Non‐functioning pituitary adenomas: indications for postoperative radiotherapy

Abstract

To determine the indications for postoperative radiotherapy after surgical resection of a nonfunctioning pituitary macroadenoma. A retrospective chart review of 72 patients with histologically proven chromophobe adenoma who presented for pituitary surgery between January 1985 and June 1998, with a minimum follow-up period of 12 months. The study endpoint was tumour recurrence or progression detected either by routine follow-up imaging or by clinical progression with subsequent confirmation by imaging. A proportional hazards model was used to determine independent prognostic factors. Mean follow-up was 64 months. In the radiotherapy group 13 of 50 recurred (or progressed) (26%), while in the nonradiotherapy group 10 of 22 recurred (46%), logrank test, P = 0.025. In patients assessed as having complete excision of tumour (n = 20) only two recurred (10%), both in patients without radiotherapy. No further treatment has been required in either case to date. In patients with residual tumour (n = 52), 41 had radiotherapy with 13 recurrences (32%), while 11 patients had no radiotherapy with eight subsequent recurrences (73%); logrank test, P = 0.007. Further treatment has been required in the majority of these cases. Cox's proportional hazards model analysis showed that only complete tumour removal and postoperative radiotherapy were independent favourable prognostic factors. The goal of surgery should be complete surgical excision where possible. The risk of recurrence in patients with no residual tumour on postoperative imaging is low enough to justify withholding routine postoperative radiotherapy in this group. In patients with residual tumour, conventional external beam radiotherapy administered within 12 months of surgery is effective at reducing recurrence or progression.

Presentation and surgical results of incidentally discovered nonfunctioning pituitary adenomas: evidence for a better outcome independently of other patients' characteristics

“…This variability reflects different surgical expertise, different criteria to define recurrence, the length of follow-up, and the use of postoperative radiotherapy (28). Incomplete removal is strongly associated with recurrence of NFPA (2,23,27,29,30), while adjuvant radiotherapy is very effective in reducing the risk of tumor regrowth (2,30,31). Our results show that patients with asymptomatic NFPA have a lower risk of tumor recurrence (HR of 0.30) than that of patients with symptomatic NFPA that is independent of all other characteristics, including the presence of postoperative remnants and utilization of radiotherapy.…”

The natural course of non-functioning pituitary macroadenomas

“…Some studies report, to a variable degree, an improvement in pituitary function (4,(7)(8)(9)(10)(11), whereas others could not demonstrate significant improvement in pituitary function, or even showed decreased pituitary function after transsphenoidal surgery (5,12,13). Transsphenoidal surgery leads to long-term tumor control in approximately 80% of patients (3,(14)(15)(16), and, in selected series, in even more than 90% of the patients (15,17).…”

Early versus late Gamma Knife radiosurgery following transsphenoidal resection for nonfunctioning pituitary macroadenomas: a matched cohort study

“…2,5,31,32,43,56 Previously reported long-term outcomes following transsphenoidal surgery for nonfunctioning macroadenomas suggest that even gross-total resection carries a 10% to 20% rate of tumor recurrence at distant follow-up. 6,8,9,13,19,21,34,43,46,58,64,66 Subtotal resection without adjuvant treatment reportedly results in the progression of adenoma growth in 50% to 60% of patients within 10 years of surgery. 9,22,34,43,46,48 For these reasons, patients with nonfunctioning tumors may undergo secondary operations and/ or adjuvant radiotherapy for the treatment of residual or progressive disease.…”