Differences in clinical results after LINAC-based single-dose radiosurgery versus fractionated stereotactic radiotherapy for patients with vestibular schwannomas.
OBJECTIVE
To evaluate the outcomes of patients with vestibular schwannoma (VS) treated with fractionated stereotactic radiotherapy (FSRT) vs. those treated with stereotactic radiosurgery (SRS).


METHODS
This study is based on an analysis of 200 patients with 202 VSs treated with FSRT (n = 172) or SRS (n = 30). Patients with tumor progression and/or progression of clinical symptoms were selected for treatment. In 165 out of 202 VSs (82%), RT was performed as the primary treatment for VS, and for 37 VSs (18%), RT was conducted for tumor progression after neurosurgical intervention. For patients receiving FSRT, a median total dose of 57.6 Gy was prescribed, with a median fractionation of 5 x 1.8 Gy per week. For patients who underwent SRS, a median single dose of 13 Gy was prescribed to the 80% isodose.


RESULTS
FSRT and SRS were well tolerated. Median follow-up time was 75 months. Local control was not statistically different for both groups. The probability of maintaining the pretreatment hearing level after SRS with doses of < or =13 Gy was comparable to that of FSRT. The radiation dose for the SRS group (< or =13 Gy vs. >13 Gy) significantly influenced hearing preservation rates (p = 0.03). In the group of patients treated with SRS doses of < or =13 Gy, cranial nerve toxicity was comparable to that of the FSRT group.


CONCLUSIONS
FSRT and SRS are both safe and effective alternatives for the treatment of VS. Local control rates are comparable in both groups. SRS with doses of < or =13 Gy is a safe alternative to FSRT. While FSRT can be applied safely for the treatment of VSs of all sizes, SRS should be reserved for smaller lesions.
Combs
Stephanie E
SE
Department of Radiation Oncology, University of Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany. Stephanie.Combs@med.uni-heidelberg.de
Welzel
Thomas
T
Schulz-Ertner
Daniela
D
Huber
Peter E
PE
Debus
Jürgen
J
D019583:Dose Fractionation, Radiation; D005154:Facial Nerve / Q000528:radiation effects; D005260:Female; D005500:Follow-Up Studies; D006309:Hearing / Q000528:radiation effects; D006801:Humans; D008297:Male; D009464:Neuroma, Acoustic / Q000473:pathology / Q000601:surgery*; D016634:Radiosurgery / Q000009:adverse effects / Q000379:methods*; D014276:Trigeminal Nerve / Q000528:radiation effects