":"","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143796842","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":"Comment on \"validation of ClearCalc for efficient patient specific QA\".","authors":"Hinpetch Daungsupawong, Viroj Wiwanitkit","doi":"10.1016/j.meddos.2025.02.003","DOIUrl":"https://doi.org/10.1016/j.meddos.2025.02.003","url":null,"abstract":"","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143781312","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 superiority of deep inspiration breath hold-proton beam therapy for cardiac metastasis.","authors":"Dong-Jie Chen, Man Zhao, Jia-Wei Lu, Han Sun, Wei Jiang, Jun Liang","doi":"10.1016/j.meddos.2025.02.005","DOIUrl":"https://doi.org/10.1016/j.meddos.2025.02.005","url":null,"abstract":"<p><p>The purpose of this case report is to compare the dosimetric disparities between photon radiotherapy and intensity-modulated proton therapy (IMPT) with or without deep inspiration breath hold (DIBH) for cardiac tumors. We present a case involving a 66-year-old female with cardiac metastasis from thymic carcinoma. A total dose of 50Gy/50Gy_(RBE) in 25 fractions was administered to the cardiac metastases. Two simulation CT scans were obtained during free breath (FB) and DIBH. Dose distribution to target and organs at risk(OARs) was compared between intensity modulated radiotherapy (IMRT), volumetric modulated arc therapy (VMAT) and IMPT. All of the 6 plans satisfied treatment planning goals. The coronary artery (CA) Dmean (mean dose) was 28.32 Gy for IMRT-DIBH, 42.66 Gy for IMRT-FB, 26.44 Gy for VMAT-DIBH, 40.85 Gy for VMAT-FB, 27.71 Gy for IMPT-DIBH, and 39.51 Gy for IMPT-FB. The heart V50 (volume receiving ≥50 Gy) was 3.90 Gy for IMRT-DIBH, 6.71 Gy for IMRT-FB, 4.80 Gy for VMAT-DIBH, 6.63 Gy for VMAT-FB, 0.99 Gy for IMPT-DIBH, and 6.67 Gy for IMPT-FB, respectively. DIBH resulted in dose reductions in all OARs, particularly the heart and CA, compared to FB in all 3 planning techniques (IMRT, VMAT, and IMPT). Similarly, compared with IMRT or VMAT, IMPT reduced radiation doses to most OARs, including the heart and CA, in both FB and DIBH. DIBH-IMPT demonstrated superior dose coverage and OARs sparing in this thymic carcinoma patient with cardiac metastasis. Given the anticipated reduction in toxicities, IMPT with DIBH is preferred for cardiac tumors. The potential for broader application of IMPT with DIBH in clinical practice is currently being evaluated, and further studies are needed.</p>","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143743816","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":"Plan evaluation tool for spatially fractionated radiation therapy for unresectable large tumors via spatial biological effective dose modeling in combination therapy.","authors":"Josh Misa, James Knight, William St Clair, Damodar Pokhrel","doi":"10.1016/j.meddos.2025.02.002","DOIUrl":"https://doi.org/10.1016/j.meddos.2025.02.002","url":null,"abstract":"<p><p>We present the utility of a plan evaluation tool for a multi-course radiation treatment consisting of a highly heterogeneous SFRT plan followed by a course of curative radiation therapy for large and bulky unresectable tumors. For a more accurate plan assessment, this novel method calculates the voxelized biological effective dose (BED) spatially from each course and combines them into a single spatial BED distribution (s-BED). Ten previously treated head and neck (H&N) cancer patients with MLC-based 3D-conformal SFRT (15 Gy in 1 fraction) followed by a curative course of VMAT for 66-70 Gy in 33-35 fractions were retrospectively analyzed using this new s-BED method. The s-BED calculations were based on the standard linear-quadratic (LQ) model. Evaluations of mean BED using this s-BED method were compared to other methodologies that use each course's DVH, mean dose, and prescription dose. From this, tumor control probability (TCP) was calculated using these different methodologies. Lastly, doses to nearby organs at risk (OARs) were evaluated using the s-BED method and compared to each course's physical dose distribution. The OARs evaluated were the spinal cord, brainstem, optic pathway, cochlea, parotid