scholarly journals Dosimetric and radiobiological comparison of treatment plan between CyberKnife and EDGE in stereotactic body radiotherapy for pancreatic cancer

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhi-tao Dai ◽  
Li Ma ◽  
Ting-ting Cao ◽  
Lian Zhu ◽  
Man Zhao ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Spinal Cord ◽  
Stereotactic Body Radiotherapy ◽  
Dose Distribution ◽  
Normal Tissue ◽  
Organs At Risk ◽  
Treatment Plan ◽  
Locally Advanced ◽  
Conformity Index ◽  
Homogeneous Dose

AbstractTo perform a comparison of the different stereotactic body radiotherapy (SBRT) plans between the Varian EDGE and CyberKnife (CK) systems for locally advanced unresectable pancreatic cancer. Fifteen patients with pancreatic cancer were selected in this study. The median planning target volume (PTV) was 28.688 cm3 (5.736–49.246 cm3). The SBRT plans for the EDGE and CK were generated in the Eclipse and Multiplan systems respectively with the same contouring and dose constrains for PTV and organs at risk (OARs). Dose distributions in PTV were evaluated in terms of coverage, conformity index (CI), new conformity index (nCI), homogeneity index (HI), and gradient index (GI). OARs, including spinal cord, bowel, stomach, duodenum and kidneys were statistically evaluated by different dose-volume metrics and equivalent uniform dose (EUD). The volume covered by the different isodose lines (ISDL) ranging from 10 to 100% for normal tissue were also analyzed. All SBRT plans for EDGE and CK met the dose constraints for PTV and OARs. For the PTV, the dosimetric metrics in EDGE plans were lower than that in CK, except that D99 and GI were slightly higher. The EDGE plans with lower CI, nCI and HI were superior to generate more conformal and homogeneous dose distribution for PTV. For the normal tissue, the CK plans were better at OARs sparing. The radiobiological indices EUD of spinal cord, duodenum, stomach, and kidneys were lower for CK plans, except that liver were higher. The volumes of normal tissue covered by medium ISDLs (with range of 20–70%) were lower for CK plans while that covered by high and low ISDLs were lower for EDGE plans. This study indicated that both EDGE and CK generated equivalent plan quality, and both systems can be considered as beneficial techniques for SBRT of pancreatic cancer. EDGE plans offered more conformal and homogeneous dose distribution for PTV, while the CK plans could minimize the exposure of OARs.

scholarly journals CyberKnife and EDGE in stereotactic body radiotherapy for pancreas cancer: a comparison of plan quality

2020 ◽  
Author(s):  
Zhitao Dai ◽  
Li Ma ◽  
Tingting Cao ◽  
Lian Zhu ◽  
Man Zhao ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Stereotactic Body Radiotherapy ◽  
Normal Tissue ◽  
Pancreas Cancer ◽  
Target Volume ◽  
Conformity Index ◽  
Equivalent Uniform Dose ◽  
Dose Distributions ◽  
Dose Volume ◽  
Comprehensive Comparison

