[Repositioning accuracy of cerebral fractionated stereotactic radiotherapy using CT scanning].

Purpose: To evaluate the accuracy of patient repositioning in fractionated cerebral stereotactic radiotherapy using a Brain Lab stereotactic cranial mask in conjunction with standard dental fixation.

Patients And Methods: Fifty planning and checking CT scans were performed in 25 patients. The check CT scan was performed before or after one of the three sessions of treatment.

Twenty years' experience in the treatment of acoustic neuromas with fractionated radiotherapy: a review of 45 cases.

Purpose: To evaluate very long-term results of fractionated radiotherapy (FRT) of acoustic neuromas (AN).

Methods And Materials: From January 1986 to January 2004, FRT was performed in 45 consecutive patients (46 AN). Indications were as follows: poor general condition contraindicating surgery, hearing preservation in bilateral neuromas, partial resection, nonsurgical recurrence.

[Volume-effect and radiotherapy [II]. Part II: volume-effect and normal tissue].

The first part of our work has focused on the relationship between tumor volume and tumor control. Indeed, it is well known that the importance of irradiated volume could be a main parameter of radiation-induced complications. Numerous mathematical models have described the correlation between the irradiated volume and the risk of adverse effects.

[Volume-effect in radiation therapy part one: volume-effect and tumour].

Volume is an important parameter of radiation therapy. Local control is inversely related to tumor size and the complication rate increases with the importance of the irradiated volume. Although the effect of irradiated volume has been widely reported since the beginning of radiotherapy, it has been less studied than other radiation parameters such as dose, fractionation, or treatment duration.

Nicotinic acetylcholine receptor ligands differently affect cytochrome oxidase in the Honeybee brain.

The objective of this study was to determine if nicotinic receptor antagonists known for their ability to impair memory in the honeybee could induce changes in brain metabolism. We tested the effect of antagonists [hexamethonium, mecamylamine, alpha-bungarotoxin (alpha-BTX)] and agonist (nicotine) brain injections on cytochrome oxidase (CO) histochemistry. Within as little as 30 min following nicotine injection, an increase of the staining was observed in almost all the structures analyzed.