Towards Defining the Optimal Imaging Schedule Following Pituitary Tumor Resection

Presentation Number: SAT-0636
Date of Presentation: June 21st, 2014

Jelena Maletkovic*1, Marilene B. Wang2, Marvin Bergsneider2 and Anthony P Heaney3
1UCLA David Geffen School of Medicine, Los Angeles, CA, 2David Geffen School of Medicine at UCLA, Los Angeles, CA, 3UCLA-David Geffen Schl of Med, Los Angeles, CA

Abstract

BACKGROUND: Pituitary tumors are common and typically extremely slow-growing benign adenomas. Following surgical pituitary resection imaging schedules to assess for recurrence and for growth of tumor residual vary and there is no clear consensus on the optimal imaging interval and duration of post-op imaging. At our center MRI of the pituitary is performed 3 and 12 months after surgery and then annually for 3-5 years. Advances in neurosurgical techniques have enabled more complete resection of even extensive macroadenomas. We sought to re-evaluate our current imaging schedule and document tumor recurrence and regrowth rates.

METHODS: Retrospective analysis of a database identified 215 skull-base surgeries between 2008- 2010 performed by a single surgical team (MB & MW).  Patients with sellar masses other than pituitary tumors were excluded leaving a total of 163 patients. 74 patients had a minimum of 3 year follow up following tumor resection. 8 patients who received radiation for extensive residual tumor were excluded from analysis. MRI scans in the remaining 66 patients were analyzed for the presence of residual tumors on the first postoperative 3 month image. Patients that exhibited growth of existing tumor residue or developed new recurrence were identified over the follow up period.

RESULTS: 45 of 66 (68%) patients had no visible tumor on MRI study 3 months post-op. 38 of these patients (58%) exhibited no recurrence or residual tumor during the 3 year follow up. One patient had tumor recurrence at the 2 year time point. Six of the 45 patients (13%) had questionable tumor recurrence after one or two years but this could not be distinguished from post-operative changes and did not change across the  3 year study.

Of the remaining 21 of all 66 patients (31%), 9 (14%) were reported as probable residual tumor at 3 months. The “probable” residual tumor has remained stable in 7 patients and decreased in 1 patient over the follow up period. In 1 patient with probable residual tumor, tumor growth was seen after two years. 12 patients (18%) had definite residual tumor on the 3 month post-op MRI. Only one of these patients exhibited tumor growth after 3 years whereas tumor residual remained stable in 10 patients and decreased in 1 patient.

In summary, of 45 patients who had no tumor visible at 3 months post-op 1 patient (2%) has demonstrated definite recurrent tumor. Of 9 patients that were initially reported as possible residual tumor, one patient (11%) demonstrated tumor growth over the 3 year interval. Finally of 12 patients that had definite tumor visible at 3 months post-op, tumor growth occurred in only 1 patient (8%).

CONCLUSION:  Recurrence or growth of tumor residual is very uncommon (3 of 66, 4.5%) in the vast majority of pituitary tumors. Given the improved surgical resection  now attainable in most pituitary tumors our data serve to generate discussion about the optimal imaging schedule in patients with pituitary tumors.

 

Nothing to Disclose: JM, MBW, MB, APH