Differences in Target Volume Delineation Using Typical Radiosurgery Planning System

Su Chul Han; Dong Joon Lee

doi:10.14316/pmp.2013.24.4.265

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Han and Lee: Differences in Target Volume Delineation Using Typical Radiosurgery Planning System

Original Article

Progress in Medical Physics 2013;24(4):265-270.

Published online: 17 December 2013

DOI: https://doi.org/10.14316/pmp.2013.24.4.265

Differences in Target Volume Delineation Using Typical Radiosurgery Planning System

Su Chul Han^∗,^†, Dong Joon Lee^‡

^∗Radiological Cancer Medicine, University of Science and Technology, Daejeon, Korea

^†Research Center for Radiotherapy, Korea Institute of Radiological and Medical Sciences, Seoul, Korea

^†Department of Neurosurgery, Ilsan Paik Hospital, College of Medicine, Inje University, Goyang, Korea

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Correct target volume delineation is an important part of radiosurgery treatment planning process. We designed head phantom and performed target delineation to evaluate the volume differences due to radiosurgery treatment planning systems and image acquisition system, CT/MR. Delineated mean target volume from CT scan images was 2.23±0.08 cm³ on BrainSCAN (NOVALS), 2.13±0.07 cm³ on Leksell gamma plan (Gamma Knife) and 2.24±0.10 cm³ on Multi plan (Cyber Knife). For MR images, 2.08±0.06 cm³ on BrainSCAN, 1.94±0.05 cm³ on Leksell gamma plan and 2.15±0.06 cm³ on Multi plan. As a result, Differences of delineated mean target volume due to radiotherapy planning system was 3% to 6%. And overall mean target volume from CT scan images was 6.36% larger than those of MR scan images.

Keywords: Target volume delineation, Radiosurgery planning system

REFERENCES

1. Klein EE, Hanley J, Bayouth J, et al. Task Group 142 report: Quality assurance of medical accelerators. Med Phys. 36(9):4197–4212. 2009.

2. Kutcher GJ, Coia L, Gillin M, Hanson WF, et al. Comprehensive QA for radiation oncology: Report of AAPM Radiation Therapy Committee Task Group 40. Med Phys. 21(4):581–618. 1994.

3. Robar JL, Clark BG. The use of radiographic film for linear accelerator stereotactic radiosurgical dosimetry. Med Phys. 26(10):2144–2150. 1999.

4. 이경남, 이동준, 서태석. 자기공명영상기반 겔 선량측정법을 이용한 3차원적 목표 중심점 점검기술. 의학물리. 22(1):35–41. 2011.

5. Mazzara GP, Velthuizen RP, Pearlman JL, et al. Brain tumor target volume determination for radiation treatment planning through automated MRI segmentation. Int J Radia Oncol Biol Phys. 59(1):300–312. 2004.

6. Rasch C, Keus R, Pameijer FA, et al. The potential impact of CT-MRI matching on tumor volume delineation in advanced head and neck cancer. Int J Radia Oncol Biol Phys. 39(4):841–848. 1997.

7. Caldwell CB, Mah K, Ung YC, et al. Observer variation in contouring gross tumor volume in patients with poorly defined Non-small-cell lung tumors on CT: The impact of 18FDG-hybrid pet fusion. Int J Radia Oncol Biol Phys. 51(4):923–931. 2001.

8. Kouwenhoven E, Giezen M, Struikmans H. Measuring the similarity of target volume delineations independent of the number of observers. Phys Med Bio. 54(9):2863–2873. 2009.

9. Weltens C, Menten J, Feron M, et al. Interobserver variation in gross tumor volume delineation of brain tumor on computed tomography and impact of magnetic resonance imaging. Radiotherapy & Oncology. 60(1):49–59. 2001.

10. Breen SL, Publicover J, De Silva S, et al. Intraobserver and Interobserver variability in GTV Delineation on FDG-PETCT images of Head and Neck Cancers. Int J RadiaOncol- BiolPhys. 68(3):763–770. 2007.

