Failure rate of contemporary low-dose radiosurgical technique for vestibular schwannoma

Clinical article

Bruce E. Pollock, Michael J. Link, Robert L. Foote

Research output: Contribution to journalArticle

34 Citations (Scopus)

Abstract

Object. The decline in cranial nerve morbidity after radiosurgery for vestibular schwannoma (VS) correlates with dose reduction and other technical changes to this procedure. The effect these changes have had on tumor control has not been well documented. Methods. The authors performed a retrospective review of 293 patients with VSs who underwent radiosurgery between 1990 and 2004 and had a minimum of 24 months of imaging follow-up (90% of the entire series). The median radiation dose to the tumor margin was 13 Gy. Treatment failure was defined as progressive tumor enlargement noted on 2 or more imaging studies. The mean postradiosurgical follow-up was 60.9 ± 32.5 months. Results. Tumor growth was noted in 15 patients (5%) at a median of 32 months after radiosurgery. Radiographically demonstrated tumor control was 96% at 3 years and 94% at 7 years after radiosurgery. Univariate analysis revealed 2 factors that correlated with failed radiosurgery for VS: an increasing number of isocenters (p = 0.03) and tumor margin radiation doses ≤ 13 Gy (p = 0.02). Multivariate analysis showed that only an increasing number of isocenters correlated with failed VS radiosurgery (hazard ratio 1.1, 95% CI 1.02-1.32, p < 0.05). The tumor margin radiation dose (p = 0.22) was not associated with tumor growth after radiosurgery. Conclusions. Distortion of stereotactic MR imaging coupled with increased radiosurgical conformality and progressive dose reduction likely caused some VSs to receive less than the prescribed radiation dose to the entire tumor volume.

Original languageEnglish (US)
Pages (from-to)840-844
Number of pages5
JournalJournal of Neurosurgery
Volume111
Issue number4
DOIs
StatePublished - 2009

Fingerprint

Acoustic Neuroma
Radiosurgery
Neoplasms
Radiation
Cranial Nerves
Growth
Tumor Burden
Treatment Failure
Multivariate Analysis
Morbidity

Keywords

  • Acoustic neuroma
  • Dosimetry
  • Radiosurgery
  • Vestibular schwannoma

ASJC Scopus subject areas

  • Clinical Neurology
  • Surgery

Cite this

Failure rate of contemporary low-dose radiosurgical technique for vestibular schwannoma : Clinical article. / Pollock, Bruce E.; Link, Michael J.; Foote, Robert L.

In: Journal of Neurosurgery, Vol. 111, No. 4, 2009, p. 840-844.

Research output: Contribution to journalArticle

Pollock, Bruce E. ; Link, Michael J. ; Foote, Robert L. / Failure rate of contemporary low-dose radiosurgical technique for vestibular schwannoma : Clinical article. In: Journal of Neurosurgery. 2009 ; Vol. 111, No. 4. pp. 840-844.
@article{e53e7303e73247cca09566ad834806ac,
title = "Failure rate of contemporary low-dose radiosurgical technique for vestibular schwannoma: Clinical article",
abstract = "Object. The decline in cranial nerve morbidity after radiosurgery for vestibular schwannoma (VS) correlates with dose reduction and other technical changes to this procedure. The effect these changes have had on tumor control has not been well documented. Methods. The authors performed a retrospective review of 293 patients with VSs who underwent radiosurgery between 1990 and 2004 and had a minimum of 24 months of imaging follow-up (90{\%} of the entire series). The median radiation dose to the tumor margin was 13 Gy. Treatment failure was defined as progressive tumor enlargement noted on 2 or more imaging studies. The mean postradiosurgical follow-up was 60.9 ± 32.5 months. Results. Tumor growth was noted in 15 patients (5{\%}) at a median of 32 months after radiosurgery. Radiographically demonstrated tumor control was 96{\%} at 3 years and 94{\%} at 7 years after radiosurgery. Univariate analysis revealed 2 factors that correlated with failed radiosurgery for VS: an increasing number of isocenters (p = 0.03) and tumor margin radiation doses ≤ 13 Gy (p = 0.02). Multivariate analysis showed that only an increasing number of isocenters correlated with failed VS radiosurgery (hazard ratio 1.1, 95{\%} CI 1.02-1.32, p < 0.05). The tumor margin radiation dose (p = 0.22) was not associated with tumor growth after radiosurgery. Conclusions. Distortion of stereotactic MR imaging coupled with increased radiosurgical conformality and progressive dose reduction likely caused some VSs to receive less than the prescribed radiation dose to the entire tumor volume.",
keywords = "Acoustic neuroma, Dosimetry, Radiosurgery, Vestibular schwannoma",
author = "Pollock, {Bruce E.} and Link, {Michael J.} and Foote, {Robert L.}",
year = "2009",
doi = "10.3171/2009.3.JNS08949",
language = "English (US)",
volume = "111",
pages = "840--844",
journal = "Journal of Neurosurgery",
issn = "0022-3085",
publisher = "American Association of Neurological Surgeons",
number = "4",

