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Practical collimator optimization in the management of prostate IMRT planning: A feasibility study

Published online by Cambridge University Press:  27 June 2011

M Ahamed Badusha  and
CK McGarry
M Ahamed Badusha*
Affiliation:
Radiotherapy Physics Department, Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Belfast, Northern Ireland, UK
CK McGarry
Affiliation:
Radiotherapy Physics Department, Northern Ireland Cancer Centre, Belfast Health and Social Care Trust, Belfast, Northern Ireland, UK Centre for Cancer Research and Cell Biology, Queen’s University Belfast, Belfast, Northern Ireland, UK
*
Correspondence to: M. Ahamed Badusha M.Sc MIPEM, Clinical Scientist, Radiotherapy Physics Service, Northern Ireland Cancer Centre, Belfast Health & Social Care Trust, Lisburn Road, Belfast BT9 7AB, Northern Ireland, UK. E-mail: [email protected]
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Abstract

The objective of this study was to evaluate the delivery efficiency of intensity modulated radiation therapy (IMRT) with a non-zero collimator rotation approach compared to conventional planning IMRT in the management of prostate carcinoma. Inverse plans, created using conventional collimator angle 0° (CA0) for eight prostate patients, were compared to plans using collimator angle 70° (CA70) for all fields and also with plans utilizing an automatic collimator angle optimization tool (CAopt) for each field. Results demonstrate that IMRT plans created with rotational collimator techniques can produce comparable dose distributions to standard CA0 plans. The rotational collimator approach significantly reduced the total number of monitor units (MU) by 6% (p value = 0.027) and 9% (p value = 0.003) for CA70 and CAopt, respectively. The mean monitor units for CA0, CA70 and CAopt were 635 ± 107 MU, 597 ± 96 MU and 587 ± 104 MU, respectively. The mean peripheral dose was significantly increased with CA70 against CA0 (p value < 0.001) despite reduced monitor units. Collimator optimization resulted in reduction in monitor units and peripheral dose. The number of monitor units are reduced with the rotational collimator approach, which results in reduced delivery time. However, we conclude that peripheral dose should be analyzed when assessing monitor unit differences in IMRT plans.

Keywords

Inverse planningIMRTcollimator rotationcollimator optimization
Type
Original Article
Information
Journal of Radiotherapy in Practice , Volume 11 , Issue 2 , June 2012 , pp. 107 - 115
Copyright
Copyright © Cambridge University Press 2012

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References

Ezzell, GA, Galvin, JM, Low, D et al.; IMRT subcommitte; AAPM Radiation Therapy committee. Guidance document on delivery, treatment planning, and clinical implementation of IMRT: report of the IMRT Subcommittee of the AAPM Radiation Therapy Committee. Med Phys 2003; 30:2089–2115.CrossRefGoogle Scholar
Jeraj, M, Robar, V. Multileaf collimator in Radiotherapy. Radiation Oncology 2004; 38(3): 235–240.Google Scholar
Pugachev, AB, Boyer, AL, Xing, L. Beam orientation optimization in intensity-modulated radiation treatment planning. Med Phys 2000; 27:1238–1245.CrossRefGoogle ScholarPubMed
Boyer, A, Biggs, P, Galvin, J et al. Basic application of multileaf collimators”, American Association of Physicists in Medicine (AAPM). Med Phys 2001; Report no 72.Google Scholar
Milette, MP, Otto, K. Maximizing the potential of direct aperture optimization through collimator rotation. Med Phys 2007; 34:1431–1438.CrossRefGoogle ScholarPubMed
Otto, K, Clark, BG. Enhancement of IMRT delivery through MLC rotation. Phys Med Biol 2002; 47:3997–4017.CrossRefGoogle ScholarPubMed
Brahme, A. Optimal setting of multileaf collimators in stationary beam radiation therapy. Strahlenther Onkol 1988; 164:343–350.Google ScholarPubMed
Fung, AY, Enke, CA, Ayyangar, KM et al. Effects of field parameters on IMRT plan quality for gynecological cancer: a case study. J Appl Clin Med Phys 2005; 6:46–62.CrossRefGoogle ScholarPubMed
Otto, K. Volumetric modulated arc therapy: IMRT in a single gantry arc. Med Phys 2008; 35:310–317.CrossRefGoogle Scholar
Khoo, VS, Dearnaley, DP. Question of dose, fractionation and technique: ingredients for testing hypofractionation in prostate cancer–the CHHiP trial. Clin Oncol (R Coll Radiol) 2008; 20:12–14.CrossRefGoogle ScholarPubMed
Pengpeng, Z, Laura, H, Yingli, Y, Yoshiya, Y, Gig, M, Margie, H. Optimization of collimator trajectory in volumetric modulated arc therapy: Development and evaluation for paraspinal SBRT. Int J Radiation Oncology Biol Phys 2010; 77(2): 591–599.Google Scholar
Boylan, CJ, Golby, C, Rowbottom, CG. A VMAT planning solution for prostate patients using a commercial treatment planning system. Phys Med Biol 2010; 55:N395–N404.CrossRefGoogle ScholarPubMed
Verbakel, WF, Cuijpers, JP, Hoffmans, D et al. Volumetric intensity-modulated arc therapy vs. conventional IMRT in head-and-neck cancer: a comparative planning and dosimetric study. Int J Radiat Oncol Biol Phys 2009; 74:252–259.CrossRefGoogle ScholarPubMed
Bedford, JL. Treatment planning for volumetric modulated arc therapy. Med Phys 2009; 36:5128–5138.CrossRefGoogle ScholarPubMed
Oliver, M, Ansbacher, W, Beckham, WA. Comparing planning time, delivery time and plan quality for IMRT, RapidArc and Tomotherapy. J Appl Clin Med Phys 2009; 10:3068.CrossRefGoogle ScholarPubMed
Kry, SF, Salehpour, M, Followill, DS et al. The calculated risk of fatal secondary malignancies from intensity-modulated radiation therapy. Int J Radiat Oncol Biol Phys 2005; 62:1195–1203.CrossRefGoogle ScholarPubMed
Hall, EJ, Wuu, CS. Radiation-induced second cancers: the impact of 3D-CRT and IMRT. Int J Radiat Oncol Biol Phys 2003; 56:83–88.CrossRefGoogle ScholarPubMed
Thomas, SJ, Vinall, A, Poynter, A, Routsis, D. A multicentre timing study of intensity-modulated radiotherapy planning and delivery. Clin Oncol (R Coll Radiol) 2010; 22:658–665.CrossRefGoogle ScholarPubMed
Stern, RL. Peripheral dose from a linear accelerator equipped with multileaf collimation. Med Phys 1999; 26:559–563.CrossRefGoogle ScholarPubMed