Medical Dosimetry最新文献

{"title":"Comparative dosimetric study of spot-scanning proton therapy versus volumetric-modulated radiation therapy for extrahepatic bile duct cancer","authors":"Toshiyuki Ogata PhD,&nbsp;Norihiro Aibe MD, PhD,&nbsp;Takuya Kimoto MD, PhD,&nbsp;Tadashi Takenaka RTT,&nbsp;Gen Suzuki MD, PhD,&nbsp;Kei Yamada MD, PhD,&nbsp;Hideya Yamazaki MD, PhD","doi":"10.1016/j.meddos.2023.10.004","DOIUrl":"10.1016/j.meddos.2023.10.004","url":null,"abstract":"<div><p><span><span>This study aimed to compare the dose distributions and clarify the dosimetric characteristics of spot-scanning </span>proton therapy<span><span> (SSPT) and photon volumetric modulated arc therapy (VMAT) for extrahepatic </span>bile duct cancer<span> (EBDC). This retrospective study included 10 patients with EBDC treated with real-time image-gated SSPT. Using the simultaneous integrated boost technique, the 2 prescription dose levels for planning target volumes were 72.6 and 44 Gy, delivered in 22 fractions. Plan quality comparisons were conducted by analyzing various parameters, including homogeneity, conformity, dose to organs at risk, and normal tissue complication probability (NTCP) for radiation-induced liver damage (RILD). The target dose distributions using SSPT were almost equivalent to those achieved using photon VMAT. There was a significant reduction in all liver dose parameters, the NTCP value for RILD, and kidney dose (mean, V</span></span></span>_{12 Gy}, and V_{18 Gy}) in SSPT than in photon VMAT. No significant differences were observed in the intestinal doses in the high-dose area. Thus, compared with photon VMAT, SSPT for EBDC significantly reduced radiation doses to the liver and kidneys and has shown potential clinical benefits of reduced radiation-induced toxicity.</p></div>","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":"49 1","pages":"Pages 46-49"},"PeriodicalIF":1.2,"publicationDate":"2023-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71488127","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":"Predictive modeling of dose-volume parameters of carcinoma tongue cases using machine learning models","authors":"Mani Prasannakumar MSc ,&nbsp;Velayudham Ramasubramanian PhD","doi":"10.1016/j.meddos.2023.09.002","DOIUrl":"10.1016/j.meddos.2023.09.002","url":null,"abstract":"<div><p><span><span>The aim of this study is to create a single institution-based machine learning model for a dose prediction generation tool for post-operative carcinoma of the </span>tongue<span> cases prospectively. Intensity-modulated radiotherapy (IMRT) plans for 20 patients with carcinoma of the tongue were generated using the Eclipse </span></span>treatment planning system<span>. A machine learning model was generated using a Python 3.10 computer language in a Jupyter notebook using Anaconda software. The PTVs and OARs doses obtained from the clinical treatment plans were used as a primary dataset. Machine learning models are built with two different datasets (10 and 20) for each selected volume. Volumes from 10 new sets of patients were fed into the software for predicting the corresponding dose values. Through the input given, the plan generated dose values of 10 patients were compared with the predicted outcomes of the 10 and 20 dataset models. The model created using the PTVs volume data predicted the dose values with increased accuracy. By verifying the model prediction with the TPS generated value, both the 10 and 20 dataset models predict all the 10 PTVs data within an error bound of 3% and most of the OARs data within an error bound of 5%. The dosimetric features implemented in the machine learning models reasonably predict both the PTVs dose parameter and OARs constraints and give confidence in decision-making during the clinical planning process.