Hostname: page-component-8448b6f56d-sxzjt Total loading time: 0 Render date: 2024-04-25T05:26:33.463Z Has data issue: false hasContentIssue false
  • English
  • Français

Megavoltage versus kilovoltage image guidance for efficiency and accuracy in head and neck IMRT

Published online by Cambridge University Press:  01 December 2009

D. Willis ,
C. Fox ,
A. Haworth ,
A. Rolfo ,
A. Herschtal  and
T. Kron
D. Willis
Affiliation:
1Division of Radiation Oncology
C. Fox
Affiliation:
1Division of Radiation Oncology
A. Haworth
Affiliation:
1Division of Radiation Oncology
A. Rolfo
Affiliation:
1Division of Radiation Oncology
A. Herschtal
Affiliation:
2Biostatistics and Clinical Trials, Peter MacCallum Cancer Centre, St. Andrews Place, Melbourne, Victoria 3002, Australia
T. Kron
Affiliation:
1Division of Radiation Oncology
Get access Rights & Permissions [Opens in a new window]

Abstract

Accurate patient positioning is vitally important in intensity modulated radiation therapy (IMRT) for head and neck (H&N) cancer. The introduction of kilovoltage (kV) on-board imaging (OBI) at our centre was anticipated to improve the accuracy and efficiency of H&N IMRT patient position verification over traditional megavoltage (MV) electronic portal imaging (EPI). This study compares these imaging systems with a phantom accuracy study and retrospective analysis of imaging workload in H&N IMRT at our centre. Six therapists performed online evaluation of phantom images, and residual positional errors for each system were recorded. The largest residual error was 1 mm for OBI and 3 mm for EPI. The estimated improvement in residual error in OBI over EPI was 0.57 mm (95% confidence interval 0.33–0.81 mm), suggesting treatment staff would be better able to detect set-up deviations with OBI. Electronic treatment records of 20 H&N IMRT patients (10 verified daily with MV EPI and 10 with kV OBI) were analysed. Mean imaging session duration was 9.51 min for EPI and 9.76 min for OBI. Analysis found no evidence of an effect on duration due to the imaging system used for this subset of patients (p = 0.664).

Keywords

Head and neckIMRTkV verification imagingradiation therapy
Type
Original Article
Information
Journal of Radiotherapy in Practice , Volume 8 , Issue 4 , December 2009 , pp. 177 - 184
Copyright
Copyright © Cambridge University Press 2009

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Tome, WA, Fowler, JF. On cold spots in tumor subvolumes. Med Phys 2002; 29: 1590–1598.CrossRefGoogle ScholarPubMed
Manning, MA, Wu, Q, Cardinale, RM, Mohan, R, Lauve, AD, Kavanagh, BD, Morris, MM, Schmidt-Ullrich, RK. The effect of setup uncertainty on normal tissue sparing with IMRT for head-and-neck cancer. Int J Radiat Oncol Biol Phys 2001; 51: 1400–1409.CrossRefGoogle ScholarPubMed
Pisani, L, Lockman, D, Jaffray, D, Yan, D, Martinez, A, Wong, J. Setup error in radiotherapy: on-line correction using electronic kilovoltage and megavoltage radiographs. Int J Radiat Oncol Biol Phys 2000; 47: 825–839.CrossRefGoogle ScholarPubMed
Jaffray, DA, Drake, DG, Moreau, M, Martinez, AA, Wong, JW. A radiographic and tomographic imaging system integrated into a medical linear accelerator for localization of bone and soft-tissue targets. Int J Radiat Oncol Biol Phys 1999; 45: 773–789.CrossRefGoogle ScholarPubMed
Fox, TH, Elder, ES, Crocker, IR, Davis, LW, Landry, JC, Johnstone, PA. Clinical implementation and efficiency of kilovoltage image-guided radiation therapy. J Am Coll Radiol 2006; 3: 38–44.CrossRefGoogle ScholarPubMed
Dosoretz, AM, Court, LE, Chen, AB et al. Delineation of lymph node volumes in head and neck IMRT treatment planning: consistency and variability among physicians. Int J Radiat Oncol Biol Phys 2007; 69(1 Suppl): S204.CrossRefGoogle Scholar
Suzuki, M, Nishimura, Y, Nakamatsu, K, Okumura, M, Hashiba, H, Koike, R, Kanamori, S, Shibata, T. Analysis of interfractional set-up errors and intrafractional organ motions during IMRT for head and neck tumors to define an appropriate planning target volume (PTV)- and planning organs at risk volume (PRV)-margins. Radiother Oncol 2006; 78: 283–290.CrossRefGoogle ScholarPubMed
Zhang, L, Garden, AS, Lo, J et al. Multiple regions-of-interest analysis of setup uncertainties for head-and-neck cancer radiotherapy. Int J Radiat Oncol Biol Phys 2006; 64: 1559–1569.CrossRefGoogle ScholarPubMed
Li, H, Zhu, XR, Zhang, L et al. Comparison of 2D radiographic images and 3D cone beam computed tomography for positioning head-and-neck radiotherapy patients. Int J Radiat Oncol Biol Phys 2008; 71: 916–925.CrossRefGoogle ScholarPubMed
Hong, TS, Tomé, WA, Chappell, RJ, Chinnaiyan, P, Mehta, MP, Harari, PM. The impact of daily setup variations on head-and-neck intensity-modulated radiation therapy. Int J Radiat Oncol Biol Phys 2005; 61: 779–788.CrossRefGoogle ScholarPubMed
Court, LE, Wolfsberger, L, Allen, AM, James, S, Tishler, RB. Clinical experience of the importance of daily portal imaging for head and neck IMRT treatments J App Clin Med Phys 2008; 9: 26–33.CrossRefGoogle ScholarPubMed
Herman, MG. Clinical use of electronic portal imaging. Sem Rad Onc 2005; 15: 157–167.CrossRefGoogle ScholarPubMed