Dosimetry Analysis of Three Kinds of Radiation Technique for Postoperative Gastric Cancer

2013 ◽  
Vol 641-642 ◽  
pp. 725-731
Author(s):  
Hua Tang ◽  
Ju Dong Luo ◽  
Xu Jing Lu ◽  
Ling Chen ◽  
Yan Ma ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Spinal Cord ◽  
Treatment Planning ◽  
Statistical Difference ◽  
Intensity Modulated Radiotherapy ◽  
Conformal Radiotherapy ◽  
Target Volume ◽  
Dose Volume Histograms ◽  
Dose Volume ◽  
Better Than

Objective: To compare dose-volume histograms (DVHs) and the dose distribution of three-dimensional conformal radiotherapy(3DCRT),7 fields radiotherapy(7FRT) and intensity-modulated radiotherapy (IMRT) of treatment planning in gastric cancer. Methods: We selected 5 patients with gastric cancer, they were pathologically confirmed stage T3,T4 or N+ gastric cancer. All patients underwent radical gastrectomy. A dosimetry study was carried out on these five patients. For each patient, three kinds of treatment planning were designed with a prescribed dose of 45Gy to 95％of PTV.Many kinds of parameters of these plans in each patient were compared: isodose distributions line、dose-volume histogram(DVH)、V95%、V110%、CI、HI、EI of target volume and the dose of related critical organs. Results: IMRT was superior to 3DCRT and 7F-RT in dose uniformity（p＜0.05）, there was no statistical difference between 3DCRT and 7FRT in CI（p>0.05）.IMRT had better dose conformity than 3DCRT and 7FRT（p＜0.05）, and 3DCRT was better than 7FRT in CI（p＜0.05）.IMRT showed better EI than 3DCRT and 7FRT（p＜0.05）,there was no statistical difference between 3DCRT and 7FRT in EI（p>0.05）.IMRT had advantage at sparing liver compared with 3DCRT and 7FRT（p＜0.05）,7FRT showed better D1/3 of liver than 3DCRT（p＜0.05）,but there was no statistical difference between 3DCRT and 7FRT in Dmean of liver（p>0.05）.IMRT expressed better Dmax of spinal cord than 3DCRT and 7F-RT（p＜0.05）, and 7FRT was better than IMRT in Dmax of spinal cord（p＜0.05）.But the dose received by the both kidneys were not significantly different. Conclusion: IMRT is superior to 3DCRT and 7FRT,and 3DCRT plans showed better CI and Dmax of spinal cord composed to 7FRT,and 7FRT was superior to 3DCRT in D1/3 of liver. IMRT for gastric cancer had physics advantage for clinical application.

A dosimetric comparison of craniospinal irradiation using TomoDirect radiotherapy, TomoHelical radiotherapy and 3D conventional radiotherapy

2017 ◽  
Vol 16 (4) ◽  
pp. 391-402
Author(s):  
Shirley W. S. Tsang ◽  
Mark Collins ◽  
Jacky T. L. Wong ◽  
George Chiu
Keyword(s):  
Organs At Risk ◽  
Intensity Modulated Radiotherapy ◽  
Conformal Radiotherapy ◽  
Target Volume ◽  
Craniospinal Irradiation ◽  
Conventional Radiotherapy ◽  
Biological Damage ◽  
Dose Volume Histograms ◽  
Normal Tissues ◽  
Dose Volume

AbstractAimThe purpose of this study was to dosimetrically compare TomoDirect, TomoHelical and linear accelerator-based 3D-conformal radiotherapy (Linac-3DCRT) for craniospinal irradiation (CSI) in the treatment of medulloblastoma.MethodsFive CSI patients were replanned with Linac-3DCRT, TomoHelical, TomoDirect-3DCRT and TomoDirect-intensity-modulated radiotherapy (IMRT). Dose of 36 Gy in 20 fractions was prescribed to the planning target volume (PTV). Homogeneity index (HI), non-target integral dose (NTID), dose–volume histograms, organs-at-risk (OARs)Dmax,Dmeanand treatment times were compared.ResultsTomoHelical achieved the best PTV homogeneity compared with Linac-3DCRT, TomoDirect-3DCRT and TomoDirect-IMRT (HI of 3·6 versus 20·9, 8·7 and 9·4%, respectively). TomoDirect-IMRT achieved the lowest NTID compared with TomoDirect-3DCRT, TomoHelical and Linac-3DCRT (141 J versus 151 J, 181 J and 250 J), indicating least biological damage to normal tissues. TomoHelical plans achieved the lowestDmaxin all organs except the breasts, and lowestDmeanfor most OARs, except in laterally situated OARs, where TomoDirect triumphed. Beam-on time was longest for TomoHelical, followed by TomoDirect and Linac-3DCRT.FindingsTomoDirect has the potential to lower NTID and shorten treatment times compared with TomoHelical. It reduces PTV inhomogeneity and better spares OARs compared with Linac-3DCRT. Therefore, TomoDirect may be a CSI treatment alternative to TomoHelical and in place of Linac-3DCRT.

