Endocrine Abstracts (2017) 49 EP1030 | DOI: 10.1530/endoabs.49.EP1030

Hormone and tumor responses to primary or pre-operative therapy with somatostatin analogs in acromegaly and the relation with T2-weighted MRI signal

Maria Picallo, Rogelio Garcia Centeno, Aurelio Lopez Guerra, Yoko Lucia Olmedilla, Maria Arnoriaga, Maria Requena, Javier Agreda, Victor Andia, Marcel Sambo, Susana Monereo, Maria Angeles Velez, Bettina Weber & Jose Atencia

Gregorio Marañon Hospital, Madrid, Spain.

Objective: Study of the efficacy of SSA in the biochemical and tumour control and the relation between the T2-weighted MRI signal intensity and the response to SSA.

Material and methods: 16 patients with GH-secreting pituitary adenomas (7♂/9♀) that received primary or pre-operative treatment with SSA. We classified them according to baseline T2-weighted MRI sequences as Hypo-intense (Ha) and No-Hypo-intense adenomas (no-Ha). Results expressed like media (S.D.).

Results: Median age at diagnosis was 50.6 (18.5) years. 10 patients (9 macroademonas) had pre-operative therapy with SSA during 18.58 (26.9) months, with 47.2% decrease in IGF1 levels and 24.5% of tumour shrinkage. After neurosurgery three patients required medication for hormonal control. Only one patient had postsurgical complications (hypopituitarism). Six patients (two macroadenomas) received exclusively medical treatment during 59.77(64.5) months. They showed 56.8% of reduction in IGF1 levels and 49% of tumour shrinkage. In the last consultation, 4 achieved hormonal control and two needed dose adjustment. From the whole group, ten were no-Ha and 6 Ha, showing at diagnosis: GH 20.13(16.5) vs 14.75(19.8) μg/l, IGF1 973.5(474) vs 703.7(243.5) μg/l and a maximum diameter of 15.9(11) vs 12.05(4.95) mm, respectively. After 6 months of SSA therapy there was 51.2% decrease in IGF1 levels in No-Ha vs 72.3% in Ha. Six of the No-Ha had surgery and four of the Ha. The hormonal response in No-Ha was complete in the 50% and partial in 20% of patients vs 83% and 17% in Ha, respectively. >20% of tumour shrinkage occurred in 40% of the No-Ha vs 66% of the Ha.

Conclusions: Our results show the effectiveness of the pre-operative treatment with SSA in the acromegaly, in terms of hormonal but also anti-tumoral effects. T2-signal intensity at diagnosis it’s a good prognostic marker of the effectiveness of SSA therapy and it’s correlated with the tumour size-invasion and hormone levels at diagnosis.