}

TY - JOUR

T1 - Failure rate of contemporary low-dose radiosurgical technique for vestibular schwannoma

T2 - Clinical article

AU - Pollock, Bruce E.

AU - Link, Michael J.

AU - Foote, Robert L.

PY - 2009

Y1 - 2009

N2 - Object. The decline in cranial nerve morbidity after radiosurgery for vestibular schwannoma (VS) correlates with dose reduction and other technical changes to this procedure. The effect these changes have had on tumor control has not been well documented. Methods. The authors performed a retrospective review of 293 patients with VSs who underwent radiosurgery between 1990 and 2004 and had a minimum of 24 months of imaging follow-up (90% of the entire series). The median radiation dose to the tumor margin was 13 Gy. Treatment failure was defined as progressive tumor enlargement noted on 2 or more imaging studies. The mean postradiosurgical follow-up was 60.9 ± 32.5 months. Results. Tumor growth was noted in 15 patients (5%) at a median of 32 months after radiosurgery. Radiographically demonstrated tumor control was 96% at 3 years and 94% at 7 years after radiosurgery. Univariate analysis revealed 2 factors that correlated with failed radiosurgery for VS: an increasing number of isocenters (p = 0.03) and tumor margin radiation doses ≤ 13 Gy (p = 0.02). Multivariate analysis showed that only an increasing number of isocenters correlated with failed VS radiosurgery (hazard ratio 1.1, 95% CI 1.02-1.32, p < 0.05). The tumor margin radiation dose (p = 0.22) was not associated with tumor growth after radiosurgery. Conclusions. Distortion of stereotactic MR imaging coupled with increased radiosurgical conformality and progressive dose reduction likely caused some VSs to receive less than the prescribed radiation dose to the entire tumor volume.

AB - Object. The decline in cranial nerve morbidity after radiosurgery for vestibular schwannoma (VS) correlates with dose reduction and other technical changes to this procedure. The effect these changes have had on tumor control has not been well documented. Methods. The authors performed a retrospective review of 293 patients with VSs who underwent radiosurgery between 1990 and 2004 and had a minimum of 24 months of imaging follow-up (90% of the entire series). The median radiation dose to the tumor margin was 13 Gy. Treatment failure was defined as progressive tumor enlargement noted on 2 or more imaging studies. The mean postradiosurgical follow-up was 60.9 ± 32.5 months. Results. Tumor growth was noted in 15 patients (5%) at a median of 32 months after radiosurgery. Radiographically demonstrated tumor control was 96% at 3 years and 94% at 7 years after radiosurgery. Univariate analysis revealed 2 factors that correlated with failed radiosurgery for VS: an increasing number of isocenters (p = 0.03) and tumor margin radiation doses ≤ 13 Gy (p = 0.02). Multivariate analysis showed that only an increasing number of isocenters correlated with failed VS radiosurgery (hazard ratio 1.1, 95% CI 1.02-1.32, p < 0.05). The tumor margin radiation dose (p = 0.22) was not associated with tumor growth after radiosurgery. Conclusions. Distortion of stereotactic MR imaging coupled with increased radiosurgical conformality and progressive dose reduction likely caused some VSs to receive less than the prescribed radiation dose to the entire tumor volume.

KW - Acoustic neuroma

KW - Dosimetry

KW - Radiosurgery

KW - Vestibular schwannoma

UR - http://www.scopus.com/inward/record.url?scp=70349925729&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=70349925729&partnerID=8YFLogxK

U2 - 10.3171/2009.3.JNS08949

DO - 10.3171/2009.3.JNS08949

M3 - Article

VL - 111

SP - 840

EP - 844

JO - Journal of Neurosurgery

JF - Journal of Neurosurgery

SN - 0022-3085

IS - 4

ER -