Gamma Knife For Nonfunctioning Pituitary Adenoma

Objective: Nonfunctioning pituitary adenomas lack specific clinical manifestations,often with large tumors at the time of diagnosis,oppressing the optic nerve,invading the cavernous sinus,and being difficult to completely resect,remaining or recurring after surgery;patients unable to undergo surgery due to contraindications or subjectively strongly rejecting surgery.In the follow-up of these patients,the tumor often shows progress.According to experts and guidelines,we recommend gamma knife treatment.This article collected gamma knife treatment information and follow-up data for patients with nonfunctioning pituitary adenomas to evaluate the efficacy and safety of gamma knife for nonfunctional pituitary adenomas.Methods: The clinical data of 1,039 patients with pituitary adenoma treated between January 2000 and March 2015 in the Gamma Knife Center of the Second Hospital of Tianjin Medical University were retrospectively analyzed.Among them,patients with no functional pituitary adenoma who had been followed for more than 6 months followed up were 215 cases.Follow-up data included condition record,radiological and endocrine results during the review.Univariate analysis of factors affecting tumor control and post-treatment complications was performed,and a single factor with statistical significance was used for multivariate analysis.Results: There were 95 males(44.2%)and 120 females(55.8%).The mean age at treatment was 54.8(20-88 years)and the average follow-up time was 35.7 months(6-178 months).The median tumor volume at the time of positioning was 2.9 ml(0.2 ml to 56.6 ml),the median edge dose was 15 Gy,and the isodose line was 50%(45% to 60%).The average follow-up time was 35.7 months(6-178 months).The overall tumor control rate was 96.7%,postoperative group 96.2%,and first-line group 97.3%.In the univariate analysis of tumor progression factors,volume was a significant predictor of tumor progression.In multivariate analysis,volume is the most significant factor in tumor progression.Eighteen patients(9.94%)had new hypopituitarism on one or more hormone axes.In the univariate analysis of influencing factors,volume,invasiveness,and marginal dose were the influence factors.In multivariate analysis,marginal dose was a significant factor. Newly-impaired visual acuity decreased in 5 cases.There were no new patients with oculomotor and abducent nerve damage,and no other severe complications.Conclusion: 1.Nonfunctional pituitary adenomas are the first choice for surgical treatment.Not only can they quickly relieve the symptoms of the lesions,but they can also provide pathological results and guide the next step in diagnosis and treatment.2.It is feasible to diagnose non-functional pituitary adenoma based on the combination of MRI,endocrine examination and clinical manifestation.3.Gamma knife treatment of nonfunctional pituitary adenomas is a safe and effective treatment.Patients with inoperable pituitary adenomas who had residual or recurrence after surgery and those who could not undergo surgery or refused surgery showed good results,and there was no difference between the two groups.Small-sized tumors,mainly or all invasive in the cavernous sinus,inoperable due to contraindications,and subjective-looking nonfunctioning pituitary adenomas may be the first choice for gamma knife treatment.4.Volume and marginal doses are the main influencing factors for the prognosis of nonfunctional pituitary adenomas treated with Gamma Knife.That is to say,small tumor volume and increased marginal dose can highlight the therapeutic effect.There was no significant difference in the prognosis between the early and late phases of gamma knife treatment.However,early treatment of residual tumors is recommended to eliminate the risk of tumor progression.5.the main complication is hypopituitarism,marginal dose is the most important influencing factor.The most commonly damaged hormones are cortisol,thyroid hormones,and gonadotropins,which are often impaired early in follow-up.After gamma knife treatment,the incidence of intracranial nerve injury was extremely low.The most commonly damaged nerve was the optic nerve.Other serious complications such as radiation-induced neoplasia,tumor apoplexy are extremely rare.