</span></p></div>","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":"49 2","pages":"Pages 109-113"},"PeriodicalIF":1.2,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71428443","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":"A generalized fit index for evaluating treatment plans of multiple target volumes with different prescribed dose: Generalized dose distribution fit index","authors":"Lingling Yan PhD,&nbsp;Yingjie Xu MD,&nbsp;Jianrong Dai PhD","doi":"10.1016/j.meddos.2023.10.005","DOIUrl":"10.1016/j.meddos.2023.10.005","url":null,"abstract":"<div><h3>Background and Purpose</h3><p>The differential fit index (<em>d</em>FI) and cumulative fit index (<em>c</em>FI) were defined in our previous study to evaluate the fit of isodose surfaces to the target volume. They were only applicable to plans for a single target volume. Therefore, this study aimed to generalize these indices for evaluating plans for multiple target volumes and different prescribed doses.</p></div><div><h3>Materials and Methods</h3><p><em>d</em>FI was redefined as the ratio of the integral dose of the volume occupied by an isodose surface to that of the union of all target volumes. <em>c</em>FI was defined as the integral of <em>d</em>FI from a certain dose level of interest to the prescribed dose to be evaluated. To evaluate the performance of the generalized fit index, brain metastasis, head and neck, lung cancer, liver cancer, and cervical cancer cases were selected. For each case, a pair of plans was designed, with one plan having a better fitting dose distribution. The dose fit of these plans was investigated using <em>c</em>FI, the dose gradient index (GI), and the conformity index (CI).</p></div><div><h3>Results</h3><p>In total, 26 pairs of evaluations were performed. The correct evaluation rates for <em>c</em>FI, GI, and CI were 96%, 26.92%, and 92.31%, respectively, illustrating that GI was not valid for evaluating complex plans.</p></div><div><h3>Conclusions</h3><p>The generalized fit index proved effective for evaluating the dose fit of plans for multiple target volumes with different prescribed doses.</p></div>","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":"49 2","pages":"Pages 143-149"},"PeriodicalIF":1.2,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0958394723001012/pdfft?md5=6821b9279324d72b49935e4a7e1c47f1&pid=1-s2.0-S0958394723001012-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71428441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advancing knowledge-based intensity modulated proton planning for adaptive treatment of high-risk prostate cancer","authors":"Casey L. Johnson ,&nbsp;Shaakir Hasan ,&nbsp;Sheng Huang ,&nbsp;Haibo Lin ,&nbsp;Daniel Gorovets ,&nbsp;Andy Shim ,&nbsp;Thomas Apgar ,&nbsp;Francis Yu ,&nbsp;Pingfang Tsai","doi":"10.1016/j.meddos.2023.10.001","DOIUrl":"10.1016/j.meddos.2023.10.001","url":null,"abstract":"<div><p>To assess the performance of a knowledge-based planning (KBP) model for generating intensity-modulated proton therapy (IMPT) treatment plans as part of an adaptive radiotherapy (ART) strategy for patients with high-risk prostate cancer. A knowledge-based planning (KBP) model for proton adaptive treatment plan generation was developed based on thirty patient treatment plans utilizing RapidPlan^TM PT (Varian Medical Systems, Palo Alto, CA). The model was subsequently validated using an additional eleven patient cases. All patients in the study were administered a prescribed dose of 70.2 Gy to the prostate and seminal vesicle (CTV70.2), along with 46.8 Gy to the pelvic lymph nodes (CTV46.8) through simultaneous integrated boost (SIB) technique. To assess the quality of the validation knowledge-based proton plans (KBPPs), target coverage and organ-at-risk (OAR) dose-volume constraints were compared against those of clinically used expert plans using paired <em>t</em>-tests. The KBP model training statistics (<em>R²</em>) (mean ± SD, 0.763 ± 0.167, range, 0.406 to 0.907) and χ² values (1.162 ± 0.0867, 1.039-1.253) indicate acceptable model training quality. Moreover, the average total treatment planning optimization and calculation time for adaptive plan generation is approximately 10 minutes. The CTV70.2 D_98% for the KBPPs (mean ± SD, 69.1 ± 0.08 Gy) and expert plans (69.9 ± 0.04 Gy) shows a significant difference (<em>p</em> &lt; 0.05) but are both within 1.1 Gy of the prescribed dose which