Coculescu M, Anghel R, Badiu C, Caragheorgheopol A, Hortopan D, Dumitrascu A, Virtej I, Trifanescu R, Capatana C, Voicu D

Additional effects of radiotherapy to dopamine agonists in the treatment of macroprolactinomas

Acta Endo (Buc) 2005, 1 (1): 43-59
doi: 10.4183/aeb.2005.43

INTRODUCTION: The aim of our study was to evaluate the cure rate of macroprolactinomas treated for a long term (> 4 years) or a short term (<4 years) with dopamine agonists (DA) alone or combined with radiotherapy (RT). Sometimes pituitary\r\nsurgery was performed.\r\nMATERIAL AND METHODS: We performed a retrospective study in 111 patients with macroprolactinomas, hospitalized in the Institute of Endocrinology, Bucharest, between 1978-2005. There were two groups, according to the length of DA therapy: group\r\nA =41 patients, treated more than 4 years and group B =70 patients, treated less than 4 years. Overall, 25 patients underwent additional radiotherapy, 13 in group A and 12 in group B. 28 patients were submitted to pituitary surgery, 9 in group A and 19 in group B.\r\nRESULTS: The cure rate (i.e. normalization of prolactin=PRL level and absence or minimal residual tumor mass, stable minimum 2 years after DA withdrawal) was 5/41 (12.1%) in group A and none in group B. 48 out of 111 patients achieved significant improvement (serum prolactin level less than 20 ng/ml and tumor shrinkage more than 50%) during DA therapy, but not after DA withdrawal: 17/41patients (41.5%) in group A and in 31/70 patients (44.3%) in group B, p=NS. Radiotherapy produced an additional improvement: in serum PRL levels only in group A, in 4/13 patients- 2/8 patients responsive to DA therapy and 2/5 patients resistant to DA therapy. In group B, the 3 patients resistant to DA submitted to radiotherapy were evaluated before the interval necessary for maximal effect of radiotherapy, but in 4/9 patients responsive to DA, we noticed further reduction in tumor volume, 2/4 progressing from mild to significant tumor shrinkage and ? progressing from no shrinkage to mild shrinkage. After radiotherapy, the medium prolactin level was 5.1 ng/ml in 10 patients from both groups on low bromocriptine (BRC) dose (7.5 mg/day), significantly less than in patients without radiotherapy, i.e. than in 19 patients from group A (serum PRL 49.5 ng/ml, p=0.02) and in 29 patients from group B (serum PRL 30.3 ng/ml, p=0.01). So, the daily BRC dose could safely decrease from 30 mg/day to 7.5 mg/day in those patients previously submitted to radiotherapy. Among 23 patients resistant to initial DA treatment, only 8 patients were submitted to radiotherapy, 2 became responsive to DA thereafter and 2 others obtained a significant decrease of prolactin levels.\r\nCONCLUSIONS: The overall cure rate is quite low in prolactinomas and it was noticed only after long-term treatment with dopamine agonists; it was improved up to 12.1% by the additional high voltage radiotherapy, useful even in DA resistant cases. The addition of radiotherapy is indicated for the cure of most prolactinomas.

Keywords: prolactinoma, radiotherapy, cure, dopamine agonists

Correspondence: Mihail Gr. Coculescu, Department of Endocrinology, ?Carol Davila? University of Medicine and Pharmacy, 34-36 Bd. Aviatorilor, Code 011863, Bucharest, Tel/Fax: + 4021 3198718, e-mail: m.coculescu@uni-davila.ro

References: