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Japanese Journal of Radiology
Published in: Japanese Journal of Radiology 6/2017

01-06-2017 | Technical Note

Modifying the planning target volume to optimize the dose distribution in dynamic conformal arc therapy for large metastatic brain tumors

Authors: Kengo Ogura, Yasuhiro Kosaka, Toshiyuki Imagumbai, Kazuhito Ueki, Ryo Narukami, Takayuki Hattori, Masaki Kokubo

Published in: Japanese Journal of Radiology | Issue 6/2017

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Abstract

Purpose

When treating large metastatic brain tumors with stereotactic radiotherapy (SRT), high dose conformity to target is difficult to achieve. Employing a modified planning target volume (mPTV) instead of the original PTV may be one way to improve the dose distribution in linear accelerator-based SRT using a dynamic conformal technique. In this study, we quantitatively analyzed the impact of a mPTV on dose distribution.

Materials and methods

Twenty-four tumors with a maximum diameter of >2 cm were collected. For each tumor, two plans were created: one used a mPTV and the other did not. The mPTV was produced by shrinking or enlarging the original PTV according to the dose distribution in the original plan. The dose conformity was evaluated and compared between the plans using a two-sided paired t test.

Results

The conformity index defined by the Radiation Therapy Oncology Group was 1.34 ± 0.10 and 1.41 ± 0.13, and Paddick’s conformity index was 0.75 ± 0.05 and 0.71 ± 0.06, for the plans with and without a mPTV, respectively. All of these improvements were statistically significant (P < 0.05).

Conclusion

The use of a mPTV can improve target conformity when planning SRT for large metastatic brain tumors.
Literature
1.
Linskey ME, Andrews DW, Asher AL, Burri SH, Kondziolka D, Robinson PD, et al. The role of stereotactic radiosurgery in the management of patients with newly diagnosed brain metastases: a systematic review and evidence-based clinical practice guideline. J Neurooncol. 2010;96:45–68.CrossRefPubMed
2.
Shaw E, Scott C, Souhami L, Dinapoli R, Kline R, Loeffler J, et al. Single dose radiosurgical treatment of recurrent previously irradiated primary brain tumors and brain metastases: final report of RTOG protocol 90-05. Int J Radiat Oncol Biol Phys. 2000;47:291–8.CrossRefPubMed
3.
Ernst-Stecken A, Ganslandt O, Lambrecht U, Sauer R, Grabenbauer G. Phase II trial of hypofractionated stereotactic radiotherapy for brain metastases: results and toxicity. Radiother Oncol. 2006;81:18–24.CrossRefPubMed
4.
Minniti G, Clarke E, Lanzetta G, Osti MF, Trasimeni G, Bozzao A, et al. Stereotactic radiosurgery for brain metastases: analysis of outcome and risk of brain radionecrosis. Radiat Oncol. 2011;6:48.CrossRefPubMedPubMedCentral
5.
Minniti G, Scaringi C, Paolini S, Lanzetta G, Romano A, Cicone F, et al. Single-fraction versus multifraction (3 × 9 Gy) stereotactic radiosurgery for large (>2 cm) brain metastases: a comparative analysis of local control and risk of radiation-induced brain necrosis. Int J Radiat Oncol Biol Phys. 2016;95:1142–8.CrossRefPubMed
6.
Shaw E, Kline R, Gillin M, Souhami L, Hirschfeld A, Dinapoli R, et al. Radiation Therapy Oncology Group: radiosurgery quality assurance guidelines. Int J Radiat Oncol Biol Phys. 1993;27:1231–9.CrossRefPubMed
7.
Paddick I, Lippitz B. A simple dose gradient measurement tool to complement the conformity index. J Neurosurg. 2006;105(Suppl):194–201.PubMed
8.
Kanda Y. Investigation of the freely available easy-to-use software ‘EZR’ for medical statistics. Bone Marrow Transplant. 2013;48:452–8.CrossRefPubMed
9.
Monk JE, Perks JR, Doughty D, Plowman PN. Comparison of a micro-multileaf collimator with a 5-mm-leaf-width collimator for intracranial stereotactic radiotherapy. Int J Radiat Oncol Biol Phys. 2003;57:1443–9.CrossRefPubMed
10.
Dhabaan A, Elder E, Schreibmann E, Crocker I, Curran WJ, Oyesiku NM, et al. Dosimetric performance of the new high-definition multileaf collimator for intracranial stereotactic radiosurgery. J Appl Clin Med Phys. 2010;11:197–211.CrossRef
11.
Burghelea M, Verellen D, Gevaert T, Depuydt T, Poels K, Simon V, et al. Feasibility of using the Vero SBRT system for intracranial SRS. J Appl Clin Med Phys. 2014;15:4437.CrossRefPubMed
12.
Serna A, Puchades V, Mata F, Ramos D, Alcaraz M. Influence of multi-leaf collimator leaf width in radiosurgery via volumetric modulated arc therapy and 3D dynamic conformal arc therapy. Phys Med. 2015;31:293–6.CrossRefPubMed
13.
Audet C, Poffenbarger BA, Chang P, Jackson PS, Lundahl RE, Ryu SI, et al. Evaluation of volumetric modulated arc therapy for cranial radiosurgery using multiple noncoplanar arcs. Med Phys. 2011;38:5863–72.CrossRefPubMed
14.
Molinier J, Kerr C, Simeon S, Ailleres N, Charissoux M, Azria D, et al. Comparison of volumetric-modulated arc therapy and dynamic conformal arc treatment planning for cranial stereotactic radiosurgery. J Appl Clin Med Phys. 2016;17:5677.CrossRefPubMed
15.
Ogura K, Mizowaki T, Ishida Y, Hiraoka M. Dosimetric advantages of O-ring design radiotherapy system for skull-base tumors. J Appl Clin Med Phys. 2014;15:4608.CrossRefPubMed
16.
Ohtakara K, Hayashi S, Tanaka H, Hoshi H. Dosimetric comparison of 2.5 vs. 3.0 mm leaf width micro-multileaf collimator-based treatment systems for intracranial stereotactic radiosurgery using dynamic conformal arcs: implications for treatment planning. Jpn J Radiol. 2011;29:630–8.CrossRefPubMed
17.
Ohtakara K, Hayashi S, Hoshi H. The relation between various conformity indices and the influence of the target coverage difference in prescription isodose surface on these values in intracranial stereotactic radiosurgery. Br J Radiol. 2012;85:e223–8.CrossRefPubMedPubMedCentral
18.
Ohtakara K, Hayashi S, Tanaka H, Hoshi H. Consideration of optimal isodose surface selection for target coverage in micro-multileaf collimator-based stereotactic radiotherapy for large cystic brain metastases: comparison of 90, 80 and 70% isodose surface-based planning. Br J Radiol. 2012;85:e640–6.CrossRefPubMedPubMedCentral
Metadata
Title
Modifying the planning target volume to optimize the dose distribution in dynamic conformal arc therapy for large metastatic brain tumors
Authors
Kengo Ogura
Yasuhiro Kosaka
Toshiyuki Imagumbai
Kazuhito Ueki
Ryo Narukami
Takayuki Hattori
Masaki Kokubo
Publication date
01-06-2017
Publisher
Springer Japan
Published in
Japanese Journal of Radiology / Issue 6/2017
Print ISSN: 1867-1071
Electronic ISSN: 1867-108X
DOI
https://doi.org/10.1007/s11604-017-0639-6

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