is clinically acceptable. While the maximum dose for some organs-at-risk (OARs) such as the bladder and rectum is generally higher in the KBPPs, the doses still fall within clinical constraints. Among all the OARs, most of them received comparable results to the expert plan, except the cauda equina D_max, which shows statistical significance and was lower in the KBPPs than in expert plans (48.5 ± 0.06 Gy <em>vs</em> 49.3 ± 0.05 Gy). The generated KBPPs were clinically comparable to manually crafted plans by expert treatment planners. The adaptive plan generation process was completed within an acceptable timeframe, offering a quick same-day adaptive treatment option. Our study supports the integration of KBP as a crucial component of an ART strategy, including maintaining plan consistency, improving quality, and enhancing efficiency. This advancement in speed and adaptability promises more precise treatment in proton ART.</p></div>","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":"49 1","pages":"Pages 19-24"},"PeriodicalIF":1.2,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0958394723000948/pdfft?md5=211eea6736e728dd9949828a2aacedcc&pid=1-s2.0-S0958394723000948-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71428442","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Two novel stereotactic radiotherapy methods for locally advanced, previously irradiated head and neck cancers patients","authors":"Damodar Pokhrel PhD,&nbsp;Josh Misa BS,&nbsp;Shane McCarthy MS,&nbsp;Eddy S. Yang MD, PhD","doi":"10.1016/j.meddos.2023.09.003","DOIUrl":"10.1016/j.meddos.2023.09.003","url":null,"abstract":"<div><p><span>To determine the feasibility and utility of conebeam CT-guided stereotactic radiotherapy<span><span> for locally recurrent, previously irradiated head and neck cancer<span> (HNC) patients on the Halcyon, a ring delivery system (RDS). This research aims to quantify plan quality, treatment delivery accuracy, and overall efficacy by comparing against novel clinical </span></span>TrueBeam<span><span> HyperArc method. Ten recurrent HNC patients who were treated at our institution on TrueBeam (6MV-FFF) for 30 to 40 Gy in 3 to 5 fractions with noncoplanar HyperArc plans were re-planned on Halcyon (6MV-FFF). These plans were re-planned with the same Acuros-based dose engine. Additionally, we used site-specific full/partial coplanar VMAT arcs. PTV coverage, mean dose to </span>GTV<span>, maximum dose to organs-at-risk (OAR), beam-on time (BOT), and quality assurance (QA) results were investigated and compared. Halcyon provided highly conformal HNC SRT plans with slightly superior mean PTVD99 coverage (96.7% </span></span></span></span><em>vs</em> 95.5%, <em>p</em> = 0.071), and slightly lower mean GTV dose (37.8 Gy <em>vs</em> 38.2 Gy, <em>p</em> = 0.241) when compared to the HyperArc plans. Differences in plan conformality and maximum dose to OARs were statistically insignificant. Due to Halcyon's coplanar geometry, D2cm was significantly higher (<em>p</em> = 0.001) but Halcyon did result in a reduced normal brain dose by 1 Gy on average and up to 5.2 Gy in some cases. Halcyon provided similar patient-specific QA pass rates with a 2%/2mm gamma criteria (98.2% <em>vs</em> 98.5%) and independent in-house Monte Carlo second check results (97.7% <em>vs</em> 98.2%), suggesting identical treatment delivery accuracy. Halcyon plans resulted in slightly longer beam-on time (3.16 vs 2.30 minutes, <em>p</em> = 0.010), however door-to-door patient time is expected to be &lt;10 minutes. Compared to clinical TrueBeam HyperArc, Halcyon SRT plans provided similar plan quality and treatment delivery accuracy with a potentially faster overall treatment using fully automated patient setup and verification. Rapid delivery of recurrent HNC SRT may reduce intrafraction motion errors while also improving patient compliance and comfort. To provide high-quality of HNC SRT similar to HyperArc, we recommend Halcyon users consider commissioning this novel method. This method will be useful for remote and underserved patient cohorts including Halcyon-only clinics as well.