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50 Functional outcome after radiosurgery for tremor
I. .I. Radiation
172
Oncology
0 Biology
Physics
l
Volume
45, Number
3 Supplement
1999
Results: The actuarial 5-year clinical tumor control rate (no requirement for surgical intervention) for the entire series was 99.4+0.6% with a strict radiographic tumor control rate of 91.0+3.4% (including lmm diameter temporary increases as failures). Five-year actuarial rates of developing facial weakness, facial numbness and decreased Gardner-Robertson hearing level were 1.7+1.0%, 3.4+1.5%, and 20.4+4.0% respectively (Dmin 5 13 Gy: 0%, 3.1%, & 16.6%; Dmin >13 Gy: 3.7%, 3.9%, & 25.4% respectively). Multivariate analyses found that maximum dose best correlated with increasing rates of developing facial weakness (p=O.O16), facial numbness (p = 0.140) and loss of Gardner-Robertson hearing level (p=O.Oll). Tumor diameter did not significantly effect results (p=O.23-0.70). Conclusions: Radiosurgery of acoustic control and lower rates of post-treatment
neuroma using current techniques morbidity compared with earlier
50
AFTER
Hughes
FUNCTIONAL SL’,‘,
OUTCOME
Gollomp
SM2,3, Bednarz
Jefferson Medical College, Wynnewood, PA, USA3
G’,‘,
Philadelphia,
RADIOSURGERY Werner-Wasik
PA, USA’;
Wills
Mr.‘,
is associated reports.
FOR
a continued
high rate of tumor
TREMOR
Curran
Eye Hospital,
with
W.I’,‘,
Goldman
Philadelphia,
HW’,’
PA, USA’;
Lankenau
Hospital,
Objective: To evaluate the clinical outcome for patients treated with radiosurgical ventralis intermedius nucleus (VIM) thalamotomy for tremor. Materials & Methods: All patients treated at Wills Eye Hospital on the Leksell Gamma Knife (r) Unit with radiosurgical VIM thalamotomy to alleviate their tremor were evaluated for functional outcome. Patients were treated for benign tremor (N = 28) or the tremor associated with Parkinson’s disease (N = 6). One patient with Parkinson’s disease had radiosurgical thalamotomy to each side, separated by 13 months. All patients had significant, prolonged symptoms of severe tremor refractory to medical intervention with a 23.year median duration of symptoms (range 5-70 years). The median length of previous medical therapy was 10 years (range 2-45 years). Two patients had previous contralateral open radiofrequency thalamotomy 4 and 12 months prior to radiosurgical thalamotomy. The median patient age was 74 years (range 42-84 years). The median radiation dose delivered through a standard 4-mm secondary collimator helmet was 130 Gy (range 120-140 Gy) prescribed to the 100% isodose line with a single isocenter. The target for lesion location was anatomically positioned with reference to the Schaltenbrand and Wahren Stereotactic Atlas to reflect the VIM. The 50% isodose line was positioned at the junction of the internal capsule and thalamus. MRI-based treatment planning (CT-based for one patient) stereotactically localized all locations. This group of patients was selected for radiosurgical thalamotomy over open radiofrequency thalamotomy because of comorbid medical conditions that limited the open thalamotomy approach. Thirty lesions were created in the left VIM and 5 in the right VIM. Clinical response was measured as a percentage improvement of the preoperative tremor as measured by the neurologist, neurosurgeon, and patient with the Tremor Rating Scale. A “good” clinical response was defined as a decrease in preoperative tremor by 50 to 66% and an “excellent” clinical response was a reduction greater than 66%. Results: Between July 1996 and December 1998, 34 patients were treated with 35 procedures for relief of tremor symptoms. The median follow-up time of these patients is 10 months (range 3-30 months). Twenty-nine patients (85%) had improvement in their handwriting, Thirty patients (88%) had improvement in their ability to groom themselves and to utilize the affected upper extremity for eating. Overall, 8 patients (24%) developed side effects from treatment requiring clinical intervention: three patients experienced edema requiring steroids; one patient developed dysarthria and ataxia; two patients developed mild to moderate ataxia: and two patients developed severe contralateral weakness, dysarthria, and recurrent edema requiring hospitalizations for intravenous steroid administration. Thirty-one patients (89%) experienced either good (23%) or excellent (66%) response of their tremor to this treatment, All of these responses were durable through last follow-up. Two additional patients had responses that stabilized at slightly less than 50% relief relative to pretreatment symptoms. Therefore, 33 patients (94%) had a measurable response to treatment. Conclusions: Gamma Knife”’ radiosurgery for anatomic VIM thalamotomy is an effective technique to treat high surgical risk patients with tremor which has been refractory to multiple medical interventions. To our knowledge, this is the largest published series demonstrating results for benign tremor similar to those obtained with functional mapping and open radiofrequency thalamotomy. The side effect profile for this procedure warrants thoughtful consideration when advising this patient population with debilitating tremors.