glands, larynx, esophagus, and mandible. From the physical dose distributions, a s-BED distribution and a spatial EQD2 (s-EQD2) distribution were able to be calculated and visualized. The various methods of calculating mean BED using each course's dose prescription, mean dose, DVH, and from the s-BED resulted in varying mean BED: 121.8 Gy, 99.7 Gy, 88.3 Gy, and 100.6 Gy, respectively. In turn, this also gave varying predictions in tumor response: 100.0%, 98.2%, 92.3%, and 91.1%, respectively. Of the 8 H&N patients who received follow-up imaging, 7 (87.5%) had local tumor control. Reported toxicities of this cohort saw 2 cases of grade 3 toxicities (skin desquamation), 3 grade 1 toxicities (oral mucositis and odynophagia), and 1 grade 4 toxicity (necrotizing fasciitis). The composite s-BED distributions provided a means of better understanding the effective biological dose being delivered to both the target and nearby OARs spatially. Future utilization of this method during the treatment planning process may allow for more personalized treatment prescriptions for the SFRT course and the follow-up combination therapy, potentially enhancing therapeutic benefits in managing large and bulky unresectable tumors.</p>","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143694129","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":"Machine learning prediction for lung dose in locally advanced esophageal cancer using volumetric modulated arc therapy.","authors":"Shogo Kurokawa, Hiroyuki Okamoto, Tetsu Nakaichi, Shohei Mikasa, Satoshi Nakamura, Kotaro Iijima, Takahito Chiba, Hiroki Nakayama, Tairo Kashihara, Koji Inaba, Hiroshi Igaki","doi":"10.1016/j.meddos.2025.02.001","DOIUrl":"https://doi.org/10.1016/j.meddos.2025.02.001","url":null,"abstract":"<p><p>We developed machine learning (ML) models for predicting lung dose-volume histogram (DVH) metrics [V₅ _Gy, V₂₀ _Gy, and mean lung dose (MLD)] in locally advanced esophageal cancer volumetric modulated arc therapy and assessed the prediction accuracy of the models. Four ML models (linear regression, support vector machine, decision tree, and ensemble) were built with fivefold cross-validation of the predicted lung DVH metrics using a developed program by MATLAB R2022a. Eight explanatory variables were employed: gender, with/without simultaneous integrated boost and jaw tracking, age, height, weight, the ratio of the total irradiation angle to the total rotation angle of the gantry, and the ratio of the longitudinal length of the planning target volume overlapped with the whole lung to the length of the whole lung. To evaluate the prediction accuracy of the ML models, the differences and the Pearson correlation coefficients (r) between the predicted and planned doses were calculated. The mean ± standard deviation values of the planned lung doses of V₅ _Gy, V₂₀ _Gy, and MLD were 34.9 ± 15.2%, 11.9 ± 6.7%, and 7.2 ± 3.3 Gy, respectively. The differences for all models were -0.1 ± 8.0% (V₅ _Gy,), 0.1 ± 4.2% (V₂₀ _Gy), and -0.2 ± 1.7 Gy (MLD). The predicted lung doses were consistent with the clinically planned doses (V₅ _Gy [r = 0.7-0.8], V₂₀ _Gy [r = 0.6-0.8], and MLD [r = 0.7-0.9]), and there was no significant difference in the prediction accuracy among the ML models. These models can promptly evaluate and improve the quality of treatment plans by aiding patient-specific decision-making regarding lung-dose reduction before treatment planning.</p>","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143574474","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":"Quality assessment of automatically planned o-ring linac SBRT plans for pelvic lymph node and lung metastases, evaluating the optimal minimum target size.","authors":"Katerine Viviana Díaz Hernández, Sergejs Unterkirhers, Uwe Schneider","doi":"10.1016/j.meddos.2025.01.008","DOIUrl":"https://doi.org/10.1016/j.meddos.2025.01.008","url":null,"abstract":"<p><p>The purpose of this study is to assess the influence of Planning Target Volume (PTV) on the quality of automatic planned O-Ring Halcyon linac stereotactic body radiation therapy (SBRT) plans of pelvic lymph nodes (LN) and lung metastases and to evaluate