Natural history of post-operative non-functioning pituitary adenomas – a single centre cohort analysis

Abstract

Purpose

To study behaviour of endonasally operated non-functioning pituitary adenomas (NFPA) and propose a cost-effective stratified follow-up regimen.

Methods

A single centre retrospective cohort analysis from June 2009 till December 2019. All endonasally operated pituitary adenomas were identified with sub-analysis of the NFPA’s. Patients of all age groups with radiological follow-up more than 30 months were included. Patients with any kind of cranial intervention performed < within 30 months of surgery were excluded. The post-operative MRI for this cohort was evaluated until either any intervention was performed or until the last follow-up. The maximal tumour diameter in any plane (mm) was measured from the MRI scans. The annual growth rate and the statistical relationship between age, sex, IHC, Ki-67, resection %, residual tumour was calculated.

Results

Out of 610 pituitary adenomas identified in the dataset, 116 patients met the inclusion criteria. Follow-up period ranged from 30 to 142 months (mean 78.5 months). A strong relationship existed between predicting tumour progression with first post-operative residue size (p = .001). A statistically significant relationship was found to be present between tumour growth and a residue of less than 10 mm diameter and 11–20 mm in diameter (Log rank p value .0216). On average, each patient with a residue < 5mm had MRI scans costing 976 £.

Conclusion

Based on statistical analysis and internal validation of the growth rate of the residue, we have proposed MRI follow-up scans. These recommendations have the potential to save more than 300 £per patient towards MRI costs and can lay down a marker for defining time interval of serial scans for post-operative NFPA’s.

Keywords:

• Growth rate
• non-functioning
• pituitary adenomas
• radiology

Acknowledgement

The authors would like to acknowledge Ms Sanya Jha for helping with the statistics.

Ethical approval

For this type of study formal consent of ethics committee was not required.

Consent form

In this retrospective observational study, no patient identifying details have been used.

Previous presentations

Presented at Society of British Neurological Surgeons Conference September 2022.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

No funding was received for this research.