CONCLUSION: The preoperative three-dimensional (3D) modeling of the pituitary adenoma together with pituitary gland, optic nerves, carotid arteries, and the sphenoid sinuses was adopted for routine use in our institution for all pituitary surgery patients. It gave the surgeon a more profound orientation to the individual surgical field compared with the use of conventional 2D images only. OBJECTIVE: To demonstrate the feasibility of 3D surgical planning for pituitary adenoma surgery using readily available resources. SUBJECTS AND METHODS: The computed tomography (CT) and magnetic resonance imaging (MRI) data of 40 consecutive patients with pituitary adenoma were used to construct 3D models to be used in preoperative planning and during the surgery. A freely available, open source program (3D Slicer) downloaded to a conventional personal computer (PC) was applied. RESULTS: The authors present a brief description of the 3D reconstruction-based surgical planning workflow. In addition to the preoperative planning the 3D model was used as a 'road map' during the operation. With the 3D model the surgeon was more confident when opening the sellar wall and when evacuating the tumor from areas in contact with vital structures than when using only conventional 2D images.
RATIONALE AND OBJECTIVES: Minimally invasive neurosurgery requires methods to specify surgical boundaries of target tissue, such as brain tumors. This study investigated technical possibilities and clinical usefulness of adapting edema attenuated inversion recovery (EDAIR) pulse sequences to suppress magnetic resonance signal from cerebral edema in brain tumor patients. MATERIALS AND METHODS: A resistive 0.23-T magnetic resonance scanner with magnitude-encoded inversion recovery sequences was used. Twenty-eight separate scanning tests in 25 neurosurgical brain tumor patients were performed on the day before surgery. An inversion recovery sequence with several inversion times between 150 and 2,200 ms was tested. The same sequences were also used intraoperatively and postoperatively. RESULTS: T(1) relaxation time of brain edema varied from case to case. An inversion recovery sequence with an inversion time of 400-800 milliseconds attenuated brain edema and seemed to help in demarcating gross brain tumor for surgical resection. These features were helpful for the evaluation of resectable tumor tissue particularly using neuronavigation techniques. CONCLUSIONS: According to these preliminary findings, inversion recovery sequences supplement other imaging modalities and assist neurosurgeons in evaluating different surgical trajectories and in estimating brain tumor volume before craniotomy.
OBJECTIVES: To assess the long-term survival of brain tumor patients, and in particular to evaluate the relation of quality of life (QOL) to survival among low-grade glioma patients. METHODS: The postoperative survival of 101 brain tumor patients was followed from surgery (1990-1992) until the end of the year 2003. Depression was evaluated by the Beck Depression Inventory (BDI) and QOL with Sintonen's 15D scale before operation and at one year as well as at five years after operation. RESULTS: The mean survival times in years (SD) were significantly related to tumor malignancy, being the shortest, 1.9 (0.6), for patients with high-grade gliomas, while patients with low-grade gliomas or a benign brain tumor had mean survival times of 9.1 (1.0) and 11.6 (0.5), respectively. At all follow-ups, depressed low-grade glioma patients had a significantly shorter survival time, 3.3-5.8 years, compared to non-depressed low-grade glioma patients, 10.0-11.7 years. A decreased level of QOL in low-grade glioma patients was significantly related to the shorter survival. CONCLUSIONS: The results suggest that depression and decreased QOL among low-grade glioma patients is related to shorter survival at long-term follow-up. Decreased QOL may serve as an indicator for poor prognosis in low-grade glioma patients.
