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.

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.

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.

Dose volume histogram analysis for organs at risk when using 6 external beam techniques for radical prostatic irradiation

2000 ◽  
Vol 2 (1) ◽  
pp. 17-25 ◽  
Author(s):  
T. Haycocks ◽  
J. Mui ◽  
H. Alasti ◽  
C. Catton
Keyword(s):  
At Risk ◽  
Organs At Risk ◽  
Area Under The Curve ◽  
Target Volume ◽  
Dose Volume Histograms ◽  
Treatment Techniques ◽  
Dose Volume ◽  
Femoral Heads ◽  
Curve Method ◽  
Set Up

Ten patients with prostate cancer were each planned with 3 conventional and 3 conformal isocentric treatment techniques to compare the relative radiation doses to the bladder and rectal walls, and femoral head using dose volume histograms (DVH). The DVH were calculated for each organ and each technique, and the plans were ranked using the area under the curve method and also by the relative radiation dose given to specific normal tissue volumes.The results show that for the planning target volume chosen, the 4 field non-coplanar technique delivers the least dose to the bladder, the 6 field coplanar technique delivers the least dose to the rectum and the 3 field oblique technique delivers the least dose to the femoral heads. The 4-field technique with no shielding contributes the most dose to the bladder and rectum and the 6 field coplanar technique contributes the most dose to the femoral heads.No technique was shown to be optimal for all the organs at risk, but both the 6 field and 4 field non-coplanar field arrangements were shown to be superior techniques for minimising both the bladder and rectal dosage. The choice of technique will therefore depend on other factors such as the total prescribed dose, the ease of set-up and the ease of verification of isocentre reproducibility.

Evaluation of plan optimisers in prostate VMAT using the dose distribution index

2019 ◽  
Vol 18 (4) ◽  
pp. 323-328 ◽  
Author(s):  
James C. L. Chow ◽  
Runqing Jiang ◽  
Lu Xu
Keyword(s):  
At Risk ◽  
Dose Distribution ◽  
Organs At Risk ◽  
Volumetric Modulated Arc Therapy ◽  
Target Volume ◽  
Weighting Factor ◽  
Target Coverage ◽  
Dose Volume Histograms ◽  
Dose Volume ◽  
Distribution Index

AbstractPurpose:Dose distribution index (DDI) is a treatment planning evaluation parameter, reflecting dosimetric information of target coverage that can help to spare organs at risk (OARs) and remaining volume at risk (RVR). The index has been used to evaluate and compare prostate volumetric modulated arc therapy (VMAT) plans using two different plan optimisers, namely photon optimisation (PO) and its predecessor, progressive resolution optimisation (PRO).Materials and methods:Twenty prostate VMAT treatment plans were created using the PO and PRO in this retrospective study. The 6 MV photon beams and a dose prescription of 78 Gy/39 fractions were used in plans with the same dose–volume criteria for plan optimisation. Dose–volume histograms (DVHs) of the planning target volume (PTV), as well as of OARs such as the rectum, bladder, left and right femur were determined in each plan. DDIs were calculated and compared for plans created by the PO and PRO based on DVHs of the PTV and all OARs.Results:The mean DDI values were 0·784 and 0·810 for prostate VMAT plans created by the PO and PRO, respectively. It was found that the DDI of the PRO plan was about 3·3% larger than the PO plan, which means that the dose distribution of the target coverage and sparing of OARs in the PRO plan was slightly better. Changing the weighting factors in different OARs would vary the DDI value by ∼7%. However, for plan comparison based on the same set of dose–volume criteria, the effect of weighting factor can be neglected because they were the same in the PO and PRO.Conclusions:Based on the very similar DDI values calculated from the PO and PRO plans, with the DDI value in the PRO plan slightly larger than that of the PO, it may be concluded that the PRO can create a prostate VMAT plan with slightly better dose distribution regarding the target coverage and sparing of OARs. Moreover, we found that the DDI is a simple and comprehensive dose–volume parameter for plan evaluation considering the target, OARs and RVR.

Monte Carlo (MC)-based volumetric modulated arc therapy (VMAT) in locally advanced esophageal cancer with potential for dose escalation.