an absolute PTV volume threshold as a plan quality prediction criterion. A total of 21 pelvic LN and 18 lung clinical treatment plans were replanned for Halcyon with unattended autoplanning. The prescription dose range was 26-40 Gy for LN and between 39-54 Gy for the lung in the mean 3 fractions. The mean/median PTV was 4.0/ 3.6 cm³ for LN and 4.9/ 4.3 cm³ for the lung. The criteria for the plan quality evaluation consisted of using dose metrics for conformity, spillage, and coverage and dose limits on healthy tissue assessment. A statistical study was performed based on systematic Mann-Whitney U test and cluster analysis to evaluate a PTV volume predictor threshold of plan quality. 95% (n = 20) LN and 100% (n = 18) lung plans met all tolerance criteria. For both cohorts of plans, a PTV threshold was determined, indicating a reduction of particular dose indices when below this threshold. Low risk of toxicity in healthy tissues was predicted. A PTV threshold of 4.0 cm³ was estimated as quality criteria in both cohorts of plans. The results of our study demonstrated the promising performance of Halcyon for pelvic and lung SBRT for small tumors, although plan-specific QA is required to verify machine performance during plan delivery.</p>","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143537906","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 comparison of HyperArc, conventional noncoplanar VMAT, and Halcyon-based coplanar VMAT in hippocampal-sparing whole-brain radiotherapy.","authors":"Zhen Li, Xin Yang, Huaqu Zeng, Jianrong Yu, Siming Zheng, Minying Li","doi":"10.1016/j.meddos.2025.01.007","DOIUrl":"https://doi.org/10.1016/j.meddos.2025.01.007","url":null,"abstract":"<p><p>To assess the dosimetric characteristics of HyperArc (HA), noncoplanar VMAT (NC-plan), and coplanar VMAT (HL3arc) in hippocampal-sparing whole-brain radiotherapy (WBRT). Twenty patients undergoing WBRT at our Hospital from June 2021 to March 2023 were selected. The dose parameters of organs at risk (OARs) were evaluated for all three groups, including D_100%, D_max, and D_mean of hippocampus, D_max to the lens, eyes, optic nerves, and chiasm, D_mean to the scalp and upper neck, and the dose volume parameters V_5Gy, V_10Gy, V_15Gy, V_20Gy for the upper neck. The D_98%, V_28.5Gy, D_2%, HI, CI, GI for PTV, as well as planning time, and beam-on time. HA had the lowest hippocampal D_max and D_mean. HA's scalp D_mean was lower than HL3arc (p = 0.007). HA's upper neck region D_mean and V_5-20Gy(cm³) were significantly higher than NC-VMAT and HL3arc. For PTV, HA's D₉₈ and V_28.5Gy were higher than NC-VMAT and HL3arc (p < 0.05). HA exhibited a significant advantage in terms of HI, CI and GI. The average planning times were 84.67, 17.30, and 20.40 minutes. Among the three treatment approaches, HA demonstrated the lowest bilateral hippocampal doses, but it exhibited the highest average dose and low-dose volume in the upper neck region, with the longest planning optimization process.</p>","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143473052","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":"Assessing proton plans with 3 different beam lines vs photon plans for early-stage lung cancer.","authors":"Tara Gray, Chieh-Wen Liu, Anna Maria Kolano, Jeremy Donaghue, Kevin Stephans, Gregory Videtic, Ping Xia, Jonathan Farr","doi":"10.1016/j.meddos.2025.01.006","DOIUrl":"https://doi.org/10.1016/j.meddos.2025.01.006","url":null,"abstract":"<p><p>To compare proton plans (IMPT) to VMAT plans and intercompare proton plans using 3 different spot sizes with robustness: cyclotron-generated proton beams (CPB) (σ: 2.7-7.0 mm), linear accelerator proton beams (LPB) (σ: 2.9-5.5 mm), and linear accelerator proton mini beams (LPMB) (σ: 0.9-3.9 mm) for the treatment of early-stage lung cancer. Twenty-two lesions from a total of twenty patients with early-stage lung cancer, originally treated with SBRT, were replanned using CPBs, LPBs, LPMBs, and VMAT using the same treatment planning system and dose calculation algorithm. The average intensity projected CTs (AIP-CT) were used for planning and 3D robust optimization was used for all proton plans. Conformity