An intraoperative motor tract positioning method in brain tumor surgery: technical note.

Intraoperative 3D recognition of the motor tract is indispensable to avoiding neural fiber injury in brain tumor surgery. However, precise localization of the tracts is sometimes difficult with conventional mapping methods. Thus, the authors developed a novel brain mapping method that enables the 3D recognition of the motor tract for intrinsic brain tumor surgeries. This technique was performed in 40 consecutive patients with gliomas adjacent to motor tracts that have a risk of intraoperative pyramidal tract damage. Motor tracts were electrically stimulated and identified by a handheld brain-mapping probe, the NY Tract Finder (NYTF). Sixteen-gauge plastic tubes were mounted onto the NYTF and inserted in the estimated direction of the motor tract with reference to navigational information. Only the NYTF was removed, leaving the plastic tubes in their places, immediately after muscle motor evoked potentials were recorded at the minimum stimulation current. Motor tracts were electrically identified in all cases. Three-dimensional information on the position of motor tracts was given by plastic tubes that were neurophysiologically placed. Tips of tubes showed the resection limit during tumor removal. Safe tumor resection with an arbitrary safety margin can be performed by adjusting the length of the plastic tubes. The motor tract positioning method enabled the 3D recognition of the motor tract by surgeons and provided for safe resection of tumors. Tumor resections were performed safely before damaging motor tracts, without any postoperative neurological deterioration.

The effect of glucagon on FDG uptake in skeletal muscle.

Glucagon is used as an anti-motility agent during gastrointestinal tract examinations. We experienced subjects with enhanced 18F-fluorodeoxyglucose (FDG) uptake in whole-body skeletal muscle when conducting positron emission tomography (PET). The subjects had been administered glucagon during gastroscopy just prior to PET. This observation prompted us to perform the present retrospective study to determine whether or not glucagon enhances FDG uptake in skeletal muscle. We randomly selected 30 cases, including subjects who had undergone PET and gastroscopy on the same day as cancer screening procedures, and classified them into three groups. In the NO group (n = 10), no medications were used prior to PET. In the SC group (n = 10), scopolamine butylbromide (10 mg) was intravenously administered during endoscopy. In the GL group (n = 10), glucagon (0.5 mg) was intravenously administered during endoscopy. Both drugs were administered 45-60 min prior to FDG administration. The mean standardized uptake value (SUV) for gluteal muscle was 0.7 ± 0.14, 0.69 ± 0.15, and 0.99 ± 0.7 in the NO, SC, and GL groups, respectively. The SUV in the GL group was highest, but the difference was not statistically significant. In the subject with the highest SUV (3.04; GL group), the quality of the oncologic PET image was impaired, perhaps because of a relative decrease of FDG distribution in the chest and abdomen. Because previous literature showed that via hyperglycemia and hyperinsulinemia glucagon has the effect of increasing FDG uptake in skeletal muscle, the use of glucagon should be avoided just prior to FDG PET, although in our subjects, no statistical proof that glucagon enhances FDG uptake in skeletal muscle was obtained.

Radio-guided brain tumorectomy using a gamma detecting probe and a mobile solid-state gamma camera.

BACKGROUND: We herein report a technique to distinguish brain tumors from normal brain tissue during surgery using a gamma probe and a solid-state mobile gamma camera after (99m)Tc-hexakis-2-methoxy-isobutyl-isonitrile ((99m)Tc-MIBI) is administered to patients immediately before operation. METHODS: We examined 13 patients with brain tumors. Before the operation, (99m)Tc-MIBI single photon emission computed tomography (SPECT) was performed to assess accumulation in the tumors. On the day of the operation, (99m)Tc-MIBI was administered intravenously and craniotomy for tumor resection was performed. During the operation, the tumor was localized with a gamma probe and preremoval scintigraphy images were taken with a mobile gamma camera. After tumor resection was completed, residual tumors were confirmed using it again. We compared accumulation found in the preoperative SPECT images and intraoperative scintigraphy images, performed a histologic examination of adjacent tissues, and measured the dose the personnel was exposed to per operation. RESULTS: In all patients, tumors were confirmed by a gamma probe and scintigraphy during the operation. Intraoperative accumulation in tumors was significantly related to accumulation found in the preoperative (99m)Tc-MIBI SPECT images. In 9 out of 13 patients, accumulation disappeared in the postremoval scintigraphy images, and no tumor tissue was found by histologic examination. Residual tumor tissue was found in 4 patients. Average exposure of the personnel per operation was 22.9 +/- 4.0 microSv. CONCLUSION: Resection of brain tumors with a gamma probe and a mobile gamma camera was very useful since the area to be removed was easily identified and residual tumors could be detected.

Chronic subdural hematoma following dural metastasis of gastric cancer: measurement of pre- and postoperative cerebral blood flow with N-isopropyl-p-[123I]iodoamphetamine--case report.

A 58-year-old female with gastric cancer presented with left chronic subdural hematoma (CSH) without history of head injury. Magnetic resonance imaging revealed left CSH with atypical findings such as abnormal dural enhancement and swelling of the left cerebral hemisphere. One month after gastrectomy, motor aphasia and right hemiparesis developed. Irrigation of the left CSH was performed. The hematoma was abnormally mucinous and became solid immediately after irrigation. Histological examination showed that adenocarcinoma cells had metastasized to the dura mater and the outer membrane of the hematoma. The preoperative cerebral blood flow (CBF) in the affected cerebral hemisphere, measured by single photon emission computed tomography using N-isopropyl-p-[123I]iodoamphetamine, was much higher than that in the opposite hemisphere, whereas the postoperative CBF was almost equal in both hemispheres. Subdural hematomas secondary to dural metastases of extraneuronal malignancies are rare, and are usually the chronic type. Measurement of the pre- and postoperative CBF in the present patient with CSH following dural metastasis of the malignant tumor showed that preoperative hyperemia in the affected hemisphere may result from dilation of the cerebral vessels caused by the effects of the CSH.