Assessment of imaging studies used with radiosurgery: a volumetric algorithm and an estimation of its error

Technical note

John W. Snell Ph.D.1, Jason Sheehan M.D., Ph.D.1, Matei Stroila Ph.D.1, and Ladislau Steiner M.D., Ph.D.1
View More View Less
  • 1 Lars Leksell Gamma Knife Center, Department of Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia
Restricted access

Purchase Now

USD  $45.00

JNS + Pediatrics - 1 year subscription bundle (Individuals Only)

USD  $515.00

JNS + Pediatrics + Spine - 1 year subscription bundle (Individuals Only)

USD  $612.00
Print or Print + Online

✓ The Gamma Knife has played an increasingly important role in the neurosurgical treatment of patients. Intracranial lesions are not removed by radiosurgery. Rather, the goal of treatment is to induce tumor control. During planning, the creation of dose–volume histograms requires an accurate volumetric analysis of intracranial lesions selected for radiosurgery. In addition, an accurate follow-up imaging analysis of tumor volume is essential for assessing the results of radiosurgery. Nevertheless, sources of volumetric error and their expected magnitudes must be properly understood so that the operator may correctly interpret apparent changes in tumor volume. In this paper, the authors examine the often-neglected contributions of imaging geometry (principally image slice thickness and separation) to overall volumetric error.

One of the fundamental sources of volumetric error is that resulting from the geometry of the acquisition protocol. The authors consider the image sampling geometry of tomographic modalities and its contribution to volumetric error through a simulation framework in which a synthetic digital tumor is taken as the primary model. Because the exact volume of the digital phantom can be computed, the volume estimates derived from tomographic “slicing” can be directly compared precisely and independently from other error sources. In addition to providing empirical bounds on volumetric error, this approach provides a tool for guiding the specification of imaging protocols when a specific volumetric accuracy, or volume change sensitivity, for particular structures is sought a priori.

Using computational geometry techniques, the volumetric error associated with image acquisition geometry was shown to be dependent on the number of slices through the region of interest (ROI) and the lesion volume. With a minimum of five slices through the ROI, the volume of a compact lesion could be calculated accurately with less than 10% error, which was the predetermined goal for the purposes of computing accurate dose–volume histograms and determining follow-up changes in tumor volume.

Accurate dose–volume histograms can be generated and follow-up volumetric assessments performed, assuming accurate lesion delineation, when the object is visualized on at least five axial slices. Volumetric analysis based on fewer than five slices yields unacceptably larger errors (that is, > 10%). These volumetric findings are particularly relevant for radiosurgical treatment planning and follow-up analysis. Through the application of this volumetric methodology and a greater understanding of the error associated with it, neurosurgeons can better perform radiosurgery and assess its outcome.

Abbreviations used in this paper:

CT = computerized tomography; MR = magnetic resonance; ROI = region of interest; SD = standard deviation; 3D = three-dimensional.

JNS + Pediatrics - 1 year subscription bundle (Individuals Only)

USD  $515.00

JNS + Pediatrics + Spine - 1 year subscription bundle (Individuals Only)

USD  $612.00
  • 1

    Arvo J: Graphics Gems II San Diego, CA, Academic Press, 1991

  • 2

    Bevington PR: Data Reduction and Error Analysis for the Physical Sciences New York, McGraw-Hill, 1969

  • 3

    Brassow F, , Spielmann RP, & Herberhold C: Computertomographische Volumetrie des pneumatischen Systems des Ohres. Ein Vergleich zwischen Normalkollektiv und Patienten mit Ohrerkrankungen. ROFO Fortschr Geb Rontgenstr Nuklearmed 140:158161, 1984

    • Search Google Scholar
    • Export Citation
  • 4

    Cernica G, , de Boer SF, , Diaz A, , Fenstermaker RA, & Podgorsak MB: Dosimetric accuracy of a staged radiosurgery treatment. Phys Med Biol 50:19912002, 2005

    • Search Google Scholar
    • Export Citation
  • 5

    Georgi P, , Strauss L, , Sturm V, , Osterag H, , Sinn H, & Rommel T: Pra- und intraoperative volumenbestimmung bei Craniopharyngiomcysten. Nuklearmedizin 19:187190, 1980

