Gamma Knife Thalamotomy for Parkinson Disease and Essential Tremor: A Prospective Multicenter Study.

Ohye, Chihiro MD, DMSc; Higuchi, Yoshinori MD, PhD; Shibazaki, Toru MD; Hashimoto, Takao MD, PhD;  

Neurosurgery 70:3:526–536, 2012. doi: 10.1227/NEU.0b013e3182350893

BACKGROUND: No prospective study of gamma knife thalamotomy for intractable tremor has previously been reported.

OBJECTIVE: To clarify the safety and optimally effective conditions for performing unilateral gamma knife (GK) thalamotomy for tremors of Parkinson disease (PD) and essential tremor (ET), a systematic postirradiation 24-month follow-up study was conducted at 6 institutions. We present the results of this multicenter collaborative trial.

METHODS: In total, 72 patients (PD characterized by tremor, n = 59; ET, n = 13) were registered at 6 Japanese institutions. Following our selective thalamotomy procedure, the lateral part of the ventralis intermedius nucleus, 45% of the thalamic length from the anterior tip, was selected as the GK isocenter. A single 130-Gy shot was applied using a 4-mm collimator. Evaluation included neurological examination, magnetic resonance imaging and/or computerized tomography, the unified Parkinson's disease rating scale (UPDRS), electromyography, medication change, and video observations.

RESULTS: Final clinical effects were favorable. Of 53 patients who completed 24 months of follow-up, 43 were evaluated as having excellent or good results (81.1%). UPDRS scores showed tremor improvement (parts II and III). Thalamic lesion size fluctuated but converged to either an almost spherical shape (65.6%), a sphere with streaking (23.4%), or an extended high-signal zone (10.9%). No permanent clinical complications were observed.

CONCLUSION: GK thalamotomy is an alternative treatment for intractable tremors of PD as well as for ET. Less invasive intervention may be beneficial to patients.

Stereotactic Radiosurgery as the Primary Treatment for New and Recurrent Paragangliomas: Is Open Surgical Resection Still the Treatment of Choice?

Stereotactic Radiosurgery as the Primary Treatment for New and Recurrent Paragangliomas: Is Open Surgical Resection Still the Treatment of Choice?

Pineal region Tumor. Update at 2 years follow up.

This is a young man of 26 years  with c/o headache vomiting and blurred vision.

MR imaging showed an enhancing mass in the pineal region and obstructive hydrocephalus.

MR Specrtroscopy revealed alow NAA and high choline.

V.P shunt was placed and he was treated with Gamma Knife.It was a single day treatment as usual and patient was discharged next day.

At 6 months he is back to his normal life style and the Follow up MRI shows 90% resolution of the said tumor. Now at 2 years follow Pt. is fine with consistent resolution.

Resolution at 6 Month.

Resolution at 6 Month.

Further Resolution at one year F.up.

Further Resolution at one year F.up.

Consistent Resolution at 2 years follow up.

Gamma knife Radiosurgery for Glomus Jugulare Tumor.

This 24 years old lady presented with h/o vertigo since 10 years, bilateral tinnitus more on right side since 2 years, headache since one year. She had loss of right gag and palatal reflexes, atrophied tongue on right side with fasciculation and right deviation.

.Patient was treated with marginal dose of 14 Gy with 43% isodose line was prescribed for the target volume 20.3 cc; multiple iso centers with 18, 14 and 8 mm collimators were used in APS and trunnion mode.

Pre Gamma Knife radiosurgery.
Glomus jugulare Tumor.
Volume 20.3 cc.

Follow up CT images Obtained  18 months after GKRS, showing tumor volume 5.2 cm3.

There is remarkable clinical improvement especially in tinnitus and hoarseness.

Gamma Knife Radiosurgery in Low Grade Glioma, decrease in T2 High Signal Volume

This, 35 years old man  has presented with  tonic clonic fits with loss of consciousness and sphincter control since five years, responded well to anti-epileptic medicines for three years. Progression in intensity and frequency of the tonic clonic fits observed in last two years, worst since one month. He also presented weakness of left lower limb since one month.Clinical examination has revealed left lower limb monoparesis grade 4/5.

MRI brain with contrast revealed  non enhancing mass in the right parietal para falcine region over motor strip with high T2 signals.  MR Spectroscopy revealed neoplastic activity within the lesion. He had Gamma Knife Radiosurgery with following prescription.

Target	Location	Prescription	Volume
A	Right parietal Glioma	12 Gy @ 50%	17.4 cm³

Low Grade Glioma: Follow up at 3 months shows about 25 % decrease in T2 high signal volume.
Pt. is clinically in static condition with fits controlled on medicine.

Update on Oligodendroglioma GIII,Initially posted last year.

Oligodendroglioma, Grade III (Recurrent)Before Gamma Knife

This 45 years old Lady had undergone left frontal Craniotomy in November 2009 on diagnosis of left frontoparietal  tumor,. On histopathology it was Anaplastic Oligodendroglioma, WHO grade III. She had tonic clonic fits and right hemiparesis. she had received Radiotherapy to left hemisphere using left lateral and posterior fields on 6Mv X-ray beam.  Total dose of 60 Gy in Multiple fractions of 200 cGy had received until March 1, 2010. Temozolamide as conjoined chemotherapy used for 6 weeks during radiotherapy and 3 cycles after one month of radiotherapy.  

On referral, for She had presented progressive recurrence of right hemiparesis and fits since first week of April 2010. On Clinical examination, she had House Brackmann right facial palsy grade I-II and right hemiplegia. MRI brain with contrast had revealed multiple heterogeneous rim enhancing mass in the left parietal region with significant perilesional edema.  Patient referred us for management with GKSRS. Risk of GKSRS explained. These agreed upon wished to proceed. She had treatment with following prescription.

Target	Location	Prescription	Volume
A	Left parietal Glioma	12.0 Gy @ 50%	33.6 cm³
B	Left parietal Glioma lateral part	12.0 Gy @ 40%	3.5 cm³

Multiple isocenters with 18 & 8 mm collimator used in APS mode. She discharged on tapering doses of Dexamethasone and advised follow up after 3 months.

Follow up at 4 months significant  shrinkage of the tumor mass.

Follow up at 9 months shows further decrease in enhancment.

one and half year follow up:
Same clinical and radiological status as seen in last follow up.

Recurrent Meningeal Hemangiopericytoma, 50% resolution at 8 month follow up.

This 43 years old  gentleman from Gujranwala went through excision of posterior fossa tumor in 2008 along with a VP shunt . He presented with complain of headache, vertigo, and imbalance.

 On referral for Gamma Knife, MRI brain with contrast shows the recurrent multilobulated midline extra axial mass  occupying the supracerebellar cistern, encroaching into quadrigeminal cistern besides bulging into upper 4th ventricle.Mass was compressing upon adjacent faces of occipital lobes and superior vermis / adjacent cerebellum. He was treated with 14 Gy at 50% IDL for a Vol. of 27.8 cc. with multiple isocenters.

At GKRS

 Follow up at 8 months shows about 50% resolution. All his symptoms are improved.



After 8 months.

Meningeal Hemangiopericytoma is a rare and aggressive CNS tumor that exhibits a high incidence of local recurrence and distant metastasis.It arises from Zimmerman pericytes in the capillary wall.Till 2001 only 100 caes were reported.