Medical Dosimetry最新文献

{"title":"Effects of axillary dose restriction on plan quality and acute radiation dermatitis in breast cancer radiotherapy.","authors":"Meizhen Shen, Meizhu Shen, Ying Mo, Chunming Lin, Jian Qin","doi":"10.1016/j.meddos.2024.12.005","DOIUrl":"https://doi.org/10.1016/j.meddos.2024.12.005","url":null,"abstract":"<p><p>Axillary dose restriction (ADR) is rarely implemented in breast cancer radiotherapy by radiation oncologists to minimize exposure to organs at risk (OARs), particularly the axilla. This prospective randomized controlled study aims to evaluate the efficacy of ADR in improving plan quality (PQ) and its impact on acute radiation dermatitis (ARD) in breast cancer radiotherapy. The study recruited breast cancer patients who required postoperative radiotherapy but did not have an indication for axillary irradiation. Delineation and dosimetric assessment of the axilla (Axilla Levels I-III and Axillary Cavity) were performed in all cases, with ADR implemented randomly. ADR involved restricting the mean axilla dose to 40-45 Gy during radiotherapy. The outcomes assessed included the ARD grades (both overall and axillary) and dose-volume parameters of PQ including skin V35. The study enrolled 87 patients, who were randomly divided into two groups: Group I (50 patients) received ADR, while Group C (37 patients) did not. ADR was found to be significantly associated with reduced exposure doses to the axilla and ipsilateral lung, specifically in patients with modified radical mastectomy (MRM). Results of other PQ parameters, such as D95, V93, V95, V100, V107 for the planning target volume (PTV), V30, Dmean for the heart, Dmax for the spinal cord, and V5 for the ipsilateral lung, demonstrated potential benefits in alleviating doses to these OARs while maintaining optimized PQ, although these results were not statistically significant. However, no statistically significant correlation between ADR and severe ARD (≥ Grade 2) or skin V35 was established, either in the total patient population or in subgroups. Additionally, a multivariable logistic regression for severe ARD was conducted, with ADR and skin V35 included as predictive factors. Only older age was found to be significantly associated with severe ARD. Implementing ADR in breast cancer radiotherapy not only protects the axilla and ipsilateral lung but also maintains optimized PQ, specifically in MRM patients, though it shows no evidence of alleviating ARD. Adopting ADR may be considered a valuable option in breast cancer radiotherapy.</p>","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2025-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143015066","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":"Does extending the body contour into air enhance surface dose calculation accuracy?","authors":"Joshua N Wancura, Olga M Dona Lemus, Sean M Tanny, Jihyung Yoon, Matthew J Webster, Louis S Constine, Dandan Zheng","doi":"10.1016/j.meddos.2024.12.001","DOIUrl":"https://doi.org/10.1016/j.meddos.2024.12.001","url":null,"abstract":"<p><strong>Purpose: </strong>In radiotherapy treatment planning systems, modelling of superficial dose may be aided by a body contour that is, by default, placed at the outermost air-tissue interface. Here we investigate the accuracy of superficial dose calculated using either the default body contour (DBC) or an extended body contour (EBC) compared to radiochromic film measurements made on a slab phantom and an anthropomorphic phantom.</p><p><strong>Methods: </strong>Depth dose curves in the superficial region of the slab phantom were measured using stacked radiochromic films and irradiated using static beams delivered from varying incident angles. Surface doses on the anthropomorphic phantom were measured using films taped to the outside and irradiated with dynamic beams targeting the skin. No intervening immobilization devices were between the incident beams and films. Measurements were compared with dose calculations performed with Eclipse 15.6 Acuros XB using both the DBC and EBC. The EBC was generated by extending the DBC out into air by 1 cm.