THE EFFICACY OF EARLY POSTOPERATIVE RADIOTHERAPY FOR NON-FUNCTIONING PITUITARY MACRO ADENOMAS, WITH TUMOUR CELLS EXPRESSING OR NOT EXPRESSING PITUITARY HORMONES

摘要

Background. Radiotherapy after surgery for non-functioning pituitary macro-adenomas (NFMAs) is still under debate.Aim. To appreciate the best timing for postoperative high voltage radiotherapy (hRT) in different type of NFMAs (classified using immunohistochemistry (IHC)).Subjects and Methods. Of 97 patients with a remnant (>1 cm) and IHC for anterior pituitary hormones, 41 patients (groups A & B) were submitted to hRT and followed up at least 5 years. RT was performed in 20/41 patients (Group A) within the first year after surgery, 21/41 patients (Group B) afterwards while in control group C, 56 patients were followed up without hRT. The progression of postoperative remnant was defined as a change of minimum of 25% of any diameter (transversal or vertical) by serial imaging studies.Results. The IHC of NFMAs revealed the following: 38 (39%) null cell, 29 (30%) gonadotropinomas, 12 (12%) silent plurihormonal, 11 (11%) silent corticotroph and 7 (7%) silent GH/PRL adenomas.Immunoreactive adenomas have relapse rate higher than null cell adenomas (ACTH> GH/ PRL> FSH/ LH> null cell) with a significant rate for silent ACTH 6/8 (75%). The null cell adenoma relapse rate was 6/23 (26%), p<0.009 in group without hRT. The relapse rate was significantly lower in group AB with hRT than in group without RT (p=0.025), at five years. Immediate hRT (applied within in first years) improved the control of the tumour growth in 90% (18/20) cases. In the group A, 10 % (2/20) patients relapsed than 24% (5/21) patients in group B and 39% (22/56) patients, Group C.Conclusion. An optimal time for radiotherapy is within the first year after the partial surgical removal of NFMAs, particularly if a large amount of residual tumour remains. Patients with silent corticotroph adenoma require special attention.