Abstract Purpose: To perform a comprehensive comparison of the different stereotactic body radiotherapy (SBRT) plans between the Varian EDGE and CyberKnife (CK) systems for pancreas cancer.Materials and methods: Fifteen patients with pancreas cancer were selected in this study. The median planning target volume (PTV) was 28.688cm 3 (5.736 to 49.246 cm 3 ). The SBRT plans for the EDGE and CK were generated in the Eclipse and Multiplan systems respectively with the same contouring and dose constrains for PTV and organ at risk (OAR). Dose distributions in PTV were evaluated in terms of coverage, conformity index (CI), new conformity index (nCI), homogeneity index (HI), and gradient index (GI). OARs, including spinal cord, bowel, stomach, duodenum and kidneys were statistically evaluated by different dose-volume metrics and equivalent uniform dose (EUD) . The volume covered by the different isodose lines (ISDL) ranging from 10% to 100% for normal tissue were also analyzed.Results: All SBRT plans for EDGE and CK met the clinical requirement for PTV and OARs. . For the PTV, the dosimetric metrics in EDGE plans were lower than that in CK, except that D 99 and GI were slightly higher. The EDGE plans with lower CI , nCI and HI were superior to offer the better conformity and homogeneity for PTV. For the normal tissue, the CK plans were better at OARs sparing. The radiobiological indices EUD of spinal cord, duodenum, stomach, and kidneys were lower for CK plans, except that liver were higher. The volumes of normal tissue covered by medium ISDLs (with range of 20%~70%) were lower for CK plans while that covered by high and low ISDLs were lower for EDGE plans.Conclusions: This study indicated that both EDGE and CK generated equivalent plan quality, and both systems can be considered as beneficial techniques for SBRT of pancreas cancer. EDGE plans offered the better conformity and homogeneity of dose distributions for PTV, while the CK plans could minimize the exposure of OARs.

The potential of shape-based treatment plan optimization for pancreatic IMRT treatments to spare organs at risk and allow for dose escalation to the tumor PTV.

2011 ◽  
Vol 29 (4_suppl) ◽  
pp. 316-316
Author(s):  
S. F. Petit ◽  
B. Wu ◽  
M. Kazhdan ◽  
A. Dekker ◽  
P. Simari ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
At Risk ◽  
Normal Tissue ◽  
Organs At Risk ◽  
Treatment Plan ◽  
Spatial Relation ◽  
Pancreatic Cancer Patient ◽  
Target Volume ◽  
Plan Optimization ◽  
Treatment Plan Optimization

316 Background: Due to the low dose tolerance of the organs at risk (OARs) in the abdomen the tumor dose for pancreatic cancer patient is restricted to 50-60 Gy in 1.8-2.0 Gy fractions when combined with chemotherapy. The goal of this study was to develop a system that can determine the minimal radiation dose to the OARs of each individual patient that is achievable while maintaining adequate tumor coverage. This could guide treatment planners to spare the OARs to the fullest extent. When the minimal doses to the OAR are achieved, the total plan can be upscaled until the normal tissue dose constraints are met, allowing for an increase in tumor dose without increased normal tissue toxicity. Methods: The minimal achievable dose to the OARs depends on its proximity to the planning target volume (PTV). The overlap volume histogram (OVH) was used to describe the spatial relation of each OAR to the PTV. A database of 33 patients, treated with IMRT, was queried to find the lowest achieved dose to an organ for any of the prior patients with less favorable PTV-OAR configurations than the current patient. This minimal dose must also be achievable for the OAR of the new patient. For 25 randomly chosen patients the lowest achievable dose to the liver and kidneys was predicted this way. Then the patients were replanned to verify if this dose could be achieved. The new plans were compared to the original clinical plans. Results: After replanning the predicted achievable dose to the liver was realized within 1 and 2 Gy for more than 86% and 96% of the patients respectively. For the kidneys these numbers were 83% and 96%. The average improvement in terms of mean dose was 1.4 Gy (range 0 – 4.6 Gy) for the liver and 1.7 Gy (range 0 – 6.3 Gy) for the kidneys. This would have allowed an increase in PTV dose of on average 5 Gy (range 0-13 Gy) based on the liver and 8.5 Gy (range 0-38 Gy) based on the kidneys compared to the original plan, without an increase in dose to the bowel, cord, and stomach. Conclusions: The lowest achievable dose to the OARs could accurately be predicted for pancreatic cancer patients within seconds. This can guide dosimetrists to spare the OARs or increase the PTV dose by 5 Gy without increased toxicity. [Table: see text]

scholarly journals Dosimetric Feasibility Study of Dose Escalated Stereotactic Body Radiation Therapy (SBRT) in Locally Advanced Pancreatic Cancer (LAPC) Patients: It Is Time to Raise the Bar