2014 ◽  
Vol 32 (3_suppl) ◽  
pp. 77-77
Author(s):  
Shaakir Hasan ◽  
Anil Sethi ◽  
Jennifer Breunig ◽  
Gabriel Axelrud ◽  
William Small ◽  
...  
Keyword(s):  
Dose Escalation ◽  
Organs At Risk ◽  
Locally Advanced ◽  
Volumetric Modulated Arc Therapy ◽  
Intensity Modulated Radiotherapy ◽  
Conformal Radiotherapy ◽  
Target Volume ◽  
Target Dose ◽  
Treatment Techniques ◽  
Prescription Dose

77 Background: Previous attempts at dose escalation in esophagus radiotherapy (RT), mostly based on older planning techniques, have not shown improved outcomes. We aimed to investigate the importance of newer, sophisticated dose algorithms and treatment techniques in escalating target dose and reducing dose to organs at risk (OAR). Methods: Treatment plans for 10 patients were retrospectively evaluated using 3D conformal radiotherapy (3DCRT), MC based intensity modulated radiotherapy (IMRT), and VMAT. Prescription dose was 45 Gy to the planning target volume (PTV) in 25 fractions followed by a 5.4 Gy boost in 3 fractions. PTV (mean±s.d. = 681±236 cc) were planned with BrainLab iPlan 4.1 software as IMRT and VMAT. Dose distributions were calculated with both pencil beam (PB) and MC algorithms. Each PTV was normalized to receive at least 95% of 50.4 Gy or 60 Gy dose. OARs were evaluated as per RTOG1010 dose guidelines. Paired t-tests were used for statistical analysis. Results: IMRT vs. 3DCRT PTV 50.4 Gy: IMRT plans decreased heart and lung average Dmean by 4.7 Gy (p = 0.053) and 1.9 Gy (p = 0.001) respectively when compared to 3DCRT. In addition, average values of lung V5, V10, and V30 also reduced by 7.1%, 5.5%, and 3.6% respectively (p < 0.05). There was a 12.1% decrease in heart V40 (p=0.053) and 3.7% reduction in liver V30 (p=0.08). PTV 60Gy: IMRT plans at 60 Gy led to lower OAR doses compared to 3DCRT at 50.4 Gy. MC based IMRT results did not significantly differ from PB, with the exception of lung V5 which was 4.4% higher (p <0.001). VMAT vs. IMRT PTV 50.4 Gy: VMAT based planning, compared to IMRT, lowered V20 (3.4%, p=0.029), V30 (1.6%, p = 0.013), and spinal cord Dmax (5.4 Gy, p = 0.001). However, lung Dmean, V5, and V10 increased by 1.2 Gy, 11.7%, 16.7% respectively (p < 0.001). PTV 60 Gy: With VMAT planning, all OAR dose parameters were within the RTOG 1010 limits, although lung V5 and V10 exceeded acceptable limits by 1.6% and 2.6% respectively. Conclusions: Compared to 3DCRT, target dose escalation with IMRT and VMAT is possible with improved OAR dose sparing, as evaluated with MC algorithms. Increased dose values for V5 and V10 as seen in MC based VMAT plans call for reassessment of RTOG 1010 guidelines.

scholarly journals Conformal Radiotherapy Facilitates the Delivery of Concurrent Chemotherapy and Radiotherapy: A Case of Primitive Neuroectodermal Tumour of the Chest Wall

Sarcoma ◽  
2000 ◽  
Vol 4 (3) ◽  
pp. 129-133 ◽  
Author(s):  
C. E. Coles ◽  
N. Twyman ◽  
H. M. Earl ◽  
N. G. Burnet
Keyword(s):  
Chest Wall ◽  
Organs At Risk ◽  
Conformal Radiotherapy ◽  
Target Volume ◽  
Concurrent Chemotherapy ◽  
Radiotherapy Planning ◽  
Primitive Neuroectodermal Tumour ◽  
Normal Tissues ◽  
Neuroectodermal Tumour ◽  
Red Marrow

We illustrate the principle of conformal radiotherapy by discussing the case of a patient with a primitive neuroectodermal tumour of the chest wall. Recent advances in radiotherapy planning enable precise localization of the planning target volume (PTV) and normal organs at risk of irradiation. Customized blocks are subsequently designed to produce a treatment field that ‘conforms’ to the PTV. The use of conformal radiotherapy (CRT) in this case facilitated the delivery of concurrent chemotherapy and radiotherapy by significantly reducing the volume of red marrow irradiated.The lack of acute and late toxicities was attributed to optimal exclusion of normal tissues from the treatment field, made possible by CRT.

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.

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