    • Search Google Scholar
    • Export Citation
  • 6

    Goodman JE, & O’Rourke J: Handbook of Discrete and Computational Geometry Boca Raton, FL, CRC Press, 1997

  • 7

    Igarashi M, , O-Uchi T, , Isago H, & Wright WK: Utricular and saccular volumetry in human temporal bones. Acta Otolaryngol 95:7580, 1983

  • 8

    Kondziolka D, , Nathoo N, , Flickinger JC, , Niranjan A, , Maitz AH, & Lunsford LD: Long-term results after radiosurgery for benign intracranial tumors. Neurosurgery 53:815822, 2003

    • Search Google Scholar
    • Export Citation
  • 9

    Kuo JS, , Chen JC, , Yu C, , Zelman V, , Giannotta SL, & Petrovich Z, et al.: Gamma knife radiosurgery for benign cavernous sinus tumors: quantitative analysis of treatment outcomes. Neurosurgery 54:13851394, 2004

    • Search Google Scholar
    • Export Citation
  • 10

    Lim M, , Gibbs IC, , Adler JR Jr, , Martin DP, & Chang SD: The efficacy of linear accelerator stereotactic radiosurgery in treating glomus jugulare tumors. Technol Cancer Res Treat 2:261265, 2003

    • Search Google Scholar
    • Export Citation
  • 11

    Linskey ME, , Lunsford LD, & Flickinger JC: Neuroimaging of acoustic nerve sheath tumors after stereotaxic radiosurgery. AJNR Am J Neuroradiol 12:11651175, 1991

    • Search Google Scholar
    • Export Citation
  • 12

    Linskey ME, , Lunsford LD, & Flickinger JC: Tumor control after stereotactic radiosurgery in neurofibromatosis patients with bilateral acoustic tumors. Neurosurgery 31:829839, 1992

    • Search Google Scholar
    • Export Citation
  • 13

    Losa M, , Valle M, , Mortini P, , Franzin A, , da Passano CF, & Cenzato M, et al.: Gamma knife surgery for treatment of residual nonfunctioning pituitary adenomas after surgical debulking. J Neurosurg 100:438444, 2004

    • Search Google Scholar
    • Export Citation
  • 14

    Mizrahi A, & Sullivan M: Calculus and Analytic Geometry Belmont, CA, Wadsworth, 1982

  • 15

    Noren G, , Greitz D, , Hirsch A, & Lax I: Gamma knife surgery in acoustic tumors. Acta Neurochir Suppl (Wien) 58:104107, 1993

  • 16

    Orthner H, & Seler W: Planimetrische Volumetrie an menschlichen Gehirnen. Fortschr Neurol Psychiatr Grenzgeb 43:191209, 1975

  • 17

    Pollock BE, & Carpenter PC: Stereotactic radiosurgery as an alternative to fractionated radiotherapy for patients with recurrent or residual nonfunctioning pituitary adenomas. Neurosurgery 53:10861094, 2003

    • Search Google Scholar
    • Export Citation
  • 18

    Sheehan JP, , Sun MH, , Kondziolka D, , Flickinger J, & Lunsford LD: Radiosurgery for non–small cell lung carcinoma metastatic to the brain: long-term outcomes and prognostic factors influencing patient survival time and local tumor control. J Neurosurg 97:12761281, 2002

    • Search Google Scholar
    • Export Citation
  • 19

    Shirley P, & Tuchman AA: Polygonal approximation to direct scalar volume rendering. Proceedings San Diego Workshop on Volume Visualization Computer Graphics 24:6370, 1990

    • Search Google Scholar
    • Export Citation
  • 20

    Steiner L, , Bergvall U, & Zwetnow N: Quantitative estimation of intracerebral and intraventricular hematoma by computer tomography. Acta Radiol Suppl 346:143154, 1975

    • Search Google Scholar
    • Export Citation
  • 21

    Stepanek V, & Zavada M: Prakticke vyuziti rentgenove plicni voluminometrie, planimetrie a koeficientu roztazlivosti hrudniku. Cesk Radiol 23:224230, 1969

    • Search Google Scholar
    • Export Citation

Metrics

All Time Past Year Past 30 Days
Abstract Views 571 88 10
Full Text Views 162 4 0
PDF Downloads 116 3 0
EPUB Downloads 0 0 0