2020 ◽  
Vol 10 ◽  
Author(s):  
Renzo Mazzarotto ◽  
Nicola Simoni ◽  
Stefania Guariglia ◽  
Gabriella Rossi ◽  
Renato Micera ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Organs At Risk ◽  
Locally Advanced ◽  
Volumetric Modulated Arc Therapy ◽  
Advanced Pancreatic Cancer ◽  
Locally Advanced Pancreatic Cancer ◽  
Conformity Index ◽  
Breath Hold ◽  
Prescription Dose ◽  
Dose Constraints

Background and ObjectiveTo assess the dosimetric feasibility of a stereotactic body radiotherapy (SBRT) dose escalated protocol, with a simultaneous integrated boost (SIB) and a simultaneous integrated protection (SIP) approach, in patients with locally advanced pancreatic cancer (LAPC).Material and MethodsTwenty LAPC lesions, previously treated with SBRT at our Institution, were re-planned. The original prescribed and administered dose was 50/30/25 Gy in five fractions to PTVsib (tumor-vessel interface [TVI])/PTVt (tumor volume)/PTVsip (overlap area between PTVt and planning organs at risk volume [PRVoars]), respectively. At re-planning, the prescribed dose was escalated up to 60/40/33 Gy in five fractions to PTVsib/PTVt/PTVsip, respectively. All plans were performed using an inspiration breath hold (IBH) technique and generated with volumetric modulated arc therapy (VMAT). Well-established and accepted OAR dose constraints were used (D0.5cc < 33 Gy for luminal OARs and D0.5cc < 38 Gy for corresponding PRVoars). The primary end-point was to achieve a median dose equal to the prescription dose for the PTVsib with D98≥ 95% (95% of prescription dose is the minimum dose), and a coverage for PTVt and PTVsip of D95≥95%, with minor deviations in OAR dose constraints in < 10% of the plans.ResultsPTVsib median (± SD) dose/D95/conformity index (CI) were 60.54 (± 0.85) Gy/58.96 (± 0.86) Gy/0.99 (± 0.01), respectively; whilst PTVt median (± SD) dose/D95 were 44.51 (± 2.69) Gy/38.44 (± 0.82) Gy, and PTVsip median (± SD) dose/D95 were 35.18 (± 1.42) Gy/33.01 (± 0.84) Gy, respectively. With regard to OARs, median (± SD) maximum dose (D0.5cc) to duodenum/stomach/bowel was 29.31 (± 5.72) Gy/25.29 (± 6.90) Gy/27.03 (± 5.67) Gy, respectively. A minor acceptable deviation was found for a single plan (bowel and duodenum D0.5cc=34.8 Gy). V38 < 0.5 cc was achieved for all PRV luminal OARs.ConclusionsIn LAPC patients SBRT, with a SIB/SIP dose escalation approach up to 60/40/33 Gy in five fractions to PTVsib/PTVt/PTVsip, respectively, is dosimetrically feasible with adequate PTVs coverage and respect for OAR dose constraints.

scholarly journals Differential Dose Distribution in Transition from 3-D CRT to IMRT Treatment Plans for Glioblastoma Multiforme' at Stage III or IV: A Clinical Study of a Brain Tumor

2018 ◽  
Vol 19 (1) ◽  
pp. 64
Author(s):  
Sadiq R Malik ◽  
Shohel Reza ◽  
MM Shakhawat Hossain
Keyword(s):  
Radiation Therapy ◽  
Dose Distribution ◽  
Selection Process ◽  
Organs At Risk ◽  
Treatment Plan ◽  
Target Volume ◽  
Conformity Index ◽  
Tumor Control ◽  
Treatment Plans