</p><p><strong>Results: </strong>Differences between the DBC- and EBC-calculated dose were largest within the region ranging from the surface to a depth of 2 mm. Beyond 2 mm, calculations agreed to within 5%. For the slab phantom, the DBC- and EBC-calculated surface doses for 0-degree incident angle were 26% and 44% respectively, while measured dose was 24 ± 3%. At 60-degrees incident angle, DBC- and EBC-calculated surface doses were 33% and 66% respectively, while the measured dose was 43 ± 3%. For the anthropomorphic phantom, the DBC- and EBC-calculated surface doses were 65% and 99% of the prescription dose respectively, while the measured surface dose was 76 ± 3%.</p><p><strong>Conclusions: </strong>Calculating with the EBC overestimated surface dose, while the DBC underestimated surface dose under conditions of oblique delivery. Overall, the default method of placing the body contour at the air-tissue interface produced a more accurate estimation of surface dose for bare skin.</p>","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142967335","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":"Effectiveness of 4-dimensional maximum intensity projection (4D-MIP) for respiratory motion management with uncertain interobserver delineation.","authors":"Satoki Hinai, Keisuke Usui, Yusuke Obara, Toshiya Maebayashi, Satoshi Ookubo, Atsushi Ichikawa, Yoshihisa Sasaki, Kazuo Ozawa","doi":"10.1016/j.meddos.2024.11.001","DOIUrl":"https://doi.org/10.1016/j.meddos.2024.11.001","url":null,"abstract":"<p><p>This study was conducted to evaluate the use of 4-dimensional (4D) maximum intensity projection (4D-MIP) to compensate for the disadvantages of average intensity projection (AIP), which is used to determine the internal target volume (ITV) in lung tumors. A respiratory motion phantom with a simulated tumor was imaged using 4D computed tomography (4D-CT). AIP and 4D-MIP were generated based on 10 phases of 4D-CT, followed by contouring of the ITV_AIP and ITV_MIP; these were compared with the ITV contoured in 10 phases of 4D-CT (ITV₁₀). Additionally, the profile curves of the ITV_AIP and ITV_MIP were obtained, and the full width at half maximum (FWHM) was measured. There was no significant difference between the ITV₁₀ and ITV_MIP; however, the ITV_AIP demonstrated a lower value. The FWHM values of the ITV_AIP were smaller than those of ITV_MIP owing to decreased CT values in the superior-inferior margin. 4D-MIP may contribute to improving the consistency of the ITV delineation.</p>","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142958060","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":"An assessment of the influence of trade-off optimization in commercial knowledge based planning library creation for tongue cancer patients.","authors":"Subhra S Biswal, Biplab Sarkar, Monika Goyal, Tharmarnadar Ganesh, Tanweer Shahid, Jibak Bhattacharya","doi":"10.1016/j.meddos.2024.10.006","DOIUrl":"https://doi.org/10.1016/j.meddos.2024.10.006","url":null,"abstract":"<p><p>This article aims to compare the dosimetric performance between knowledge-based plan (KBP) libraries with and without trade-off (TO) exploration using multicriterial optimization (MCO) for tongue cancer patients. The trade-off optimized library (KBP_MCO) contains a minimal number of constituent plans, whereas two nontrade-off optimized libraries contain a minimal and a large number of treatment plans, respectively. Three KBP libraries were created: KBP_100 and KBP_20, each comprising of 100 and 20 manually optimized plans, respectively. Additionally, another KBP library (KBP_MCO_20) was created by reoptimizing the constituent plans from KBP_20 using MCO techniques. A total of 70 tongue plans were validated through these libraries. Validation plans were evaluated for PTV and organ at risk (OAR) doses. Greenhouse-Geisser analysis (ANOVA) and the Bonferroni procedure (t-test) were used for statistical evaluation. The mean PTVD95% for KBP_100, KBP_20, and KBP_MCO_20 was 98.4% ± 0.3%, 98.9% ± 0.2%, and 98.7% ± 0.2%, respectively. The statistical significance of PTVD95% for the 3 possible combinations-KBP_100 vs KBP_20, KBP_100 vs KBP_MCO_20, and KBP_20 vs KBP_MCO_20 were statistically significant with p < 0.001. Spinal cord doses for KBP_100, KBP_20, and KBP_MCO_20 were 29.6 ± 1.8 Gy, 31.2 ± 2.5 Gy, and 26.8 ± 1.9 Gy, respectively, with p(KBP_100 vs KBP_20) = 0.14, p(KBP_100 vs KBP_MCO_20) = 0.001, and p(KBP_20 vs KBP_MCO_20) < 0.001. Only the first comparison showed a statistically insignificant variation. A trade-off optimized plan library with a minimal number of patients (20) yields better performance for serial structures (spinal cord and brainstem) compared to large manually optimized KBP libraries. For other organs at risk (OARs) and target dose coverage, although statistical differences were significant in most instances, the differences in physical dose were small and probably will not yield any significant clinical differences.</p>","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142792473","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":"Novel application of an adapted virtual cone technique for the radiosurgical treatment of a 3 mm brain metastasis with a standard multileaf collimator.","authors":"Eric Lobb","doi":"10.1016/j.meddos.2024.10.005","DOIUrl":"https://doi.org/10.1016/j.meddos.2024.10.005","url":null,"abstract":"<p><p>The virtual cone is an innovative MLC-based technique for generating dose distributions comparable to those of physical stereotactic cones. Initially designed for functional radiosurgery applications using a high-definition multileaf collimator (MLC) with 2.5 mm leaf width, this technique has been adapted to a standard 5 mm MLC system for treating small brain metastases. The adapted technique uses preconfigured location-specific control point sequences to produce spherical dose distributions with sharp dose gradients, and facilitates efficient planning through parallelizable template-based workflows. This report highlights the use of the adapted virtual cone technique for treating a 57-year-old patient with a 3 mm brain metastasis from metastatic papillary thyroid carcinoma using a standard multileaf collimator.</p>","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142741167","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 between laterality-specific and general knowledge-based planning models for nonsmall cell lung cancer.","authors":"Julia Seng, Kirk Luca, Justin Roper, Aparna H Kesarwala, Shadab Momin","doi":"10.1016/j.meddos.2024.10.003","DOIUrl":"https://doi.org/10.1016/j.meddos.2024.10.003","url":null,"abstract":"<p><p>To investigate the dosimetric impact of laterality-specific RapidPlan models for nonsmall cell lung cancer. Three RapidPlan models were developed and validated for Right, Left, and General conventional lung radiotherapy. Each model was trained using 50 plans. The right and left models consisted of plans corresponding to their respective laterality. Twenty-five cases were randomly chosen from each laterality-specific model to craft a general model. All models shared identical optimization objectives and the same target and OAR structures. Validation included 13 right-sided and 13 left-sided cases optimized using each RapidPlan model without intervention and normalized such that the prescription dose covered 95% of the target volume. Statistical analysis using a paired sample t-test (p < 0.01) assessed dosimetric endpoints based on RTOG 0617 criteria. For right-sided cases, spinal cord Dmax and D0.03cc were lowest in the left model and highest in the right model (21.08 Gy and 21.22 Gy vs 23.67 Gy and 24.08 Gy). D_max and D_0.03cc esophagus mean dose was also lower in the left model compared to the right model (p < 0.01) for both left and right-sided cases. However, overall plan quality exhibited no substantial difference between general and laterality-specific models. Despite observing small but statistically significant differences, there is no discernible difference in plan quality between laterality-specific and general models, suggesting that a single RapidPlan model is sufficient.