Surgical outcomes in patients with endoscopic versus transcranial approach for skull base malignancies: a 10-year institutional experience.

OBJECT: The authors performed an extensive comparison between patients treated with open versus an endoscopic approach for skull base malignancy with emphasis on surgical outcomes. METHODS: A single-institution retrospective review of 60 patients who underwent surgery for skull base malignancy between 2009 and 2018 was performed. Disease features, surgical resection, post-operative morbidities, adjuvant treatment, recurrence, and survival rates were compared between 30 patients who received purely open surgery and 30 patients who underwent purely endoscopic resection for a skull base malignancy. RESULTS: Of the 60 patients with skull base malignancy, 30 underwent open resection and 30 underwent endoscopic resection. The most common hisotype for endoscopic resection was squamous cell carcinoma (26.7%), olfactory neuroblastoma (16.7%), and sarcoma (10.0%), and 43.3%, 13.3%, and 10.0% for the open resection cohort, respectively. There were no statistical differences in gross total resection, surgical-associated cranial neuropathy, or ability to achieve negative margins between the groups (p > 0.1, all comparisons). Patients who underwent endoscopic resection had shorter surgeries (320.3 ± 158.5 minutes vs. 495.3 ± 187.6 minutes (p = 0.0003), less intraoperative blood loss (282.2 ± 333.6 ml vs. 696.7 ± 500.2 ml (p < 0.0001), and shorter length of stay (3.5 ± 3.7 days vs. 8.8 ± 6.0 days (p < 0.0001). Additionally, patients treated endoscopically initiated adjuvant radiation treatment more quickly (48.0 ± 20.3 days vs. 72.0 ± 20.5 days (p = 0.01). CONCLUSIONS: An endoscopic endonasal approach facilitates a clinically meaningful improvement in surgical outcomes for skull base malignancies.

The Role of Advanced Endoscopic Resection of Diverse Skull Base Malignancies: Technological Analysis during an 8-Year Single Institutional Experience.

Background Resection of skull base malignancies poses complex pathological and treatment-related morbidities. Recent technological advancements of endoscopic endonasal surgery (EES) offer the ability to reexamine traditional treatment paradigms with endoscopic procedures. The utility of EES was quantitatively examined in a longitudinal series with attention to morbidities and postoperative outcomes. Methods A single-center retrospective review was performed of all malignant sinonasal tumors from 2010 to 2018. Patients with purely EES were selected for analysis. Disease features, resection extent, complications, adjuvant treatment, recurrence, and survivability were assessed. Despite the mixed pathological cohort, analysis was performed to identify technical aspects of resection. Results A total of 68 patients (47.6% males and 52.4% females, average age: 60.3 years) were included. A diversity of histotypes included clival chordoma (22.1%), olfactory neuroblastoma (14.7%), squamous cell carcinoma (11.8%), and adenoid cystic carcinoma (11.8%). Gross total resection (GTR) was achieved in 83.8% of cases. Infection (4.4%) and cerebrospinal fluid leak (1.5%) were the most common postoperative complications. Total 46 patients (67.6%) underwent adjuvant treatment. The average time between surgery and initiation of adjunctive surgery was 55.7 days. Conclusion In our 8-year experience, we found that entirely endoscopic resection of mixed pathology of malignant skull base tumors is oncologically feasible and can be accomplished with high GTR rates. There may be a role for EES to reduce operative morbidity and attenuate time in between surgery and adjuvant treatment, which can be augmented through recent mixed reality platforms. Future studies are required to systematically compare the outcomes with those of open surgical approaches.

Pituitary adenoma consistency: Direct correlation of ultrahigh field 7T MRI with histopathological analysis.