</p></div>","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":"49 2","pages":"Pages 114-120"},"PeriodicalIF":1.2,"publicationDate":"2023-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49693440","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":"Hypoglossal nerve delineation in nasopharyngeal carcinoma patients may reduce the radiation dose and damage to the nerve","authors":"Fen Chen MD ,&nbsp;Yee-Min Jen MD, PhD ,&nbsp;Kui He MSc ,&nbsp;Zhao-sheng Yin MD ,&nbsp;Jih-Chin Lee MD ,&nbsp;Wen-Yen Huang MD ,&nbsp;Yong-Hong Tang MD","doi":"10.1016/j.meddos.2023.09.001","DOIUrl":"10.1016/j.meddos.2023.09.001","url":null,"abstract":"<div><p><span><span>This study aims to establish a delineation guideline for the contouring of the hypoglossal nerve by dividing the nerve into different segments, and to test the possibility of a </span>radiation dose reduction<span> to the hypoglossal nerve in NPC patients receiving </span></span>radiotherapy<span><span>. Twenty NPC patients were selected arbitrarily. The hypoglossal nerves were delineated using </span>anatomic landmarks<span> and divided into the cisternal, intracanalicular, carotid, and transverse segments. The tumor coverage by radiation and dose-volume parameters of the nerve with and without various dose constraints to the hypoglossal nerve were compared. The hypoglossal nerve, which is invisible on CT images, can be delineated accurately with the assistance of several anatomic landmarks. Without a dose constraint to the hypoglossal nerve, the carotid space, intracanalicular, and transverse segments had high radiation dose-volumes. The dose-volume to the nerve, however, can be reduced when the nerve was defined and a dose constraint was given. The delineation of the hypoglossal nerve with its different segments is feasible. The carotid space, intracanalicular, and transverse segments received the highest dose, where the nerve damage was most likely located. The dose to the nerve can be reduced to less than 70 Gy using the intensity-modulated radiotherapy technique.</span></span></p></div>","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":"49 2","pages":"Pages 102-108"},"PeriodicalIF":1.2,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49684259","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":"Integrated feathering for craniospinal irradiation improves patient safety and departmental efficiency","authors":"Amy S. Harrison PhD,&nbsp;Angelia Landers PhD,&nbsp;Virginia Nettleton,&nbsp;Katelyn Palermo BS,&nbsp;Yelena Vakhnenko BS,&nbsp;Wenyin Shi MD, PhD","doi":"10.1016/j.meddos.2023.08.008","DOIUrl":"10.1016/j.meddos.2023.08.008","url":null,"abstract":"<div><p><span><span>This paper presents to the dosimetrist audience an integrated feathering technique for craniospinal irradiation which improves </span>dosimetry<span>, physics, physician and therapist efficiencies while increasing </span></span>patient safety<span> and decreasing portal imaging time. This technique has been presented by other authors in physics journals stressing technical and quality assurance aspects, this article is presented to the treatment<span> planners with a focus on the planning process including field design and weighting, efficiency improvements and patient safety.</span></span></p></div>","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":"49 2","pages":"Pages 77-80"},"PeriodicalIF":1.2,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41155661","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 hybrid treatment planning approach for irradiation a pediatric craniospinal axis","authors":"Dr. Christian Ziemann ,&nbsp;Florian Cremers ,&nbsp;Laura Motisi ,&nbsp;Dirk Albers ,&nbsp;Miller MacPherson ,&nbsp;Dirk Rades","doi":"10.1016/j.meddos.2023.08.011","DOIUrl":"10.1016/j.meddos.2023.08.011","url":null,"abstract":"&lt;div&gt;&lt;p&gt;This study presents a new treatment planning approach merging 3D-CRT and VMAT fields into a hybrid treatment plan (HybTP), in order to achieve an optimum dose coverage of the planning target volume (PTV) and protection of OAR. Craniospinal axis irradiation (CSI) treated with 3D conformal radiotherapy (3D-CRT) is associated with high doses to the heart and eye lenses but provides better sparing of lungs and kidneys compared to volumetric modulated arc therapy (VMAT). VMAT treatment spares eye lenses and the heart, but lungs and kidneys are not as effective as 3D-CRT. Thus, a combination of both techniques (HybTP) may be optimal in sparing all these organs at risk (OAR). The results of HybTP are compared with helical tomotherapy (HT), intensity modulated radio therapy (IMRT), VMAT, and 3D-CRT plans. Hybrid, HT, VMAT, IMRT, and 3D-CRT treatment plans for a male child (age 6 years) with medulloblastoma were created and compared. A total dose of 35.2 Gy (PTV) with a dose per fraction of 1.6 Gy was prescribed. The following dose acceptance criteria were defined:&lt;/p&gt;&lt;ul&gt;&lt;li&gt;&lt;span&gt;(1)&lt;/span&gt;&lt;span&gt;&lt;p&gt;Mean PTV dose should be 100% of the prescribed dose, while the maximum dose should not exceed 107%.&lt;/p&gt;&lt;/span&gt;&lt;/li&gt;&lt;li&gt;&lt;span&gt;(2)&lt;/span&gt;&lt;span&gt;&lt;p&gt;At least 98% of the PTV should receive 95% of the prescribed dose.&lt;/p&gt;&lt;/span&gt;&lt;/li&gt;&lt;li&gt;&lt;span&gt;(3)&lt;/span&gt;&lt;span&gt;&lt;p&gt;The cribriform plate should be covered by the 95% isodose line.&lt;/p&gt;&lt;/span&gt;&lt;/li&gt;&lt;li&gt;&lt;span&gt;(4)&lt;/span&gt;&lt;span&gt;&lt;p&gt;The acceptance criteria for the OARs were: lenses &lt;em&gt;D&lt;sub&gt;max&lt;/sub&gt;&lt;/em&gt;&lt;10 Gy, lungs &lt;em&gt;D&lt;sub&gt;mean&lt;/sub&gt;&lt;/em&gt;&lt;7 Gy, kidneys &lt;em&gt;D&lt;sub&gt;mean&lt;/sub&gt;&lt;/em&gt;&lt;15 Gy, heart &lt;em&gt;D&lt;sub&gt;mean&lt;/sub&gt;&lt;/em&gt;&lt;26 Gy, and heart &lt;em&gt;V&lt;sub&gt;25&lt;/sub&gt;&lt;/em&gt;&lt;10%.&lt;/p&gt;&lt;/span&gt;&lt;/li&gt;&lt;/ul&gt;&lt;p&gt;The plans were compared regarding dose homogeneity index (HI) and conformity index (CI), PTV coverage, (particularly at cribriform plate) and doses at OARs. Best conformity was achieved with HT (CI = 0.98) followed by VMAT (CI = 0.96), IMRT (CI = 0.91), HybTP (CI = 0.86), and 3D-CRT (CI = 0.83). The homogeneity index varied marginally. For both HT and IMRT the HI was 0.07, and for 3D-CRT, VMAT and HybTP the HI was between 0.13 and 0.15. The cribriform plate was sufficiently covered by HybTP, VMAT, and 3D-CRT. The dose acceptance criteria for OARs were met by HT and HybTP. VMAT did not meet the criteria for lung (&lt;em&gt;D&lt;sub&gt;mean&lt;/sub&gt;&lt;/em&gt; = right 10.4 Gy/left 10.2 Gy), 3D-CRT did not meet the criteria for eye lenses (&lt;em&gt;D&lt;sub&gt;max&lt;/sub&gt;&lt;/em&gt; = right 32.3 Gy/left 33.1), and heart (&lt;em&gt;V&lt;sub&gt;25&lt;/sub&gt;&lt;/em&gt;≈44%) and IMRT did not meet the criteria for lung (&lt;em&gt;D&lt;sub&gt;mean&lt;/sub&gt;&lt;/em&gt; = right 11.1 Gy/left 11.2 Gy) and eye lenses (&lt;em&gt;D&lt;sub&gt;max&lt;/sub&gt;&lt;/em&gt; = right 12.2 Gy/left 13.1). HybTP meets all defined acceptance criteria and has proved to be a reasonable alternative for CSI. With HybTP that combines VMAT at the brain and heart with 3D-CRT posterior spinal fields (to spare lungs and kidneys), both appropriate coverage of the PTV","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":"49 2","pages":"Pages 93-101"},"PeriodicalIF":1.2,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0958394723000766/pdfft?md5=037d95a42c17a31f394e7344d19f5276&pid=1-s2.0-S0958394723000766-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41160280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Technical Report: Efficient constancy evaluation of the Eclipse treatment planning system's photon and electron dose calculation algorithms aided by the third-party ClearCheck software","authors":"Eric Lobb MS","doi":"10.1016/j.meddos.2023.08.009","DOIUrl":"10.1016/j.meddos.2023.08.009","url":null,"abstract":"<div><p>Our institutional approach to performing periodic constancy checks on dose calculations for the Varian Eclipse treatment planning system<span> is described, including details of how the Radformation ClearCheck software is leveraged for highly efficient