Challenges and Differences in External Radiation Therapy for Retinoblastoma: From Standard Techniques to New Developments

2015 ◽  
Vol 103 (5) ◽  
pp. 438-442
Author(s):  
Ayşe Hiçsönmez ◽  
Yıldız Güney ◽  
Ayşen Dizman ◽  
Bahar Dirican ◽  
Yakup Arslan ◽  
...  
Keyword(s):  
Bone Growth ◽  
External Beam Radiotherapy ◽  
Intensity Modulated Radiotherapy ◽  
Target Volume ◽  
Dose Volume Histograms ◽  
Normal Tissues ◽  
Dose Volume ◽  
Significant Difference ◽  
Treatment Plans ◽  
External Radiation Therapy

Aims The purpose of this study is to calculate the treatment plans and to compare the dose distributions and dose-volume histograms (DVH) for 6 external radiotherapy techniques for the treatment of retinoblastoma as well as intensity-modulated radiotherapy (IMRT) and fractionated stereotactic radiotherapy (Cyberknife). Methods Treatment plans were developed using 6 techniques, including an en face electron technique (ET), an anterior and lateral wedge photon technique (LFT), a 3D conformal (6 fields) technique (CRT), an inverse plan IMRT, tomotherapy, and conventional focal stereotactic external beam radiotherapy with Cyberknife (SBRT). Dose volume analyses were carried out for each technique. Results All techniques except electron provided similar target coverage. When comparing conformal plan with IMRT and SBRT, there was no significant difference in planning target volume dose distribution. The mean volume of ipsilateral bony orbit received more than 20 Gy, a suggested threshold for bone growth inhibition. The V20 Gy was 73% for the ET, 57% for the LFT, 87% for the CRT, 65% for the IMRT, 66% for the tomotherapy, and 2.7% for the SBRT. Conclusions This work supports the potential use of IMRT and SBRT to spare normal tissues in these patients.

scholarly journals Adaptive radiotherapy for head and neck cancer reduces the requirement for rescans during treatment due to spinal cord dose

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Louise Belshaw ◽  
Christina E. Agnew ◽  
Denise M. Irvine ◽  
Keith P. Rooney ◽  
Conor K. McGarry
Keyword(s):  
Spinal Cord ◽  
Head And Neck ◽  
Treatment Plan ◽  
Volumetric Modulated Arc Therapy ◽  
Target Volume ◽  
Adaptive Radiotherapy ◽  
Dose Increase ◽  
Volume Changes ◽  
Dose Volume Histograms ◽  
Dose Volume

Abstract Background Patients treated with radiotherapy for head and neck (H&N) cancer often experience anatomical changes. The potential compromises to Planning Target Volume (PTV) coverage or Organ at Risk (OAR) sparing has prompted the use of adaptive radiotherapy (ART) for these patients. However, implementation of ART is time and resource intensive. This study seeks to define a clinical trigger for H&N re-plans based on spinal cord safety using kV Cone-Beam Computed Tomography (CBCT) verification imaging, in order to best balance clinical benefit with additional workload. Methods Thirty-one H&N patients treated with Volumetric Modulated Arc Therapy (VMAT) who had a rescan CT (rCT) during treatment were included in this study. Contour volume changes between the planning CT (pCT) and rCT were determined. The original treatment plan was calculated on the pCT, CBCT prior to the rCT, pCT deformed to the anatomy of the CBCT (dCT), and rCT (considered the gold standard). The dose to 0.1 cc (D0.1cc) spinal cord was evaluated from the Dose Volume Histograms (DVHs). Results The median dose increase to D0.1cc between the pCT and rCT was 0.7 Gy (inter-quartile range 0.2–1.9 Gy, p < 0.05). No correlation was found between contour volume changes and the spinal cord dose increase. Three patients exhibited an increase of 7.0–7.2 Gy to D0.1cc, resulting in a re-plan; these patients were correctly identified using calculations on the CBCT/dCT. Conclusions An adaptive re-plan can be triggered using spinal cord doses calculated on the CBCT/dCT. Implementing this trigger can reduce patient appointments and radiation dose by eliminating up to 90% of additional un-necessary CT scans, reducing the workload for radiographers, physicists, dosimetrists, and clinicians.