PURPOSE: Tumor consistency is a critical factor in surgical planning that influences ease of resection and risk of operative morbidity. The ability of MRI to predict tumor consistency tumor consistency has been shown to increase with higher field strength. The present study examined the utility of 7 T (7 T) MRI in predicting the tumor consistency of pituitary adenomas. METHOD: Fifteen patients with pituitary adenomas were preoperatively scanned at 7 T MRI. Regions of interest were drawn around lesions for voxel-based signal intensity (SI) analysis. The percentage of tumor voxels with intensity higher than local gray matter was calculated on T2-weighted imaging. A single neurosurgeon rated tumor firmness for all patients. Histopathological analysis was performed. Radiological tumor features were correlated with intraoperative tumor consistency measurements and histopathology. RESULTS: Tumors rated as 'soft' intraoperatively were hyperintense to local gray matter on T2-weighted imaging. 'Firm' tumors were hypointense to local gray matter. There was no significant difference in SI ratio between soft and firm tumors (p = 0.098). Soft tumors had a significantly higher percentage of tumor voxels greater than local gray matter compared to firm tumors (p = 0.035, Cohen's D-effect size = 1.208). Soft tumors had higher vascularity than firm tumors, p = 0.015. CONCLUSIONS: The signal and contrast advantage conferred by 7 T MRI may provide valuable preoperative information regarding pituitary tumor consistency and physiology. The use of granular, voxel-based analysis maximizes the potential afforded by the high resolution of 7 T imaging, and may be a valuable method of predicting consistency of pituitary adenoma.

Electronic expert consultation using digital still images for evaluation of atypical small acinar proliferations of the prostate: a comparison with immunohistochemistry.

This study was performed on a series of prostate needle biopsies with diagnosis of atypical small acinar proliferation (ASAP) to verify to what extent the application of immunohistochemistry (IHC) for p504s and p63 markers as well as expert consultation by still images could affect the diagnosis. The results of these 2 methods were compared. Immunohistochemistry staining for p504s and p63 was performed on sections from 42 patients with a primary diagnosis of ASAP. Meanwhile, digital still images were taken from hematoxylin and eosin-stained slides of cases and were sent to an expert uropathologist, blind to IHC staining interpretations. The results of IHC staining were compared with diagnostic interpretations of the consultant pathologist. In 13 cases, the focus of concern was not detectable on IHC slides. In the remaining 29 cases, IHC showed a benign and malignant expression pattern in 17 and 9 patients, respectively. In 3 cases, IHC findings were inconclusive and retained the diagnosis of ASAP. The consultant pathologist diagnosed 11 cases of benign and 7 cases of malignant processes. He retained the diagnosis of ASAP in 11 cases. There was high concordance between the results of IHC and electronic consultation in the group of benign cases. All 11 cases with the diagnosis of benignancy by electronic consultation showed a benign IHC pattern. Among 7 cases with the diagnosis of malignancy by the consultant pathologist, 5 were classified as malignant, 1 as benign, and 1 as inconclusive IHC groups. Considering problems with IHC staining of prostate needle biopsy, including loss of focus of interest, expert consultation using still images can provide very useful diagnostic information. This approach can be used as an adjunct to other diagnostic activities like IHC or even as an independent source of information to reach more accurate diagnoses in ASAP cases, particularly in institutions with limited resources.

Progressive transmission of images over fading channels using rate-compatible LDPC codes.

In this paper, we propose a combined source/channel coding scheme for transmission of images over fading channels. The proposed scheme employs rate-compatible low-density parity-check codes along with embedded image coders such as JPEG2000 and set partitioning in hierarchical trees (SPIHT). The assignment of channel coding rates to source packets is performed by a fast trellis-based algorithm. We examine the performance of the proposed scheme over correlated and uncorrelated Rayleigh flat-fading channels with and without side information. Simulation results for the expected peak signal-to-noise ratio of reconstructed images, which are within 1 dB of the capacity upper bound over a wide range of channel signal-to-noise ratios, show considerable improvement compared to existing results under similar conditions. We also study the sensitivity of the proposed scheme in the presence of channel estimation error at the transmitter and demonstrate that under most conditions our scheme is more robust compared to existing schemes.