A study on the tumor volume computation between different 3D treatment planning systems in radiotherapy

Prabhakar, R; Rath, Goura Kishor; Haresh, K.P.; Manoharan, N; Laviraj, M.A.; Rajendran, Mythilypriya; Julka, Pramod Kumar

doi:10.4103/0973-1482.82917

Cited by 13 publications

(8 citation statements)

References 17 publications

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“…Tumor height and brain height were measured on the post‐contrast CT image slice on which the tumor was the largest using the measuring tool . The various volumes used in the study for tumor and brain were measured using the volume measuring tool in the planning systems . The gross tumor volume:brain volume and planning target volume:brain volume were then calculated.…”

Section: Methodsmentioning

confidence: 99%

Long‐term survival with stereotactic radiotherapy for imaging‐diagnosed pituitary tumors in dogs

Hansen

Zwingenberger

Théon

et al. 2018

Vet Radiology Ultrasound

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Published studies on the use of stereotactic radiotherapy for dogs with pituitary tumors are limited. This retrospective observational study describes results of stereotactic radiotherapy for 45 dogs with imaging-diagnosed pituitary tumors. All dogs were treated at a single hospital during the period of December 2009-2015. The stereotactic radiotherapy was delivered in one 15 Gray (Gy) fraction or in three 8 Gy fractions. At the time of analysis, 41 dogs were deceased.Four were alive and censored from all survival analyses; one dog received 8 Gy every other day and was removed from protocol analyses. The median overall survival from first treatment was 311 days (95% confidence interval 226-410 days [range 1-2134 days]). Thirty-two dogs received 15 Gy (median overall survival 311 days; 95% confidence interval [range 221-427 days]), and 12 received 24 Gy on three consecutive days (median overall survival 245 days, 95% confidence interval [range 2-626 days]). Twenty-nine dogs had hyperadrenocorticism (median overall survival 245 days), while 16 had nonfunctional masses (median overall survival 626 days). Clinical improvement was reported in 37/45 cases. Presumptive signs of acute adverse effects within 4 months of stereotactic radiotherapy were noted in 10/45, and most had improvement spontaneously or with steroids. Late effects versus tumor progression were not discernable, but posttreatment blindness (2), hypernatremia (2), and progressive neurological signs (31) were reported.There was no statistical difference in median overall survival for different protocols. Patients with nonfunctional masses had longer median overall survival than those with hyperadrenocorticism (P = 0.0003). Survival outcomes with stereotactic radiotherapy were shorter than those previously reported with definitive radiation, especially for dogs with hyperadrenocorticism. K E Y W O R D SCushing's disease, hyperadrenocorticism, photon therapy, SRS, stereotaxis three-dimensional-conformal fields, or with a cone-based system for beam collimation. 17,18,25 There is one study of 51 dogs with

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Section: Methodsmentioning

confidence: 99%

Long‐term survival with stereotactic radiotherapy for imaging‐diagnosed pituitary tumors in dogs

Hansen

Zwingenberger

Théon

et al. 2018

Vet Radiology Ultrasound

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“…The authors considered deviances of ± 2% of PCI as “nearly equal”; effects of similar order could occur due to dose grid effects and effects of digitization (voxel generation) of a spherical object (see [15] for volume effects of structure definition). Thus, only for a PTV diameter of 1.0 cm and a SID of 100 cm, the PCI differed markedly for MLC compared with circular collimator (Table 1).…”

Section: Resultsmentioning

confidence: 99%

Finer leaf resolution and steeper beam edges using a virtual isocentre in concurrence to PTV-shaped collimators in standard distance – a planning study

et al. 2017

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PurposeInvestigation of a reduced source to target distance to improve organ at risk sparing during stereotactic irradiation (STX).MethodsThe authors present a planning study with perfectly target-volume adapted collimator compared with multi-leaf collimator (MLC) at reduced source to virtual isocentre distance (SVID) in contrast to normal source to isocentre distance (SID) for stereotactic applications. The role of MLC leaf width and 20–80% penumbra was examined concerning the healthy tissue sparing. Several prescription schemes and target diameters are considered.ResultsPaddick’s gradient index (GI) as well as comparison of the mean doses to spherical shells at several distances to the target is evaluated. Both emphasize the same results: the healthy tissue sparing in the high dose area around the planning target volume (PTV) is improved at reduced SVID ≤ 70 cm. The effect can be attributed more to steeper penumbra than to finer leaf resolution. Comparing circular collimators at different SVID just as MLC-shaped collimators, always the GI was reduced. Even MLC-shaped collimator at SVID 70 cm had better healthy tissue sparing than an optimal shaped circular collimator at SID 100 cm.Regarding penumbra changes due to varying SVID, the results of the planning study are underlined by film dosimetry measurements with Agility™ MLC.ConclusionPenumbra requires more attention in comparing studies, especially studies using different planning systems. Reduced SVID probably allows usage of conventional MLC for STX-like irradiations.Electronic supplementary materialThe online version of this article (doi:10.1186/s13014-017-0826-8) contains supplementary material, which is available to authorized users.

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“…In this paper they have separately contoured on each planning systems. Prabhakar et al 15 assessed on the variation of Tumor volume between different treatment planning systems. The tumor volume for normal IMRT and IGRT in head and neck is generally greater than 300 cc but the OARs in this region ranges between 0.1 cc (e.g.…”

Section: Discussionmentioning

confidence: 99%

A prospective study of OAR volume variations between two different treatment planning systems in radiotherapy

Sharma

Hansen

et al. 2015

Int J Cancer Ther Oncol

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It has been seen that there is a clinically significant variation in the volume calculated across different planning systems for the same digital imaging and communication (DICOM) contours. Aim: The purpose of this study is to investigate the difference in volumes of organs at risk when the structure sets were exported from the Eclipse ((Palo Alto, USA Version 10.0) to XIO CMS (Electa, Crawley, UK Version 4.40.00) treatment planning system (TPS) and identify how the differences occur. Methods: We prospectively analyzed the volumes of organs at risk from computerized tomography (CT) data of 54 patients. Head and neck and brain tumors were taken for this study and contoured on Eclipse treatment planning system (TPS) after importing images from CT. These contoured images were then exported using radiotherapy DICOM transfer facility to XIO CMS planning system and compared the contoured volumes with Eclipse TPS structured volumes. Results: Our analysis showed that the differences in calculated volumes of the contours for the patients between the two planning systems can be large. Mixed results are shown for different organs with the absolute volume difference ranging from-0.25 cc to 319.73 cc. These results clearly shown that the two TPS interprets the contours differently when calculating the volume, and there is a closer match with the theoretical calculated volumes with XIO CMS calculated volumes. Conclusion: Observed discrepancies were consistent between the two planning systems. This impact of contouring variability could play a role on plan quality metrics which is used as criteria for clinical trial protocol compliance.

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A study on the tumor volume computation between different 3D treatment planning systems in radiotherapy

Abstract: The study shows that all the treatment planning systems showed variation in computing the tumor volume and the CTV to PTV generation also varied with the planning systems.

Cited by 13 publications

References 17 publications

Long‐term survival with stereotactic radiotherapy for imaging‐diagnosed pituitary tumors in dogs

Long‐term survival with stereotactic radiotherapy for imaging‐diagnosed pituitary tumors in dogs

Finer leaf resolution and steeper beam edges using a virtual isocentre in concurrence to PTV-shaped collimators in standard distance – a planning study

A prospective study of OAR volume variations between two different treatment planning systems in radiotherapy

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