2026 Proffered Presentations
S177: PINEAL TUMORS, A DESCRIPTIVE ANALYSIS OF 28 YEARS OF EXPERIENCE WITH VOLUMETRIC ANALYSIS OF DIFFERENT APPROACHES AND ITS COMPLICATIONS
Martin A Pilonieta, Pediatric Neurosurgeon1; An Lesage, Radiologist2; Volodia Dangouloff, Radiologist2; Raphael Levy, Radiologist2; Kevin Beccaria2; 1Hospital Infantil Universitario; 2Hôpital Necker Enfants-Malades
Background: Pineal region tumors in pediatric population a concern being 3-11% of all pediatric brain tumors. Given the complex anatomy of this region, and the presence of important neurovascular structures, several approaches have been described. We performed an analysis of the different approach used in our institution focused on two main approaches: Occipital Transtentorial approach (OTA) and Supracebellar Infratentorial approach (SCITA).
Methods: 80 patients were operated of pineal tumors, with 24 re-operations for tumor resection. Retrospective data were collected, and for 50 patietns we were able to collect pre and post-surgical MRI, making analysis of pre and post tumor volume as well as clinical and radiological complications evidenced in post-surgical MRI.
Results: we found 80 patients with a median age of 9.25 years old, with a male predominance (65,8%). The most common pathology was pinealoblastome with 23.9%, followed by germinome and pylocitic astrocitome both with 20%. A total of 105 craniotomies were performed, OTA was used in 54 cases, SCITA was used in 37 cases, and there were other approaches such as SCITA with telovelar extension in 10 patients, and OTA with tanscallosal extension in 5 patients. There was no mortality related to surgery. We found that the rates of total resection was similar between OTA and SCITA, being 62.3% and 62.8% respectively, however, OTA patients had a significant bigger volume pre-op (p = 0.0089). Meanwhile, there were 22.8% and 52.4% of subtotal resection in SCITA and OTA respectively, again, here there was a significant difference in pre-op tumor volume ( p= 0.0002) being OTA tumor bigger. We measured some anatomical charatcteristics of the tumors such as inclination of the tentorium, or space available over the culmen of cerebellum, however, there were no differences in these variables between both approaches, which would mean that this variables were not considered for choosing the approach. The presence of complications was significantly different based on the approach chosen, among those were palpebral ptosis, visual disturbances, Parinaud syndrome, need of subdural -peritoneal shunt. However, when we compare post MRI alterarions there were no differences between both approaches. We also made a logistic regression model to try to predict post-op deficit, were we found that the only significant variable was pre-operative volume.
Conclusions: Pineal tumors are not a that uncommon entity in pediatric population, which makes them important. Having several approaches to the pineal region, we could identify that OT approaches have the same rate of complete resection, compared to SCITA, however, it seems to be more efficient for bigger tumors. We could show that the different anatomical variables measured as inclination of the tentorium and over culmen width of the cistern were not considered for choosing the approach. Despite having different profiles of complications both have a similar rate of abnormal findings in postop MRI, and with our logistic regression model, the sole significant variable to predict pot-op complication was pre-op tumor volume.