<p><span>Advancement in Cancer Therapy Technology (CTT) due to Software, Hardware and precise delivery of radiation dose has enhanced the quality of life of cancer patients. This report aims at the application of 3-D CRT (Three Dimensional Conformal Radiation Therapy) and IMRT (Intensity Modulated Radiation Therapy) for a quality of treatment. Other anatomical sites viz. Prostate, Lung, etc. may also be treated provided a better tool is applied for target delineation for which FUSION of CT and MRI images are used to ascertain differences in tissue density. This Fusion image of 3 mm slices offer accurate contouring of the tumor. The oncologist and/or physicist perform delineation of (I) GTV (Gross Tumor Volume), (II) CTV (Clinical Target Volume), (III) PTV (Planning Target Volume), (IV) TV (Treated Volume) and (V) OARs (Organs at Risk). This is done to secure conformal dose distribution and justify the clinical objectives of Tumor Control Probability (TCP) by reducing the normal tissue complication probability (NTCP). <span> </span><span> </span>The implication of this study outlines the fundamental goal of effective treatment procedures by comparing treatment plans of 3-D CRT and IMRT. Tolerance levels of dose to different organs are optimized by the analysis of random and systemic geometrical deviations, margin on target volumes, conformity index (CI), patient selection process and, of course, the shape and stage of target. The comparative parameters of treatment plans are segmented and tabulated to implicate the application of necessary tools to decide on a treatment plan for similar patients.</span></p><p><span>Bangladesh J. Nuclear Med. 19(1): 64-67, January 2016</span></p>

scholarly journals An Investigation of Non-Coplanar Volumetric Modulated Radiation Therapy for Locally Advanced Unresectable Pancreatic Cancer Using a Trajectory Optimization Method

2021 ◽  
Vol 11 ◽  
Author(s):  
Gong Wang ◽  
Hao Wang ◽  
Hongqing Zhuang ◽  
Ruijie Yang
Keyword(s):  
Pancreatic Cancer ◽  
Spinal Cord ◽  
Optimization Algorithm ◽  
Trajectory Optimization ◽  
Locally Advanced ◽  
Advanced Pancreatic Cancer ◽  
Conformity Index ◽  
Unresectable Pancreatic Cancer ◽  
Least Cost Path ◽  
The Mean

PurposeThis study was conducted in order to develop a trajectory optimization algorithm for non-coplanar volumetric modulated arc therapy (VMAT) and investigate the potential of organs at risk (OARs) sparing in locally advanced pancreatic cancer patients using non-coplanar VMAT.Methods and MaterialsFirstly, a cost map that represents the ray–OAR voxel intersections at each source position was generated using a ray-tracing algorithm. A graph search algorithm was then used to determine the least-cost path from the cost map. Lastly, full arcs or partial arcs were selected based on the least-cost path to generate the non-coplanar VMAT (ncVMAT) trajectories. Clinical coplanar VMAT (coVMAT) plans for 11 patients diagnosed with locally advanced unresectable pancreatic cancer (LAPC) receiving 45 to 70 Gy in 25 fractions were replanned using non-coplanar VMAT trajectories. Both coplanar and non-coplanar plans were normalized to cover 95% of the PTV45 Gy volume with a prescription dose of 45 Gy. The conformity index (CI), homogeneity index (HI), PTV coverage, and dose to the OARs were compared between coVMAT and ncVMAT plans.ResultsWith ncVMAT, the mean coverage of PTV50 Gy, PTV54 Gy, PTV60 Gy, and PTV70 Gy increased significantly. The mean conformity index of PTV45 Gy, PTV54 Gy, and PTV70 Gy was also improved in the ncVMAT plans. Compared with coVMAT plans, the ncVMAT plans resulted in significantly lower doses to the spinal cord, bilateral kidneys, stomach, and duodenum. The maximum dose to the spinal cord decreased by 6.11%. The mean dose to the left and right kidneys decreased by an average of 5.52% and 11.71%, respectively. The Dmax, Dmean, and D15% of the stomach were reduced by an average of 7.45%, 15.82%, and 16.79%, separately. The D15% and Dmean of the duodenum decreased 6.38% and 5.64%, respectively.ConclusionA trajectory optimization algorithm was developed for non-coplanar VMAT. Compared with conventional coplanar VMAT, non-coplanar VMAT resulted in improved coverage and conformity to the targets. The sparing of OARs was significantly improved in non-coplanar VMAT compared with coVMAT plans for locally advanced pancreatic cancer.

