Toward Improved Detection of Cholesteatoma Recidivism: Exploring the Role of Non-EPI-DWI MRI.

Background: Cholesteatoma is a lesion capable of destroying surrounding tissues, which may result in significant complications. Surgical resection is the only effective treatment; however, the presence of cholesteatoma recidivism is common. This study evaluated the effectiveness of the Attic Exposure-Antrum Exclusion (AE-AE) surgical technique in treating cholesteatomas and identifying factors associated with recidivism. Additionally, the study aimed to assess the utility of non-echo-planar diffusion MRI (non-EPI-DWI MRI) in detecting cholesteatoma recidivism in patients undergoing AE-AE surgery. Methods: The study involved 63 patients who underwent AE-AE surgery for primary acquired cholesteatoma and were followed up clinically and radiologically for at least five years. The radiological follow-up included a non-EPI-DWI MRI. Results: Results showed that the AE-AE technique successfully treated cholesteatomas, with a recidivism rate of 5.2%. The study also found that non-EPI-DWI MRI was a useful diagnostic tool for detecting cholesteatoma recidivism, although false positives could occur due to the technique's high sensitivity. As Preoperative Pure-tone average (PTA) increases, there is a higher probability of cholesteatoma recidivism in imaging tests (p = 0.003). Conclusions: Overall, the study highlights the importance of the AE-AE surgical technique and non-EPI-DWI MRI in managing cholesteatoma recidivism in patients, providing valuable insights into associated risk factors and how to manage recidivism. Non-EPI-DWI MRI can assist in patient selection for revision surgery, reducing unnecessary interventions and associated risks while improving treatment outcomes and patient care.

Clinical utility of intraoperative arterial spin labeling for resection control in brain tumor surgery at 3 T.

Resection control in brain tumor surgery can be achieved in real time with intraoperative MRI (iMRI). Arterial spin labeling (ASL), a technique that measures cerebral blood flow (CBF) non-invasively without the use of intravenous contrast agents, can be performed intraoperatively, providing morpho-physiological information. This study aimed to evaluate the feasibility, image quality and potential to depict residual tumor of a pseudo-continuous ASL (PCASL) sequence at 3 T. Seventeen patients with brain tumors, primary (16) or metastatic (1), undergoing resection surgery with iMRI monitoring, were prospectively recruited (nine men, age 56 ± 16.6 years). A PCASL sequence with long labeling duration (3000 ms) and postlabeling delay (2000 ms) was added to the conventional protocol, which consisted of pre- and postcontrast 3D T1 -weighted (T1w) images, optional 3D-FLAIR, and diffusion. Three observers independently assessed the image quality (four-point scale) of PCASL-derived CBF maps. In those with diagnostic quality (Scores 2-4) they evaluated the presence of residual tumor using the conventional sequences first, and the CBF maps afterwards (three-point scale). Inter-observer agreement for image quality and the presence of residual tumor was assessed using Fleiss kappa statistics. The intraoperative CBF ratio of the surgical margins (i.e., perilesional CBF values normalized to contralateral gray matter CBF) was compared with preoperative CBF ratio within the tumor (Wilcoxon's test). Diagnostic ASL image quality was observed in 94.1% of patients (interobserver Fleiss κ = 0.76). PCASL showed additional foci suggestive of high-grade residual component in three patients, and a hyperperfused area extending outside the enhancing component in one patient. Interobserver agreement was almost perfect in the evaluation of residual tumor with the conventional sequences (Fleiss κ = 0.92) and substantial for PCASL (Fleiss κ = 0.80). No significant differences were found between pre and intraoperative CBF ratios (p = 0.578) in patients with residual tumor (n = 7). iMRI-PCASL perfusion is feasible at 3 T and is useful for the intraoperative assessment of residual tumor, providing in some cases additional information to the conventional sequences.

Surgery guided by 5-aminolevulinic fluorescence in glioblastoma: volumetric analysis of extent of resection in single-center experience.

We analyzed the efficacy and applicability of surgery guided by 5-aminolevulinic acid (ALA) fluorescence in consecutive patients with glioblastoma multiforme (GBM). Thirty-six patients with GBM were operated on using ALA fluorescence. Resections were performed using the fluorescent light to assess the right plane of dissection. In each case, biopsies with different fluorescent quality were taken from the tumor center, from the edges, and from the surrounding tissue. These samples were analyzed separately with hematoxylin-eosin examination and immunostaining against Ki67. Tumor volume was quantified with pre- and postoperative volumetric magnetic resonance imaging. Strong fluorescence identified solid tumor with 100% positive predictive value. Invaded tissue beyond the solid tumor mass was identified by vague fluorescence with 97% positive predictive value and 66% negative predictive value, measured against hematoxylin-eosin examination. All the contrast-enhancing volume was resected in 83.3% of the patients, all patients had resection over 98% of the volume and mean volume resected was 99.8%. One month after surgery there was no mortality, and new or increased neurological morbidity was 8.2%. The fluorescence induced by 5-aminolevulinic can help to achieve near total resection of enhancing tumor volume in most surgical cases of GBM. It is possible during surgery to obtain separate samples of the infiltrating cells from the tumor border.