[Point of view of the neurosurgeon]

[Medical devices needed for stereotactic radiosurgery and intracranial stereotactic radiotherapy]

Since the previous special issue of Cancer Radiothérapie dedicated to radiosurgery in 1998, many important technological and computer developments have improved external beam radiotherapy treatment device performances. Whereas the Gamma Knife(®) was the gold standard for intracranial radiosurgery, new linear accelerator developments have led to new possibilities for the clinicians. This article describes quickly the different devices available for cranial radiosurgery or fractionated stereotactic radiotherapy.

Microsurgical removal of a petrous apex meningioma after stereotactic radiation: technical case report

OBJECTIVE AND IMPORTANCE

Stereotactic radiation is increasingly advocated as a primary treatment option for benign cranial base lesions. The clinical course of the patient reported herein raises questions regarding the rationale for initiation of radiotherapy to a petrous apex meningioma before microsurgery.

CLINICAL PRESENTATION

We report a 50-year-old woman who experienced medically refractory trigeminal pain. She was diagnosed with a meningioma around the petrous apex and treated by fractionated stereotactic radiation. After a short period of alleviation accompanied by hypesthesia, the pain returned in a previously unknown and violent fashion.

INTERVENTION

Complete tumor removal through a retrosigmoid intradural suprameatal approach resulted in immediate and permanent pain cessation.

CONCLUSION

Radiotherapy should be withheld for benign and accessible tumors of the cranial base until the option of radical microsurgical treatment has been explored.

[Radiosurgery of single brain metastasis without combined total cerebral irradiation. Results of a consecutive series of 12 cases]

PURPOSE

To evaluate the usefulness of radiosurgery without whole brain irradiation for a solitary brain metastasis.

PATIENTS AND METHODS

Between December 1994 and November 1996, 12 patients were treated for a single brain metastasis by radiosurgery alone. Median age was 53, and 10 patients had a Karnofsky performance status above 70. Half the patients had active extracranial disease at the time of radiosurgery. Stereotactic radiosurgery delivered a single dose of 20 Gy (specified at the isocenter with a 70% isodose reference curve). Evaluation of results was performed according to local control, survival, evolution of performance status, as well as evolution of neurologic symptoms.

RESULTS

No patient had immediate toxicity. One month later, ten patients showed improvement in their neurologic impairments, and none had progression of the cerebral lesion according to CT scan evaluation (diminution for seven patients, and stabilization for five). Local control rate was 58%, and median time to failure was 4 months. The overall median survival time was 10 months. Three patients were alive, with good performance status, and six died following cerebral progression.

CONCLUSION

These poor results in terms of local control are in favor of supplementary whole brain irradiation, except for particular cases.