gms | German Medical Science

56. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e. V. (DGNC)
3èmes journées françaises de Neurochirurgie (SFNC)

Deutsche Gesellschaft für Neurochirurgie e. V.
Société Française de Neurochirurgie

07. bis 11.05.2005, Strasbourg

LINAC-radiosurgery with Round-Collimator-Technique for the treatment of pituitary macroadenoma: a risk analysis

LINAC-Radiochirurgie mit Rundkollimatortechnik zur Behandlung von Makroadenomen der Hypophyse: eine Risikoanalyse

Meeting Abstract

  • corresponding author J. W. Voges - Klinik für Stereotaxie und Funktionelle Neurochirurgie
  • Y. Waerzeggers - Klinik für Stereotaxie und Funktionelle Neurochirurgie
  • M. Kocher - Klinik für Strahlentherapie, Universität Köln
  • M. Hoevels - Klinik für Stereotaxie und Funktionelle Neurochirurgie
  • R.-P. Müller - Klinik für Strahlentherapie, Universität Köln
  • V. Sturm - Klinik für Stereotaxie und Funktionelle Neurochirurgie

Deutsche Gesellschaft für Neurochirurgie. Société Française de Neurochirurgie. 56. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e.V. (DGNC), 3èmes journées françaises de Neurochirurgie (SFNC). Strasbourg, 07.-11.05.2005. Düsseldorf, Köln: German Medical Science; 2005. Doc09.05.-07.04

Die elektronische Version dieses Artikels ist vollständig und ist verfügbar unter: http://www.egms.de/de/meetings/dgnc2005/05dgnc0023.shtml

Veröffentlicht: 4. Mai 2005

© 2005 Voges et al.
Dieser Artikel ist ein Open Access-Artikel und steht unter den Creative Commons Lizenzbedingungen (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.de). Er darf vervielf&aauml;ltigt, verbreitet und &oauml;ffentlich zug&aauml;nglich gemacht werden, vorausgesetzt dass Autor und Quelle genannt werden.


Gliederung

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Objective

To assess the risk for hypothalamo-pituitary dysfunction associated with Linear accelerator (LINAC) based radiosurgery (RS) of pituitary macroadenomas.

Methods

From August 1990 through December 2003, 177 patients with pituitary macroadenoma were treated with LINAC-RS according to a prospective protocol, which prescribed the maximum therapeutic radiation dose to be 20 Gy. Until 1996, treatment planning based solely on computed-tomography (CT)-imaging. Since 1997, magnetic-resonance-imaging (MRI) has been routinely integrated. Patients with a minimum actualized follow-up of 12 months, no radiation exposure and no deficit of pituitary function prior to LINAC-RS were considered for evaluation of the “real” risk analyzing multiple variables in a Cox-regression model.

Results

58 patients (median age: 50.5 yrs) with either nonfunctioning (n=11) or hormone-secreting pituitary macroadenoma (median tumour volume: 2.2 cc) were at risk. The median actualized follow-up time was 53.7 mth (range: 16.2-112 mth). A median single dose of 16.5 Gy (range 10-20 Gy) gained local tumour control in >90% of the cases. Normalization of endocrinopathology was documented in 57.7% of the patients with hormone active adenomas. Within a median time of 43.4 mth, 8/58 pts. (13.8%) presented with new insufficiency of anterior pituitary function. None of the variables treatment planning imaging (CT vs. CT/MRI), surgery prior to LINAC-RS, number of surgical interventions, volume of pituitary exposed to different doses (5-20Gy), maximum radiation dose delivered to the pituitary/hypothalamic region (median: 19.2 Gy, range: 5-46 Gy), diabetes mellitus, and nicotine abuse were significantly associated with radiation-induced pituitary damage. Only the presence of “arterial hypertension” significantly increased the risk for pituitary dysfunction (p=0,028).

Conclusions

LINAC-RS using round collimators and a reduced therapeutic dose was highly effective for local tumour control and normalization of hormone hypersecretion. In this protocol, not the applied radiation dose but a risk factor, which alters vessels in general, hence probably modifying the radiation tolerance of small vessels, determined significantly the occurrence of radiation-induced pituitary dysfunction.