OBJECT: The goal in this study was to evaluate hearing preservation rates and to determine prognostic factors for this outcome following fractionated stereotactic radiotherapy (FSRT) of vestibular schwannoma. METHODS: Thirty-four consecutive patients with serviceable hearing who received FSRT between May 1998 and December 2003 were identified. Clinical and audiometry data were collected prospectively. The prescription dose was 45 Gy in 25 fractions prescribed to the 90% isodose line. The median follow-up duration was 36.5 months (range 12-85 months). The actuarial 2- and 4-year local control rates were 100 and 95.7%, respectively. Permanent trigeminal and facial nerve complications were 0 and 6%, respectively. The actuarial 2- and 3-year serviceable hearing preservation rates were both 63%. The median loss in speech reception threshold was 15 dB (range--10 to 65 dB). The radiotherapy dose to the cochlea was the only significant prognostic factor for hearing deterioration. Radiotherapy dose to the cochlear nucleus, patient age, sex, pre-FSRT hearing grade, tumor volume, and intracanalicular tumor volume failed to show any significance as prognostic factors. RESULTS: Five cases were replanned with four different radiotherapy techniques (namely arcs, dynamic arcs, static conformal fields, and intensity-modulated radiotherapy), with the cochlea defined as an organ at risk. In all cases, replanning resulted in statistically significant reduction in radiation to the cochlea (p = 0.001); however, no single replanning technique was found to be superior. CONCLUSIONS: The radiation dose to the cochlea is strongly predictive for subsequent hearing deterioration. It is essential for the cochlea to be outlined as an organ at risk, and for radiation techniques to be optimized, to improve long-term hearing preservation.
OBJECT: The goal in this study was to evaluate hearing preservation rates and to determine prognostic factors for this outcome following fractionated stereotactic radiotherapy (FSRT) of vestibular schwannoma. METHODS: Thirty-four consecutive patients with serviceable hearing who received FSRT between May 1998 and December 2003 were identified. Clinical and audiometry data were collected prospectively. The prescription dose was 45 Gy in 25 fractions prescribed to the 90% isodose line. The median follow-up duration was 36.5 months (range 12-85 months). The actuarial 2- and 4-year local control rates were 100 and 95.7%, respectively. Permanent trigeminal and facial nerve complications were 0 and 6%, respectively. The actuarial 2- and 3-year serviceable hearing preservation rates were both 63%. The median loss in speech reception threshold was 15 dB (range--10 to 65 dB). The radiotherapy dose to the cochlea was the only significant prognostic factor for hearing deterioration. Radiotherapy dose to the cochlear nucleus, patient age, sex, pre-FSRT hearing grade, tumor volume, and intracanalicular tumor volume failed to show any significance as prognostic factors. RESULTS: Five cases were replanned with four different radiotherapy techniques (namely arcs, dynamic arcs, static conformal fields, and intensity-modulated radiotherapy), with the cochlea defined as an organ at risk. In all cases, replanning resulted in statistically significant reduction in radiation to the cochlea (p = 0.001); however, no single replanning technique was found to be superior. CONCLUSIONS: The radiation dose to the cochlea is strongly predictive for subsequent hearing deterioration. It is essential for the cochlea to be outlined as an organ at risk, and for radiation techniques to be optimized, to improve long-term hearing preservation.
Authors: Kunal S Patel; Edwin Ng; Taranjit Kaur; Tyler Miao; Tania Kaprealian; Percy Lee; Nader Pouratian; Michael T Selch; Antonio A F De Salles; Quinton Gopen; Stephen Tenn; Isaac Yang Journal: J Neurooncol Date: 2019-09-24 Impact factor: 4.130
Authors: Benjamin J Arthurs; Robert K Fairbanks; John J Demakas; Wayne T Lamoreaux; Neil A Giddings; Alexander R Mackay; Barton S Cooke; Ameer L Elaimy; Christopher M Lee Journal: Neurosurg Rev Date: 2011-02-09 Impact factor: 3.042
Authors: Anurag Saraf; Luke R G Pike; Kevin H Franck; Nora K Horick; Beow Y Yeap; Barbara C Fullerton; Irene S Wang; Mohamed E Abazeed; Michael J McKenna; William A Mehan; Scott R Plotkin; Jay S Loeffler; Helen A Shih Journal: Neurosurgery Date: 2022-05-01 Impact factor: 5.315
Authors: Lawrance K Chung; Nolan Ung; John P Sheppard; Thien Nguyen; Carlito Lagman; Winward Choy; Stephen Tenn; Nader Pouratian; Percy Lee; Tania Kaprealian; Michael Selch; Antonio De Salles; Quinton Gopen; Isaac Yang Journal: J Neurol Surg B Skull Base Date: 2017-11-10