</p>","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142734357","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 effects of the leaf positioning error of the halcyon(2.0) dual-layer multileaf collimator (MLC) on the rectal cancer radiotherapy.","authors":"Jiajun Zheng, Yatian Liu, Jianfeng Wu, Li Sun, Dan Zong, Xia He","doi":"10.1016/j.meddos.2024.10.004","DOIUrl":"https://doi.org/10.1016/j.meddos.2024.10.004","url":null,"abstract":"<p><p>To study dosimetric effects of leaf positioning errors (LPEs) of the Halcyon(2.0) dual-layer MLC on the long-course chemoradiotherapy (LCCRT) with 45∼50.4 Gy in 25∼28 fractions for rectal cancer. Nine Halcyon(2.0)-based LCCRT plans of rectal cancer were retrospectively involved. Four types of LPEs were introduced: (1) Uniformly distributed dual-layer random LPEs (Dual-R); (2) Proximal-layer systemic LPEs (P-S); (3) Distal-layer systemic LPEs (D-S); (4) Dual-layer systemic LPEs (Dual-S). The sensitivities of D_98%, D_2% and the Equivalent Uniform Dose (EUD) of PTV to various LPEs were investigated as well as varying ranges of EUDs of OARs. The sensitivities of D_98% and EUD of PTV to Dual-R was -0.65%/mm and -0.38%/mm; the sensitivities of both indices to the P-S and D-S were similar to each other, ranging from 1.92%/mm to 2.87%/mm; both indices were more sensitive to the Dual-S and values were 4.97%/mm and 3.84%/mm respectively. The EUD changes of the bladder, and left and right femoral heads were from -13.23% to 14.82%. Single-side systemic LPEs lower than 0.7 mm are acceptable for Halcyon(2.0)-based LCCRT, while dual-layer systemic LPEs lower than 0.4 mm are acceptable, considering relative changes of 2% for D_98% of PTV as threshold.</p>","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142640084","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":"Evaluation of dose and anatomy variability for nasopharyngeal carcinoma radiotherapy with a new fully integrated CT-linac.","authors":"Fan Zhang, Jing Liu, Mi Zhou, Xutong Li, Lu Yue, Chong Zhao, Zhenyu Qi, Xiaowu Deng, Yinglin Peng, Zhiping Luo","doi":"10.1016/j.meddos.2024.09.005","DOIUrl":"https://doi.org/10.1016/j.meddos.2024.09.005","url":null,"abstract":"<p><p>The goal of this study was to investigate the variability of target volume and parotid gland dose distribution for nasopharyngeal carcinoma (NPC), and to explore the shifting patterns of parotid gland centroid and neck radius during radiotherapy. Twenty patients with NPC were enrolled. The target volume dose difference between planning dose and recalculated dose on weekly CT was analyzed. The recalculated doses on every weekly CT were cumulated to assess the difference between delivered dose and planning dose. The relationship of parotid gland centroid deviation with dose was studied, and the shrinking distances of neck radius were calculated for cervical vertebra 1, 2, 3 levels (C1, C2, C3). The ratio of GTVs and CTVs doses on weekly CTs to the doses on planning CT was all above 0.98; the dose of PTVs on weekly CT tended to decrease compared with planning. RMD was defined as the ratio of the mean dose of the left and right parotid glands (L-PG, R-PG) to the planning mean dose. The fitted relationships of RMD and the deviation of centroid (D) for L-PG and R-PG were: RMD=0.37*D+0.98 (R² = 0.62, p < 0.001) and RMD = 0.33*D+0.97 (R² = 0.72, p < 0.001), respectively. The order of neck radius shrinking distance at different levels was C1>C2=C3. In this study, we quantitatively analyzed the dosimetric variabilities of target volumes, and established linear models of parotid gland dose and its centroid deviation, which provides fractional and full-course dose evaluation during radiotherapy for NPC.</p>","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":" ","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142584780","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, Winter 2024","authors":"","doi":"10.1016/j.meddos.2024.10.002","DOIUrl":"10.1016/j.meddos.2024.10.002","url":null,"abstract":"","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":"49 4","pages":"Page 399"},"PeriodicalIF":1.1,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142551906","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":"Directed Journal Reading (DJR) Program, Winter 2024","authors":"","doi":"10.1016/j.meddos.2024.10.001","DOIUrl":"10.1016/j.meddos.2024.10.001","url":null,"abstract":"","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":"49 4","pages":"Page 398"},"PeriodicalIF":1.1,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142551905","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}