Normal-tissue toxicities of thoracic radiation therapy: esophagus, lung, and spinal cord as organs at risk

2004 ◽  
Vol 18 (1) ◽  
pp. 131-160 ◽  
Author(s):  
Maria Werner-Wasik ◽  
Xiaoli Yu ◽  
Lawrence B Marks ◽  
Timothy E Schultheiss
Keyword(s):  
Spinal Cord ◽  
At Risk ◽  
Radiation Therapy ◽  
Normal Tissue ◽  
Organs At Risk ◽  
Thoracic Radiation

scholarly journals Role of Stereotactic Body Radiotherapy in the Treatment of Elderly and Poor Performance Status Patients With Pancreatic Cancer

2017 ◽  
Vol 13 (3) ◽  
pp. 157-166 ◽  
Author(s):  
Lauren M. Rosati ◽  
Joseph M. Herman
Keyword(s):  
Pancreatic Cancer ◽  
Stereotactic Body Radiotherapy ◽  
Group Performance ◽  
Performance Status ◽  
Single Agent ◽  
Locally Advanced ◽  
Poor Performance ◽  
Tumor Control ◽  
Poor Performance Status ◽  
Patient Reported

Literature on the management of nonmetastatic pancreatic ductal adenocarcinoma in patients who are elderly or have poor performance status is sparse. The median survival of this unique cohort of patients is < 6 months, and most patients are only offered single-agent gemcitabine or supportive care. Recently, adding nanoparticle albumin-bound paclitaxel to gemcitabine was shown to improve survival of patients with metastatic disease with Eastern Cooperative Group performance status of 2. Although standard chemoradiotherapy provides long-term locoregional control in locally advanced pancreatic cancer, it is difficult for this group of patients to tolerate 6 weeks of therapy. Stereotactic body radiotherapy (SBRT) can be delivered in only 3 to 5 days, does not require concurrent chemotherapy, and has limited toxicity, and tumor control rates appear to be equivalent to or better than those achieved with standard chemoradiotherapy. Additionally, SBRT has been shown to improve cancer-related pain and patient-reported quality of life. Given the favorable toxicity profile, SBRT seems like an obvious choice for patients who are elderly, have multiple comorbidities, or have poor performance status. Herein, we review the literature on SBRT in this unique patient population and discuss future directions.

scholarly journals Stereotactic body radiotherapy for locally-advanced unresectable pancreatic cancer—patterns of care and overall survival

2017 ◽  
Vol 8 (5) ◽  
pp. 766-777 ◽  
Author(s):  
Michael J. Dohopolski ◽  
Scott M. Glaser ◽  
John A. Vargo ◽  
Goundappa K. Balasubramani ◽  
Sushil Beriwal
Keyword(s):  
Pancreatic Cancer ◽  
Overall Survival ◽  
Stereotactic Body Radiotherapy ◽  
Locally Advanced ◽  
Patterns Of Care ◽  
Unresectable Pancreatic Cancer

scholarly journals Dose-Volume Comparison of IMRT and PSPT Treatment Plans for Early-Stage Glottic Cancer

2020 ◽  
Vol 7 (2) ◽  
pp. 42-50
Author(s):  
Takahiro Kato ◽  
Nobukazu Fuwa ◽  
Masao Murakami
Keyword(s):  
Spinal Cord ◽  
Dose Distribution ◽  
Early Stage ◽  
Organs At Risk ◽  
Cricoid Cartilage ◽  
Thyroid Cartilage ◽  
Target Volume ◽  
Glottic Cancer ◽  
Volume Comparison ◽  
Prescription Dose