results analysis. Photon- and electron-specific synthetic phantoms are created which allow all modality-specific fields to be spatially separated and calculated in a single plan, with field-specific structures encompassing individual irradiated volumes facilitating field-specific dose distribution<span> evaluations. Plan comparison templates in ClearCheck allow for the near-instantaneous evaluation of 116 and 165 individual calculation metrics for photon and electron fields, respectively. The methodology is further applied to the Radformation ClearCalc finite-size pencil beam and electron algorithms for secondary algorithm validation. The total time required for constancy evaluations of 6 primary algorithms and 4 secondary algorithms is less than one hour, with much of that time used for passive dose calculation.</span></span></p></div>","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":"49 2","pages":"Pages 81-84"},"PeriodicalIF":1.2,"publicationDate":"2023-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41179072","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 RapidArc and HyperArc in hippocampal-sparing whole-brain radiotherapy with a simultaneous integrated boost","authors":"Jeongho Kim PhD ,&nbsp;Tae Gyu Kim MD ,&nbsp;Byungdo Park PhD ,&nbsp;Hyunjung Kim MD ,&nbsp;Yun Gyu Song MD ,&nbsp;Hyoun Wook Lee MD ,&nbsp;Young Zoon Kim MD ,&nbsp;Jun Ho Ji MD ,&nbsp;Seok-Hyun Kim MD ,&nbsp;Sung Min Kim MD ,&nbsp;Jun Ho Lee MD ,&nbsp;Haeyoung Kim MD","doi":"10.1016/j.meddos.2023.08.007","DOIUrl":"10.1016/j.meddos.2023.08.007","url":null,"abstract":"<div><p><span>The HyperArc technique is known for generating high-quality radiosurgical treatment plans for intracranial lesions or hippocampal-sparing whole-brain </span>radiotherapy<span><span> (WBRT). However, there is no reported feasibility of using the HyperArc technique in hippocampal-sparing WBRT with a simultaneous integrated boost (SIB). This study aimed to compare dosimetric parameters of 2 commercially-available volumetric-modulated arc radiotherapy techniques, HyperArc and </span>RapidArc<span>, when using hippocampal-sparing WBRT with a SIB to treat brain metastases.</span></span></p><p><span>Treatment plans using HyperArc and RapidArc techniques were generated retrospectively for 19 previously treated patients (1 to 3 brain metastases). The planning target volumes for the whole brain (excluding the hippocampal avoidance region; PTV</span>_WB<span>) and metastases (PTV</span>_met) were prescribed 25 and 45 Gy, respectively, in 10 fractions. Each plan included homogeneous and inhomogeneous delivery to the PTV_met. Dosimetric parameters for the target (conformity index [CI], homogeneity index [HI], target coverage [D_95%]), and nontarget organs at risk were compared for the HyperArc and RapidArc plans.</p><p>For homogeneous delivery, dosimetric parameters, including mean CI, HI, and target coverage in PTV_WB and PTV_met, were superior for HyperArc than RapidArc plans (all <em>p</em> &lt; 0.01). The PTV_WB and PTV_met target coverage for HyperArc plans was significantly greater than for RapidArc plans (96.17% <em>vs</em> 93.38%, <em>p</em> &lt; 0.01; 94.02% <em>vs</em> 92.21%, <em>p</em> &lt; 0.01, respectively). HyperArc plans had significantly lower mean hippocampal D_max and D_min values than RapidArc plans (D_max: 15.53 Gy <em>vs</em>, 16.71 Gy, <em>p</em> &lt; 0.01; D_min: 8.33 Gy <em>vs</em> 8.93 Gy, <em>p</em> &lt; 0.01, respectively). Similarly, inhomogeneous delivery of hyperArc produced a superior target and lower hippocampal dosimetric parameters than RapidArc, except for the HI of PTV_met (all <em>p</em> &lt; 0.01).</p><p>HyperArc generated superior conformity and target coverage with lower hippocampal doses than RapidArc. HyperArc could be an attractive technique for hippocampal-sparing WBRT with an SIB.</p></div>","PeriodicalId":49837,"journal":{"name":"Medical Dosimetry","volume":"49 2","pages":"Pages 69-76"},"PeriodicalIF":1.2,"publicationDate":"2023-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10634587","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}