index (CI), homogeneity index (HI), R₅₀, lung V₂₀ _Gy, and mean lung dose were compared among all proton plan types and with VMAT plans. Set-up uncertainties of ±5 mm and ±3.5% range uncertainty were included in the IMPT robust optimization and evaluation, using V_100%Rx > 98% of the ITV. The Wilcoxon signed-rank test was used to evaluate statistical differences between VMAT plans and all proton plan types. When compared to VMAT plans, all proton plans generally show improvement in CI, HI, Lung V₂₀ _Gy, Mean lung dose, and R₅₀. The LPMB plans showed the most improvement from VMAT plans. Comparison between CPB and linear accelerator proton plans showed statistical significance (p < 0.05). R₅₀ and mean lung dose for the CPB, LPB and LPMB plans were 3.6 ± 0.9, 3.1 ± 0.8 and 2.6 ± 0.6; 2.2 ± 1.1 Gy, 1.9 ± 1 Gy and 1.6 ± 0.9 Gy, respectively (p < 0.05). The mean R₅₀ and mean lung dose from the VMAT plans were 4.1 ± 0.4 and 3.8 ± 2 Gy, respectively. The V₂₀ _Gy (%) of lung and mean lung dose were improved across all proton plans when compared with those of VMAT plans. When evaluated for robustness in the worst-case scenario at V_100%Rx of the ITV > 98%, average ITV coverage of 98.6 ± 0.3%, 98.6 ± 0.6%, and 98.9 ± 0.6% were achieved for CPB plans, LPB plans, and LPMB plans, respectively. With decreased spot size, the LPB and LPMB plans are excellent alternatives to VMAT and cyclotron-generated proton plans with reduced dose to normal tissue and improved plan quality for early-stage lung cancer treatments.</p>","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143426406","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":"Assessment of automated non-coplanar stereotactic radiosurgery planning in single isocenteric linac-based treatment for brain metastases with respect to planner's experience.","authors":"Meysam Tavakoli, Jarrett Bielata, Beth Ghavidel, Soumon Rudra, Baher A Elgohari, Benyamin Khajetash, Shada Wadi-Ramahi","doi":"10.1016/j.meddos.2025.01.002","DOIUrl":"https://doi.org/10.1016/j.meddos.2025.01.002","url":null,"abstract":"<p><p>One of the reasons for planning heterogeneity is lack of enough experience and recommendations on the quality of Linac-based stereotactic radiosurgery (SRS). In this study, our goal is to investigate the impact of planner's experience on the quality of Linac-based SRS plans for brain metastases (BMs) with varying levels of complexity. Specifically, to assess the impact of experience on the outcome of an automated noncoplanar treatment planning. A cohort of 120 patients with intracranial SRS plans, with a total of 633 BMs, was examined using VMAT delivery calculated with an available automated plan delivery system. Four planners with different levels of experience, ranging from under 1 year to over 5 years (Expert planner) of SRS planning, generated treatment plans. Dosimetric parameters and plan quality metrics were evaluated including: conformality index, homogeneity index, modulation factor, R_50%, total volume of brain receiving 12Gy, 6Gy, and 3Gy (V_12Gy, V_6Gy, V_3Gy) were assessed for each plan and compared with plan which was created by an expert planner with the highest planning experience. Experienced planners consistently produced acceptable plans, while less experienced one required revisions. Single BM cases showed minimal deviations in dosimetric parameters (under 10%) irrespective of planner experience. However, as the number and complexity of BMs increased, differences in plan quality became more pronounced. Moreover, expert planner's plans consistently outperformed others in terms of organs at risk sparing. This difference was particularly pronounced for cases involving the volume of healthy brain tissue. Our study underscores the critical role of planner's experience in the quality of Linac-based SRS plans using an automated planning. By standardizing and enhancing the planning process, the study aims to improve the quality of care for patients with multiple BMs, contributing to more efficient and effective treatments in the field of SRS.</p>","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143374945","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}