Volumetric modulated arc therapy versus 3D conformal radiotherapy for selected childhood neoplasms

2014 ◽  
Vol 14 (1) ◽  
pp. 35-42 ◽  
Author(s):  
Marzanna Chojnacka ◽  
Anna Zygmuntowicz-Piętka ◽  
Anna Semaniak ◽  
Katarzyna Pędziwiatr ◽  
Ryszard Dąbrowski ◽  
...  
Keyword(s):  
At Risk ◽  
Organs At Risk ◽  
Volumetric Modulated Arc Therapy ◽  
Conformal Radiotherapy ◽  
Target Volume ◽  
High Dose ◽  
Dose Volume Histograms ◽  
Dose Volume ◽  
Arc Therapy ◽  
Childhood Neoplasms

AbstractAimThe comparative study of the plan quality between volumetric modulated arc therapy (VMAT) and 3D conformal therapy (3DCRT) for the treatment of selected representative childhood neoplasms was performed.Materials and methodsDuring the year 2013, 44 children with neoplasms were irradiated using VMAT. The 3DCRT plans were created retrospectively and compared with the VMAT plans for four tumour locations. The conformity parameters, dose volume histograms for target volume and organs at risk, number of monitor units and time used to deliver the single fraction were evaluated and compared for each plan. Additionally, for patients with brain tumour the comparison of different arcs configuration was made.ResultsVMAT modality presented the superiority over older conformal methods with regard to the improvement in the dose conformity and normal tissue sparing. The noncoplanar arcs arrangement was beneficial in the decrease of high-dose volume and the protection of the organs at risk located oppositely to the target volume.FindingsVMAT could be preferred technique for treating childhood neoplasms, especially when the complex-shaped target volume is localised close to the critical structures. The noncoplanar arcs arrangement could be the method of choice in the reirradiated patients and in these with laterally located brain tumours.

Dosimetric study on the use of Eclipse beam angle optimiser for conformal planning

2021 ◽  
pp. 1-4
Author(s):  
Yousif A. M. Yousif ◽  
Ali Judge ◽  
Jackson Zifodya
Keyword(s):  
Radiation Therapy Oncology Group ◽  
Three Dimensional ◽  
Conformal Radiotherapy ◽  
Target Volume ◽  
Radiotherapy Planning ◽  
Beam Angle ◽  
Dose Volume Histograms ◽  
Dose Volume ◽  
Collimator Angle ◽  
Three Dimensional Conformal Radiotherapy

Abstract Aim: The aim of this study was to evaluate the use of Eclipse’s beam angle optimiser (BAO) for three-dimensional conformal radiotherapy planning. Materials and methods: Eleven 3D conformal lung plans, with varied tumour volumes, were retrospectively studied. For each clinical plan, a BAO plan was produced and then optimised by an experienced planner. Plan quality was assessed using International Commission on Radiation Units and Measurements (ICRU)-83 and  Radiation Therapy Oncology Group (RTOG) recommended dose reporting metrics for dose volume prescribing and reporting. Results: Differences in dose volume histograms for both methods showed no clinical significance. Planning target volume Dmax for both plans was comparable and within ICRU guidelines. Reported spinal cord Dmax and the doses to 33% and 67% volume of the heart were within the RTOG recommended limits. Mean lung V20 values for BAO and non-BAO plans were 20 and 16%, respectively. The average monitor units for the BAO plans were about 11% lower. The conformity and homogeneity indices were within the acceptable range for both cases. On average, it took 23 minutes to plan using the BAO compared to 68 minutes for the non-BAO plans. Conclusion: Eclipse BAO shows the potential to produce good quality conformal plans and reduce planning time. This process could be further refined with multi-leaf collimator and optimal collimator angle options.