Abstract Purpose To clarify the dose distribution characteristics for early-stage glottic cancer by comparing the dose distribution between intensity-modulated radiation therapy (IMRT) and passive scattering proton therapy (PSPT) and to examine the usefulness of PSPT for early-stage glottic cancer. Materials and Methods Computed tomography datasets of 8 patients with T1-2 glottic cancer who had been treated by PSPT were used to create an IMRT plan in Eclipse with 7 fields and a PSPT plan in XiO-M with 2 fields. Organs at risk (OARs) included the carotid arteries, arytenoids, inferior constrictor muscles, strap muscles, thyroid cartilage, cricoid cartilage, and spinal cord. The prescription dose was 66 GyRBE in 33 fractions to the planning target volume (PTV). All plans were optimized such that 95% of the PTV received 90% of the prescription dose considering that the skin was slightly spared. Results The superiority of the PSPT was confirmed in all OARs. In the PSPT, the dose to the contralateral carotid artery and the spinal cord, which is slightly distant from the PTV, was dramatically reduced while maintaining the dose distribution uniformity of the PTV by comparison with IMRT. Conclusion PSPT for early-stage glottic cancer resulted in good target dose homogeneity and significantly spared the OARs as compared with the IMRT. PSPT is expected to be effective in reducing late effects and particularly useful for young people.

scholarly journals Clinical Validation and Treatment Plan Evaluation Based on Auto-Delineation of the Clinical Target Volume for Prostate Cancer Radiotherapy

2022 ◽  
Author(s):  
Jing Shen ◽  
Yinjie TAO ◽  
Hui GUAN ◽  
Hongnan ZHEN ◽  
Lei HE ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
At Risk ◽  
Organs At Risk ◽  
Treatment Plan ◽  
Statistical Significance ◽  
Locally Advanced ◽  
Target Volume ◽  
Ct Scans ◽  
Dice Similarity Coefficient ◽  
Treatment Plans

Abstract Purpose Clinical target volumes (CTV) and organs at risk (OAR) could be auto-contoured to save workload. The goal of this study was to assess a convolutional neural network (CNN) for totally automatic and accurate CTV and OAR in prostate cancer, while also comparing anticipated treatment plans based on auto-contouring CTV to clinical plans. Methods From January 2013 to January 2019, 217 computed tomography (CT) scans of patients with locally advanced prostate cancer treated at our hospital were collected and analyzed. CTV and OAR were delineated with a deep learning based method, which named CUNet. The performance of this strategy was evaluated using the mean Dice similarity coefficient (DSC), 95th percentile Hausdorff distance (95HD), and subjective evaluation. Treatment plans were graded using predetermined evaluation criteria, and % errors for clinical doses to the planned target volume (PTV) and organs at risk(OARs) were calculated. Results The defined CTVs had mean DSC and 95HD values of 0.84 and 5.04 mm, respectively. For one patient's CT scans, the average delineation time was less than 15 seconds. When CTV outlines from CUNetwere blindly chosen and compared to GT, the overall positive rate in clinicians A and B was 53.15% vs 46.85%, and 54.05% vs 45.95%, respectively (P>0.05), demonstrating that our deep machine learning model performed as good as or better than human demarcation Furthermore, 8 testing patients were chosen at random to design the predicted plan based on the auto-courtoring CTV and OAR, demonstrating acceptable agreement with the clinical plan: average absolute dose differences of D2, D50, D98, Dmean for PTV are within 0.74%, and average absolute volume differences of V45, V50 for OARs are within 3.4%. Without statistical significance (p>0.05), the projected findings are comparable to clinical truth. Conclusion The experimental results show that the CTV and OARs defined by CUNet for prostate cancer were quite close to the ground reality.CUNet has the potential to cut radiation oncologists' contouring time in half. When compared to clinical plans, the differences between estimated doses to CTV and OAR based on auto-courtoring were small, with no statistical significance, indicating that treatment planning for prostate cancer based on auto-courtoring has potential.

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