Primary versus postoperative stereotactic radiosurgery for acromegaly: a multicenter matched cohort study

Abstract

OBJECTIVEThe role of primary stereotactic radiosurgery (SRS) in patients with medically refractory acromegaly who are not operative candidates or who refuse resection is poorly understood. The aim of this multicenter, matched cohort study was to compare the outcomes of primary versus postoperative SRS for acromegaly.METHODSThe authors reviewed an International Radiosurgery Research Foundation database of 398 patients with acromegaly who underwent SRS and categorized them into primary or postoperative cohorts. Patients in the primary SRS cohort were matched, in a 1:2 ratio, to those in the postoperative SRS cohort, and the outcomes of the 2 matched cohorts were compared.RESULTSThe study cohort comprised 78 patients (median follow-up 66.4 months), including 26 and 52 in the matched primary and postoperative SRS cohorts, respectively. In the primary SRS cohort, the actuarial endocrine remission rates at 2 and 5 years were 20% and 42%, respectively. The Cox proportional hazards model showed that a lower pre-SRS insulin-like growth factor–1 level was predictive of initial endocrine remission (p = 0.03), whereas a lower SRS margin dose was predictive of biochemical recurrence after initial remission (p = 0.01). There were no differences in the rates of radiological tumor control (p = 0.34), initial endocrine remission (p = 0.23), biochemical recurrence after initial remission (p = 0.33), recurrence-free survival (p = 0.32), or hypopituitarism (p = 0.67) between the 2 matched cohorts.CONCLUSIONSPrimary SRS has a reasonable benefit-to-risk profile for patients with acromegaly in whom resection is not possible, and it has similar outcomes to endocrinologically comparable patients who undergo postoperative SRS. SRS with medical therapy in the latent period can be used as an alternative to surgery in selected patients who cannot or do not wish to undergo resection.

Prospective Intraoperative and Histologic Evaluation of Cavernous Sinus Medial Wall Invasion by Pituitary Adenomas: Implications for Acromegaly Outcomes

“…These results offer the potential to improve surgical outcomes in neuroendocrine tumors; particularly in acromegaly, where somatotroph adenomas now appear to have an intrinsic propensity to invade the cavernous sinus wall with very high frequency across both high and low Knosp grades. The increasing use of stereotactic radiation to treat cavernous sinus disease has had mixed results with a signi cant time interval to achieve remission from treatment onset [35][36][37][38][39][40][41] . Furthermore, the morbidity associated with permanent cranial neuropathies with radiation may not be better than the safety pro le of medial wall resection by experienced groups, although more research is warranted in this area 35 .…”

Tercer Consenso Nacional de Acromegalia: recomendaciones para su diagnóstico, tratamiento y seguimiento

“…En la RT estereotáctica (RTE) se administran dosis mayores de radiación al tejido blanco, con mayor precisión para localizar el tumor 80 , permitiendo menores efectos secundarios y menor tiempo de latencia para control bioquímico (2 años) 89 . Esta es la terapia de elección a menos que el tumor esté muy cercano al quiasma óptico o exista demasiado tumor residual, con más de 3 cm 23,85 .…”

“…Este incremento de mortalidad no ha sido demostrado con las nuevas modalidades de RT 75,85 . Se considera que el riesgo de hipopituitarismo es menor con Rqx 89 ; sin embargo, el seguimiento a largo plazo es limitado y existe demasiada heterogeneidad en los estudios que dificulta realizar esta comparación. Se requieren estudios con mayor tiempo de seguimiento que evalúen los efectos a largo plazo incluyendo mortalidad y EVC, para comprobar si las posibles ventajas mencionadas de la Rqx se mantienen a largo plazo 85,90 .…”

Acromegaly in the elderly patient

“…Based on data reported in large retrospective studies and systematic reviews young and older patients show similar local control and toxicity after either radiosurgery or fractionated stereotactic radiotherapy (65,(67)(68)(69). Single-fractions doses of 20-28 Gy are usually employed for acromegaly (65,(67)(68)(69).…”