Novel diagnostic and therapeutic options in pituitary adenoma An enlightening approach

This thesis addresses several clinical questions regarding pituitary tumours through three observational studies and an intervention trial. In a prospective study in patients with sellar masses scheduled for pituitary surgery we found that these patients experience more severe headaches than controls with more pronounced relief at post-surgery follow-up, suggesting an additional positive effect of tumour resection. Psychological factors and/or a placebo effect are, however, not ruled out. Another observational study demonstrates signs of reduced photoentrainment of the biological clock in patients with a history of optic chiasm compression due to a pituitary tumour. These patients had an attenuated post-illumination pupil response to blue light and delayed sleep-wake timing, and may theoretically benefit from re-entrainment strategies. A subsequent prospective study focuses on signs of retinal damage in patients with optic chiasm compression before and after tumour resection. Preliminary findings show clear preoperative retinal thinning in patients with visual loss in comparison to those without. Thinning persisted at three months post-surgery, suggesting residual damage regardless of visual improvement. We furthermore performed a double-blind, placebo-controlled randomised trial on the somatostatin analogue lanreotide in patients with a ⁶⁸Ga-DOTATATE PET-positive non-functioning pituitary macroadenoma (NFMA): the GALANT trial. First of all, ⁶⁸Ga-DOTATATE uptake was demonstrated in >90% of NFMAs, providing evidence for somatostatin receptor expression in the majority of patients. The GALANT trial results reveal that lanreotide does not reduce tumour size or halt tumour growth in these patients. In essence, this thesis provides valuable insights regarding diagnostic and therapeutic options in pituitary adenoma.