Dosimetric comparison between the prostate intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) plans using the planning target volume (PTV) dose–volume factor

2016 ◽  
Vol 15 (3) ◽  
pp. 263-268 ◽  
Author(s):  
James C. L. Chow ◽  
Runqing Jiang ◽  
Alexander Kiciak ◽  
Daniel Markel
Keyword(s):  
Planning Target Volume ◽  
Volumetric Modulated Arc Therapy ◽  
Intensity Modulated Radiotherapy ◽  
Target Volume ◽  
Conformity Index ◽  
Volume Factor ◽  
Dose Volume Histograms ◽  
Intensity Modulated ◽  
Dose Volume ◽  
Arc Therapy

AbstractBackgroundWe demonstrated that our proposed planning target volume (PTV) dose–volume factor (PDVF) can be used to evaluate the PTV dose coverage between the intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) plans based on 90 prostate patients.PurposePDVF were determined from the prostate IMRT and VMAT plans to compare their variation of PTV dose coverage. Comparisons of the PDVF with other plan evaluation parameters such as D5%, D95%, D99%, Dmean, conformity index (CI), homogeneity index (HI), gradient index (GI) and prostate tumour control probability (TCP) were carried out.Methods and materialsProstate IMRT and VMAT plans using the 6 MV photon beams were created from 40 and 50 patients, respectively. Dosimetric indices (CI, HI and GI), dose–volume points (D5%, D95%, D99% and Dmean) and prostate TCP were calculated according to the PTV dose–volume histograms (DVHs) of the plans. All PTV DVH curves were fitted using the Gaussian error function (GEF) model. The PDVF were calculated based on the GEF parameters.ResultsFrom the PTV DVHs of the prostate IMRT and VMAT plans, the average D99% of the PTV for IMRT and VMAT were 74·1 and 74·5 Gy, respectively. The average prostate TCP were 0·956 and 0·958 for the IMRT and VMAT plans, respectively. The average PDVF of the IMRT and VMAT plans were 0·970 and 0·983, respectively. Although both the IMRT and VMAT plans showed very similar prostate TCP, the dosimetric and radiobiological results of the VMAT technique were slightly better than IMRT.ConclusionThe calculated PDVF for the prostate IMRT and VMAT plans agreed well with other dosimetric and radiobiological parameters in this study. PDVF was verified as an alternative of evaluation parameter in the quality assurance of prostate treatment planning.

A comparison of proton and photon radiotherapy in reducing cardiac exposure for patients receiving radiation therapy for distal and esophagogastric junction cancer.

2014 ◽  
Vol 32 (3_suppl) ◽  
pp. 167-167
Author(s):  
Ted Chen-Tai Ling ◽  
Jerry Monroe Slater ◽  
Rachel Mifflin ◽  
Prashanth Nookala ◽  
Roger Grove ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Esophagogastric Junction ◽  
Intensity Modulated Radiotherapy ◽  
Target Volume ◽  
Dose Distributions ◽  
Dose Volume Histograms ◽  
Dose Volume ◽  
Partial Volumes ◽  
Treatment Plans ◽  
Adequate Coverage

167 Background: Recent studies indicate that radiation exposure to heart may have a greater impact on perioperative cardiac morbidities than do other clinical factors. The purpose of this study is to investigate dose distributions of proton and photon treatment plans in patients (pts) with distal and esophagogastric junction (GEJ) carcinoma, focusing specifically on dose reduction to cardiac structures. Methods: Ten pts between 2010 and 2013 were included in this study. Three separate plans were generated for each patient: 3D proton plan, 3D photon plan, and Intensity modulated radiotherapy (IMRT) photon plan. The clinical target volume (CTV) consisted of the pre-operative extent of tumor plus a 10mm manual expansion in all directions. The planning target volume (PTV) was generated by a further expansion on the CTV ranging from 10-15mm. A dose of 50.4Gy given in 28 fractions was delivered to the PTV. All plans were optimized to allow 90% isodose coverage of at least 95% of the PTV. Dose-volume histograms were calculated and analyzed in order to compare plans between the three modalities. ANOVA and two-tailed paired t-tests were performed for all data parameters. Results: The 3D proton plans showed decreased dose to partial volumes of the entire heart, arteries, valves, atria, and ventricles in comparison to both the IMRT and 3D photon plans (see Table). The IMRT plans showed decreased dose delivered to the LAD artery, pericardium, and atria in comparison to the 3D photon plans (see Table). Conclusions: For pts receiving radiation therapy for distal esophageal and GEJ cancer, proton plans are technically feasible with adequate coverage while resulting in lower dose to cardiac structures. This may result in decreased cardiac toxicity and less complications in a multimodality setting. [Table: see text]

Sign in / Sign up

Export Citation Format

Share Document