Endocrine Abstracts

Background: Radiotherapy is a third line treatment in Acromegaly. Pituitary radiotherapy (RT) is known to have cardiovascular complications (MI/IHD, CCF & CVA) due to radiation effects on normal pituitary and surrounding structures over and above the excess Growth hormone risk on metabolism (1).

Objective: To compare RT vs non-RT treated Acromegaly cohorts’ cardiovascular (CV) outcomes in unselected consecutive Acromegaly patients.

Methodology: Retrospective case notes and electronic records’ review consecutive Acromegaly patients with at least 1-year follow-up in University Hospitals of Leicester from 1957-2021 (UHL audit No:9300). Age-standardised IGF-1 levels were used to define remission status. PRISM software was used for statistics analysis.

Results: n = 132 (62 M: 70 F); mean follow up 17.8 yrs. Mean age 46.2 yrs (SD 13.4); 51:81::microadenomas:macrodenomas; 121/132 had transsphenoidal surgery; 53/132 had RT; 79/132 were in remission. 51% (27/53) of RT-group & 66% (52/79) of Non-RT were in remission. 63.6% increase in CV complications in RT-group (P < 0.0001) vs non-RT 40.5% (P < 0.0001) was noted. Diabetes, hypertension, hyperlipidaemia, OSA and dementia did not show meaningful difference.

Discussion: Diabetes, hypertension, hyperlipidaemia, IHD, MI, CCF and CVA increased substantially in entire Acromegaly cohort with marginal increased incidence of CV complications in RT-group compared to Non-RT despite no change in mean BMI at the latest assessment (28.6 vs 28.6). There was 6-fold increase CVA incidence in RT-group vs 2.5 fold in non-RT, similar to previously reported studies. This could be as a result of higher incidence of pituitary hormone deficiencies noted in RT vs non-RT group (4-fold in our audit), and potentially also from radiation-induced structural damage.

Conclusion: 1. Conservative approach to pituitary RT in Acromegaly patients could be considered in order to prevent long term morbidity especially in patients with pre-existent CV risk factors.

2. To be extra vigilant of CV complications in RT treated Acromegaly patients.