5 1
FRACTIONATED LONG TERM
Debus Jr, Wuendrich M’ UniversiQ Hospital
STEREOTACTIC RADIOTHERAPY RESULTS IN 196 PATIENTS M’, Pirzkall
Heidelberg,
A’,
Hoess A*, Schulz-Ertner
Heidelberg,
Germany’;
German
OF LARGE D’; Schlegel Cancer
W’,
Research
SKULL
BASE
Engenhart-Cabillic Center
(dkfz),
MENINGIOMAS: R’, Wannenmacher
Heidelberg,
Germany’
Purpose: Large skull base meningiomas are difficult to treat due to adherent or encompassing critical radiosensitive structures. The role of fractionated stereotactic radiotherapy in the treatment of patients with skull base meningiomas is analyzed. Methods: From 1989 to July 1998 we have treated 196 patients with skull base meningiomas in our institution. The median age was 53 years (range: 10 years-83 years). Histology was obtained in 54% of the patients. The other patients were diagnosed by neuroradiologists on computed tomography and magnetic resonance tomography (46%). Indications for radiotherapy were the onset of new symptoms or a deterioration in neurological condition and radiological documented tumor progression. All patients underwent three-dimensional treatment planning after non-invasive fixation with a precision mask system and stereotactic CT and MRI imaging. Target volume include the macroscopically visible tumor including dural enhancement and a safety distance of 3 mm along the typical anatomical spread of the tumor. Treatment was delivered after virtual simulation on a dedicated stereotactic linear accelerator with 3 to 5 non-coplanar irregular shaped fields by a mid-size multi-leaf-collimator (leaf width 5 mm at isocentre). The median size of the target volume was 52.5 cc (range: 5.2-370 cc). We applied a median dose of 56.8 Gy to the reference point with a daily fraction size of 1.8 Gy. Patients were followed in 6 monthly intervals for the first 2 years and then in yearly intervals with MRI/CT and neurological exam and
172
Oncology
0 Biology
Physics
l
Volume
45, Number
3 Supplement
1999
Results: The actuarial 5-year clinical tumor control rate (no requirement for surgical intervention) for the entire series was 99.4+0.6% with a strict radiographic tumor control rate of 91.0+3.4% (including lmm diameter temporary increases as failures). Five-year actuarial rates of developing facial weakness, facial numbness and decreased Gardner-Robertson hearing level were 1.7+1.0%, 3.4+1.5%, and 20.4+4.0% respectively (Dmin 5 13 Gy: 0%, 3.1%, & 16.6%; Dmin >13 Gy: 3.7%, 3.9%, & 25.4% respectively). Multivariate analyses found that maximum dose best correlated with increasing rates of developing facial weakness (p=O.O16), facial numbness (p = 0.140) and loss of Gardner-Robertson hearing level (p=O.Oll). Tumor diameter did not significantly effect results (p=O.23-0.70). Conclusions: Radiosurgery of acoustic control and lower rates of post-treatment
neuroma using current techniques morbidity compared with earlier
50
AFTER
Hughes
FUNCTIONAL SL’,‘,
OUTCOME
Gollomp
SM2,3, Bednarz
Jefferson Medical College, Wynnewood, PA, USA3
G’,‘,
Philadelphia,
RADIOSURGERY Werner-Wasik
PA, USA’;
Wills
Mr.‘,
is associated reports.
