Stereotactic irradiation on linear accelerator - ultrasound versus MRI in choroidal melanoma volume calculation.

BACKGROUND: Stereotactic irradiation is one of the treatment modalities for intraocular uveal melanoma. The study's purpose was to describe the background of stereotactic one-day session radiosurgery, how the comparison in the difference between the tumor volume measured values from the magnetic resonance imaging (MRI) method and the ultrasound method was related to it, and which method was more precise to be used for tumor regression after irradiation. METHODS: The group of 147 patients with choroidal melanoma was treated by stereotactic irradiation on the linear accelerator with a single dose of 35.0 Gy. During the standard treatment process the uveal melanoma volumes, needed for dose calculation, were obtained using MRI from the individual stereotactic planning scheme and by ultrasound from the ultrasound device. All volumes were statistically compared using the paired t-test, and for the visualization purpose, the Bland-Altman plot was used. RESULTS: In the group of patients, it was 70 (47.6%) males and 77 (52.4%) females. The tumor volume median was from MRI equal to 0.44 cm3 and from ultrasound equal to 0.53 cm3. The difference between the ultrasound and the MRI volume measured values was statistically significant. However, the Bland-Altman plot clearly documents that the two methods are in agreement and can be used interchangeably. In most of the cases, the measured values of the ultrasound-calculated volume achieved slightly higher measured values. CONCLUSIONS: The calculation of the intraocular uveal tumor volume is a crucial part of the stereotactic irradiation treatment. The ultrasound volume measured values were in most of the cases higher than the measured values from the MRI. Although the methods are comparable and can be used interchangeably, we are recommending using the more precise MRI method not only during the treatment but also on later regular medical checks of tumor regression or progression.

Two 11-Years Periods Statistics and Trends of Enucleation and Evisceration.

PURPOSE: The indications for evisceration and enucleation are still evolving and controversial. The study aims to describe trends of enucleation versus evisceration in one center. METHODS: In period 1998-2019 were 353 patients were included in the study. Statistical results and Chi-square test for pair-wise comparisons for the statistical significance in comparing two subgroups (years periods 1998-2008 and 2009-2019) per category have been evaluated. RESULTS: The enucleation was performed in 306 patients, and the evisceration was performed in 47 patients. In 221 patients with the tumor exclusively enucleation was indicated. For the operation technique, the authors got a chi-square value of 0.027, and the associated P value is at 0.8695, then the number of evisceration and enucleation in subgroups have not confirmed independency. For the tumor presence, the authors got a chi-square value of 5.4, and the associated P value is at 0.02, then the number of validated/nonvalidated tumor presence in subgroups confirmed independency. CONCLUSIONS: The performed enucleations had 98% cases uveal melanoma, 1% of cases of another type of malignancy (lymphoma non-Hodgkin type), and 1% cases with benign tumor. Enucleation is also today most frequently due to malignant intraocular tumors, whereas evisceration if most frequently for the phthisis eye after a trauma or a previous intraocular surgery. In our study in 22 years interval also in the second period, there was an increased trend of enucleation due to intraocular malignancy. It can have many reasons, especially, that patients are sent to oncology centers late in the advanced stage of tumor.

SISCOM and FDG-PET in patients with non-lesional extratemporal epilepsy: correlation with intracranial EEG, histology, and seizure outcome.

AIMS: To assess the practical localising value of subtraction ictal single-photon emission computed tomography (SISCOM) coregistered with MRI and (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) in patients with extratemporal epilepsy and normal MRI. METHODS: We retrospectively studied a group of 14 patients who received surgery due to intractable epilepsy and who were shown to have focal cortical dysplasia, undetected by MRI, based on histological investigation. We coregistered preoperative SISCOM and PET images with postoperative MRI and visually determined whether the SISCOM focus, PET hypometabolic area, and cerebral cortex, exhibiting prominent abnormalities on intracranial EEG, were removed completely, incompletely, or not at all. These results and histopathological findings were compared with postoperative seizure outcome. RESULTS: Two patients underwent one-stage multimodal image-guided surgery and the remaining 12 underwent long-term invasive EEG. SISCOM findings were localised for all but 1 patient. FDG-PET was normal in 3 subjects, 2 of whom had favourable postsurgical outcome (Engel class I and II). Complete resection of the SISCOM focus (n=3), the area of PET hypometabolism (n=2), or the cortical regions with intracranial EEG abnormalities (n=7) were predictive of favourable postsurgical outcome. Favourable outcome was also encountered in: 4 of 8 patients with incomplete resection and 1 of 2 with no resection of the SISCOM focus; 4 of 7 patients with incomplete resection and 1 of 2 with no resection of the PET hypometabolic area; and 2 of 7 patients with incomplete resection of the area corresponding to intracranial EEG abnormality. No correlation between histopathological FCD subtype and seizure outcome was observed. CONCLUSION: Complete resection of the dysplastic cortex localised by SISCOM, FDG-PET or intracranial EEG is a reliable predictor of favourable postoperative seizure outcome in patients with non-lesional extratemporal epilepsy.