Dose Selection in Stereotactic Radiosurgery

2007 ◽  
pp. 28-42 ◽  
Author(s):  
John C. Flickinger ◽  
Douglas Kondziolka ◽  
Ajay Niranjan ◽  
L. Dade Lunsford
Keyword(s):  
Stereotactic Radiosurgery ◽  
Dose Selection

Dose Selection in Stereotactic Radiosurgery

1999 ◽  
Vol 10 (2) ◽  
pp. 271-280 ◽  
Author(s):  
John C. Flickinger ◽  
Douglas Kondziolka ◽  
L. Dade Lunsford
Keyword(s):  
Stereotactic Radiosurgery ◽  
Dose Selection

Stereotactic radiosurgery for metastatic tumors in the pituitary gland and the cavernous sinus

2006 ◽  
Vol 105 (Supplement) ◽  
pp. 37-42 ◽  
Author(s):  
Yoshimasa Mori ◽  
Tatsuya Kobayashi ◽  
Yuta Shibamoto
Keyword(s):  
Pituitary Gland ◽  
Stereotactic Radiosurgery ◽  
Cavernous Sinus ◽  
Cranial Nerves ◽  
Spatial Relationship ◽  
Visual Disturbance ◽  
Brain Parenchyma ◽  
Dose Selection ◽  
Nasal Cancer ◽  
Radiation Side Effects

ObjectMetastases to the pituitary gland and cavernous sinus occasionally occur. Metastases of this nature are problematic because they are adjacent to eloquent structures such as cranial nerves, including the optic pathways and nerves for extraocular movement and facial sensation. Stereotactic radiosurgery has been reported to be safe and effective for metastases in various sites of brain parenchyma, providing the tumors are not large. Radiosurgery can be performed to treat a precisely defined target, and the risk of radiation side effects on the surrounding structures is reduced. The results of Gamma Knife surgery (GKS) for the treatment of metastases in the pituitary gland and the cavernous sinus are evaluated.MethodsAmong 623 patients with brain metastases treated by GKS, 13 patients (2.1%) had pituitary and/or cavernous metastases. The primary malignancies included lung cancer (five cases), breast cancer (two cases), parotid cancer (two cases), renal cell carcinoma, thyroid cancer, nasal cancer, and gastrointestinal stromal tumor (one case each). The location of the tumors was the pituitary gland (Type 1) in four patients, the cavernous sinus (Type 2) in five patients, and both the cavernous sinus and the sellar region (Type 3) in four patients. The patients' symptoms included dysfunction of the pituitary gland (two patients), visual disturbance (four patients), oculomotor palsy (one patient), abducent palsy (five patients), and trigeminal dysfunction (five patients). A margin dose of 12 to 12.3 Gy was delivered to pituitary metastases. A margin dose of 14.4 to 20 Gy was delivered to cavernous lesions. The dose selection depended on the spatial relationship between tumors and the cranial nerves. Imaging and clinical follow-up data have been obtained in nine of 13 patients for 2 to 12 months (median 4 months) after GKS. Three pituitary and/or cavernous tumors are stable in size, and six tumors have disappeared or decreased in size; full or partial improvement of visual function, extraocular movement, and facial sensation have been achieved in these six patients.Conclusions These preliminary results seem to indicate that GKS is a safe and effective treatment for pituitary and cavernous metastases, as it is effective for parenchymal metastases and promptly improved some patients' symptoms.

Stereotactic radiosurgery for trigeminal neuralgia: a multiinstitutional study using the gamma unit

1996 ◽  
Vol 84 (6) ◽  
pp. 940-945 ◽  
Author(s):  
Douglas Kondziolka ◽  
L. Dade Lunsford ◽  
John C. Flickinger ◽  
Ronald F. Young ◽  
Sandra Vermeulen ◽  
...  
Keyword(s):  
Pain Relief ◽  
Trigeminal Neuralgia ◽  
Stereotactic Radiosurgery ◽  
Good Control ◽  
Dose Selection ◽  
Entry Zone ◽  
Content Type ◽  
Root Entry Zone ◽  
Fine Print

✓ A multiinstitutional study was conducted to evaluate the technique, dose-selection parameters, and results of gamma knife stereotactic radiosurgery in the management of trigeminal neuralgia. Fifty patients at five centers underwent radiosurgery performed with a single 4-mm isocenter targeted at the nerve root entry zone. Thirty-two patients had undergone prior surgery, and the mean number of procedures that had been performed was 2.8 (range 1–7). The target dose of the radiosurgery used in the current study varied from 60 to 90 Gy. The median follow-up period after radiosurgery was 18 months (range 11–36 months). Twenty-nine patients (58%) responded with excellent control (pain free), 18 (36%) obtained good control (50%–90% relief), and three (6%) experienced treatment failure. The median time to pain relief was 1 month (range 1 day–6.7 months). Responses remained consistent for up to 3 years postradiosurgery in all cases except three (6%) in which the patients had pain recurrence at 5, 7, and 10 months. At 2 years, 54% of patients were pain free and 88% had 50% to 100% relief. A maximum radiosurgical dose of 70 Gy or greater was associated with a significantly greater chance of complete pain relief (72% vs. 9%, p = 0.0003). Three patients (6%) developed increased facial paresthesia after radiosurgery, which resolved totally in one case and improved in another. No patient developed other deficits or deafferentation pain. The proximal trigeminal nerve and root entry zone, which is well defined on magnetic resonance imaging, is an appropriate anatomical target for radiosurgery. Radiosurgery using the gamma unit is an additional effective surgical approach for the management of medically or surgically refractory trigeminal neuralgia. A longer-term follow-up review is warranted.

scholarly journals The principles of skull base radiosurgery

2008 ◽  
Vol 24 (5) ◽  
pp. E11 ◽  
Author(s):  
Douglas Kondziolka ◽  
John C. Flickinger ◽  
L. Dade Lunsford
Keyword(s):  
Tumor Growth ◽  
Skull Base ◽  
Stereotactic Radiosurgery ◽  
Cranial Base ◽  
Neurological Function ◽  
Dose Selection ◽  
Analysis Of Results

✓ Stereotactic radiosurgery is commonly used for selected patients with benign cranial base tumors. The goal of radiosurgery is cessation of tumor growth and preservation of neurological function. Over the last 2 decades, the technique of radiosurgery has evolved due to improved imaging, better radiosurgical devices and software, and the continued analysis of results. In this report, the authors discuss technical concepts and dose selection in skull base radiosurgery.

Dose Selection in Stereotactic Radiosurgery

2012 ◽  
pp. 49-57 ◽  
Author(s):  
John C. Flickinger ◽  
Hideyuki Kano ◽  
Ajay Niranjan ◽  
Douglas Kondziolka ◽  
L. Dade Lunsford
Keyword(s):  
Stereotactic Radiosurgery ◽  
Dose Selection
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