FOR
a continued
high rate of tumor
TREMOR
Curran
Eye Hospital,
with
W.I’,‘,
Goldman
Philadelphia,
HW’,’
PA, USA’;
Lankenau
Hospital,
Objective: To evaluate the clinical outcome for patients treated with radiosurgical ventralis intermedius nucleus (VIM) thalamotomy for tremor. Materials & Methods: All patients treated at Wills Eye Hospital on the Leksell Gamma Knife (r) Unit with radiosurgical VIM thalamotomy to alleviate their tremor were evaluated for functional outcome. Patients were treated for benign tremor (N = 28) or the tremor associated with Parkinson’s disease (N = 6). One patient with Parkinson’s disease had radiosurgical thalamotomy to each side, separated by 13 months. All patients had significant, prolonged symptoms of severe tremor refractory to medical intervention with a 23.year median duration of symptoms (range 5-70 years). The median length of previous medical therapy was 10 years (range 2-45 years). Two patients had previous contralateral open radiofrequency thalamotomy 4 and 12 months prior to radiosurgical thalamotomy. The median patient age was 74 years (range 42-84 years). The median radiation dose delivered through a standard 4-mm secondary collimator helmet was 130 Gy (range 120-140 Gy) prescribed to the 100% isodose line with a single isocenter. The target for lesion location was anatomically positioned with reference to the Schaltenbrand and Wahren Stereotactic Atlas to reflect the VIM. The 50% isodose line was positioned at the junction of the internal capsule and thalamus. MRI-based treatment planning (CT-based for one patient) stereotactically localized all locations. This group of patients was selected for radiosurgical thalamotomy over open radiofrequency thalamotomy because of comorbid medical conditions that limited the open thalamotomy approach. Thirty lesions were created in the left VIM and 5 in the right VIM. Clinical response was measured as a percentage improvement of the preoperative tremor as measured by the neurologist, neurosurgeon, and patient with the Tremor Rating Scale. A “good” clinical response was defined as a decrease in preoperative tremor by 50 to 66% and an “excellent” clinical response was a reduction greater than 66%. Results: Between July 1996 and December 1998, 34 patients were treated with 35 procedures for relief of tremor symptoms. The median follow-up time of these patients is 10 months (range 3-30 months). Twenty-nine patients (85%) had improvement in their handwriting, Thirty patients (88%) had improvement in their ability to groom themselves and to utilize the affected upper extremity for eating. Overall, 8 patients (24%) developed side effects from treatment requiring clinical intervention: three patients experienced edema requiring steroids; one patient developed dysarthria and ataxia; two patients developed mild to moderate ataxia: and two patients developed severe contralateral weakness, dysarthria, and recurrent edema requiring hospitalizations for intravenous steroid administration. Thirty-one patients (89%) experienced either good (23%) or excellent (66%) response of their tremor to this treatment, All of these responses were durable through last follow-up. Two additional patients had responses that stabilized at slightly less than 50% relief relative to pretreatment symptoms. Therefore, 33 patients (94%) had a measurable response to treatment. Conclusions: Gamma Knife”’ radiosurgery for anatomic VIM thalamotomy is an effective technique to treat high surgical risk patients with tremor which has been refractory to multiple medical interventions. To our knowledge, this is the largest published series demonstrating results for benign tremor similar to those obtained with functional mapping and open radiofrequency thalamotomy. The side effect profile for this procedure warrants thoughtful consideration when advising this patient population with debilitating tremors.
5 1
FRACTIONATED LONG TERM
Debus Jr, Wuendrich M’ UniversiQ Hospital
STEREOTACTIC RADIOTHERAPY RESULTS IN 196 PATIENTS M’, Pirzkall
Heidelberg,
A’,
Hoess A*, Schulz-Ertner
Heidelberg,
Germany’;
German
OF LARGE D’; Schlegel Cancer
W’,
Research
SKULL
BASE
Engenhart-Cabillic Center
(dkfz),
MENINGIOMAS: R’, Wannenmacher
Heidelberg,
Germany’
Purpose: Large skull base meningiomas are difficult to treat due to adherent or encompassing critical radiosensitive structures. The role of fractionated stereotactic radiotherapy in the treatment of patients with skull base meningiomas is analyzed. Methods: From 1989 to July 1998 we have treated 196 patients with skull base meningiomas in our institution. The median age was 53 years (range: 10 years-83 years). Histology was obtained in 54% of the patients. The other patients were diagnosed by neuroradiologists on computed tomography and magnetic resonance tomography (46%). Indications for radiotherapy were the onset of new symptoms or a deterioration in neurological condition and radiological documented tumor progression. All patients underwent three-dimensional treatment planning after non-invasive fixation with a precision mask system and stereotactic CT and MRI imaging. Target volume include the macroscopically visible tumor including dural enhancement and a safety distance of 3 mm along the typical anatomical spread of the tumor. Treatment was delivered after virtual simulation on a dedicated stereotactic linear accelerator with 3 to 5 non-coplanar irregular shaped fields by a mid-size multi-leaf-collimator (leaf width 5 mm at isocentre). The median size of the target volume was 52.5 cc (range: 5.2-370 cc). We applied a median dose of 56.8 Gy to the reference point with a daily fraction size of 1.8 Gy. Patients were followed in 6 monthly intervals for the first 2 years and then in yearly intervals with MRI/CT and neurological exam and