11. Geets X, Daisne JF, Tomsej M, et al. Impact of the type of imaging modality on target volumes delineation and dose distribution in Pharyngo-laryngeal squamous cell carcinoma: comparison between pre- and per treatment studies. Radiotherapy & Oncology. 78(3):291–297. 2006.

12. Ackerly T, Andrews J, Ball D, et al. Discrepancies in volume calculations between different radiotherapy treatment planning systems: Australas Phys Eng Sci Med. 26(2):91–93. 2003.

Fig. 1.

Small target volume location in custom designed head phantom. (a) Axial view. (b) Oblique view.

Fig. 2.

The axial phantom image from acquired MRI (a) and CT (b).

Fig. 3.

Comparison of small target volume acquired from (a) CT image (b) MRI Image depends on radiotherapy planning system.

Fig. 4.

Comparison of small target volume in radiotherapy planning system depends on image acquisition system (CT1, MRI1: BrainSCAN, CT2, MRI2: Leksell gamma plan, CT3, MRI3: Multi plan).

Table 1.

CT/MR image acquisition protocol for evaluate the delineated small target volume.

	CT	MRI
Slice thickness	2.0 mm	2.0 mm
Inter slice gap	Not gap	No gap
Field of View (FOV)	379 mm×379 mm	250 mm×250 mm
Matrix size	512×512	512×512
TR/TE		5,631 ms/105 ms
Coil		Head coil used

Table 2.

Delineated mean target volume from CT/MR scan images in radiosurgery planning system. (Mean±S.D) cm³

	CT	Diff. (%)^∗	MRI	Diff. (%)^∗
BrainSCAN (Novalis)	2.23±0.08		2.08±0.06
Leksell gamma plan (Gamma knife)	2.13±0.07	−4.48%	1.94±0.05	6.73%
Multi plan (Cyber knife)	2.24±0.10	−0.45%	2.15±0.06	－3.36%
Mean	2.20±0.08		2.06±0.06
Diff. (%) (CT_mean/MR_mean)		6.36%

^∗ Difference (%) is mean difference of delineated target volume between BrainSCAN and Leksell gamma plan (or Multi plan).

Table 3.

Target volume differences between CT/MR delineation depend on radiotherapy planning system.

	Mean diff. (cm³)	p-value (both)	95% CI of the difference
	Mean diff. (cm³)	p-value (both)	Lower	Upper
BrainSCAN (Novalis)	0.15	0.000	0.12	0.19
Leksell gamma plan (Gamma knife)	0.19	0.000	0.16	0.22
Multi plan (Cyber knife)	0.09	0.000	0.04	0.13

Table 4.

Target volume differences depend on acquired CT/MRI.

		Mean diff. (cm³)	p-value (both)	95% CI of the difference
		Mean diff. (cm³)	p-value (both)	Lower	Upper
CT₁ _(vs.)	CT₂	0.10	0.000	0.05	0.015
	CT₃	－0.01	0.940	－0.06	－0.047
CT₂ _(vs.)	CT₁	－0.10	0.000	－0.16	－0.046
	CT₃	0.11	0.000	－0.16	－0.05
CT₃ _(vs.)	CT₁	0.01	0.940	－0.05	0.06
	CT₂	0.11	0.000	0.05	0.16
MRI₁ _(vs.)	MRI₂	0.01	0.000	0.10	0.18
	MRI₃	－0.07	0.000	－0.11	－0.03
MRI₂ _(vs.)	MRI₁	－0.14	0.000	－0.18	0.10
	MRI₃	－0.21	0.000	－0.25	－0.17
MRI₃ _(vs.)	MRI₁	0.07	0.000	0.03	0.11
	MRI₂	0.21	0.000	0.17	0.25

CT₁, MRI₁: BrainSCAN, CT₂, MRI₂: Leksell gamma plan, CT₃, MRI₃: Multi plan.

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