The benefit and risk of stereotactic radiosurgery for prolactinomas: an international multicenter cohort study

Abstract

<jats:sec><jats:title>OBJECTIVE</jats:title><jats:p>The most common functioning pituitary adenoma is prolactinoma. Patients with medically refractory or residual/recurrent tumors that are not amenable to resection can be treated with stereotactic radiosurgery (SRS). The aim of this multicenter study was to evaluate the role of SRS for treating prolactinomas.</jats:p></jats:sec><jats:sec><jats:title>METHODS</jats:title><jats:p>This retrospective study included prolactinomas treated with SRS between 1997 and 2016 at ten institutions. Patients’ clinical and treatment parameters were investigated. Patients were considered to be in endocrine remission when they had a normal level of prolactin (PRL) without requiring dopamine agonist medications. Endocrine control was defined as endocrine remission or a controlled PRL level ≤ 30 ng/ml with dopamine agonist therapy. Other outcomes were evaluated including new-onset hormone deficiency, tumor recurrence, and new neurological complications.</jats:p></jats:sec><jats:sec><jats:title>RESULTS</jats:title><jats:p>The study cohort comprised 289 patients. The endocrine remission rates were 28%, 41%, and 54% at 3, 5, and 8 years after SRS, respectively. Following SRS, 25% of patients (72/289) had new hormone deficiency. Sixty-three percent of the patients (127/201) with available data attained endocrine control. Three percent of patients (9/269) had a new visual complication after SRS. Five percent of the patients (13/285) were recorded as having tumor progression. A pretreatment PRL level ≤ 270 ng/ml was a predictor of endocrine remission (p = 0.005, adjusted HR 0.487). An increasing margin dose resulted in better endocrine control after SRS (p = 0.033, adjusted OR 1.087).</jats:p></jats:sec><jats:sec><jats:title>CONCLUSIONS</jats:title><jats:p>In patients with medically refractory prolactinomas or a residual/recurrent prolactinoma, SRS affords remarkable therapeutic effects in endocrine remission, endocrine control, and tumor control. New-onset hypopituitarism is the most common adverse event.</jats:p></jats:sec>

Gamma Knife Radiosurgery for Pituitary Tumors: A Systematic Review and Meta-Analysis

“…The probability of obtaining normalization of remission is, in fact, generally lower than 50%. Interestingly, the remission rate between the larger multicenter studies by Hung et al is similar to that reported in smaller series [ 49 ]. The probability of normalizing PRL levels by combining GK and dopamine agonists approaches 50–70% at five years [ 39 , 49 , 50 ].…”

“…Only four studies on GK treatment for prolactinomas were included in this systematic review and meta-analysis ( Table 4 ) [ 48 , 49 , 50 , 51 ]. Typically such patients have larger and regionally invasive tumors with PRL levels that indicate cavernous sinus invasion.…”

“…However, random effects meta-analysis for remission of hyperprolactinemia are shown in Figure 5 , with estimates of 35% (95% CI: 17–53%; I 2 = 91%, p < 0.001). Only the multi-institutional study by Hung et al reported the five-year RFS (41%) [ 49 ]; no pooled analyses were thus possible. Recurrence of hyperprolactinemia after hormonal remission occurs uncommonly; in the two larger studies, 8% and 5% of patients had a recurrence of disease.…”

“…The probability of normalizing PRL levels by combining GK and dopamine agonists approaches 50–70% at five years [ 39 , 49 , 50 ]. A lower PRL level before GK (a sign of less tumor invasiveness of regional structures such as the cavernous sinus) is associated with better hormonal remission in several studies [ 34 , 49 ].…”

Patient-Reported Outcome (PRO) as an Addition to Long-Term Results after High-Precision Stereotactic Radiotherapy in Patients with Secreting and Non-Secreting Pituitary Adenomas: A Retrospective Cohort Study up to 17-Years Follow-Up

“…Very few patients developed radiosurgery-related hypopituitarism. Hong and colleagues reported on 289 patients with prolactinomas treated with GKS at ten international centers [35]; the endocrine remission rates were 28%, 41%, and 54% at 3, 5, and 8 years, respectively, after SRS. In that study, however, 25% of all patients reported new treatment-related hormonal deficiencies and 3% of all patients developed visual complications related to SRS.…”