OBJECTIVE: To develop a clinically useful method that shows the corresponding planes of intraoperative two-dimensional ultrasonography and intraoperative magnetic resonance imaging (MRI) scans determined with an optical neuronavigator from an intraoperative three-dimensional MRI scan data set, and to determine the qualitative and the quantitative spatial correspondence between the ultrasonography and MRI scans. METHODS: An ultrasound probe was interlinked with an ergonomic and MRI scan-compatible ultrasonography probe tracker to the optical neuronavigator used in a low-field intraoperative MRI scan environment for brain surgery. Spatial correspondence measurements were performed using a custom-made ultrasonography/MRI scan phantom. In this work, instruments to combine intraoperatively collected ultrasonography and MRI scan data with an optical localization method in a magnetic environment were developed. The ultrasonography transducer tracker played an important role. Furthermore, a phantom for ultrasonography and MRI scanning was produced. This is the first report, to our knowledge, regarding the possibility of combining the two most important intraoperative imaging modalities used in neurosurgery, ultrasonography and MRI scanning, to guide brain tumor surgery. RESULTS: The method was feasible and, as shown in an illustrative surgical case, has direct clinical impact on image-guided brain surgery. The spatial deviation between the ultrasonography and the MRI scans was, on average, 1.90 +/- 1.30 mm at depths of 0 to 120 mm from the ultrasonography probe. CONCLUSION: The overall result of this work is a unique method to guide the neurosurgical operation with neuronavigated ultrasonography imaging in an intraoperative MRI scanning environment. The relevance of the method is emphasized in minimally invasive neurosurgery.
OBJECTIVES: To investigate theoretically enhancement and optimal pulse repetition times for Gd-BOPTA and Gd-DTPA enhanced brain imaging at 0.23, 1.5, and 3.0 T. METHODS: The theoretical relaxation times of unenhanced, conventional contrast agent (Gd-DTPA) and new generation contrast agent (Gd-BOPTA) enhanced glioma were calculated. Then, simulation of the signals and contrasts as a function of concentration and pulse repetition time (TR) in spin echo sequence was done at 0.23, 1.5, and 3.0 T. The effect of echo time (TE) on tumor-white matter contrast was also clarified. Three patient cases were imaged at 0.23 T as a test of principle. RESULTS: Gd-BOPTA may give substantially better glioma-to-white matter contrast than Gd-DTPA but is more sensitive to the length of TR. These characteristics are accentuated at 0.23 T. Optimal TR lengths are shorter for Gd-BOPTA than for Gd-DTPA enhanced imaging at all field strengths. TR optimized for Gd-DTPA may thus give suboptimal contrast in Gd-BOPTA enhanced imaging. Higher enhancement with Gd-BOPTA is further accentuated by short TE. CONCLUSION: Appropriate TRs at 0.23 T appear to be approximately 300 to 400 milliseconds and 250 to 300 milliseconds, at 1.5 T 500 to 600 milliseconds and 400 to 450 milliseconds and at 3.0 T 550 to 650 milliseconds and 475 to 525 milliseconds using Gd-DTPA and Gd-BOPTA, respectively. For Gd-BOPTA enhanced imaging, it seems justified to optimize TR according to contrast and seek options like parallel excitation (Hadamard encoding) for increasing the number of slices and SNR.
Prostaglandin E2 has been connected to processes promoting tumor growth in several human malignancies including gliomas. The terminal prostaglandin synthases mPGES-1, mPGES-2, and cPGES convert PGH2 into prostaglandin E2. The inhibition of their function could significantly reduce PGE2 levels in tumors while avoiding some side effects related to the inhibition of the upstream enzymes COX-1 and COX-2. In this study, the immunohistochemical staining of mPGES-1 and, for the first time, the staining of mPGES-2 and cPGES are characterized and compared with COX-1 and COX-2 staining in the same tumor samples of 94 human gliomas. The main results demonstrate over-expression of all three proteins, including cPGES and mPGES-2 that are commonly considered noninducible, in both low- and high-grade tumors. For all three proteins, average expression in tumor cells was higher in grade III tumors than grade II tumors. The analysis showed no correlation between tumor grade and staining of tumor cells or vascular endothelium with any of the antibodies except in oligodendrogliomas where moderate correlation (linear correlation coefficient 0.6; P
The aim of this study was to analyze whether winter birth is related to risk of brain tumor in a clinical sample of patients from northern Finland. The study group comprised 101 patients suffering from a primary brain tumor. When comparing births in winter to births in other seasons, a 1.39-fold (95% CI 1.01-1.77) excess of winter births among patients was observed compared to respective births in the general population (p = 0.026). Especially patients with pituitary adenomas exhibited a 2.5-fold (95% CI 1.5-4.4) excess of winter births. The authors conclude that the season-of-birth effect in brain tumor patients should not be neglected when the actual and important tumorigenesis is investigated.