International Journal of Radiation Oncology*Biology*Physics
Clinical investigation: brainStereotactic radiosurgery for patients with ACTH-producing pituitary adenomas after prior adrenalectomy
Introduction
Most patients with Cushing’s disease achieve biochemical remission after transsphenoidal surgery 1, 2. However, some patients have persistent adenoma causing adrenocorticotropic hormone (ACTH) overproduction and require repeated pituitary surgery (3), fractionated radiotherapy (RT) (4), or stereotactic radiosurgery 5, 6, 7. As an alternative to these adjuvant pituitary treatments, bilateral adrenalectomy can be performed to cure hypercortisolism 8, 9. The aggressive biologic nature of a subset of ACTH-secreting pituitary adenomas has been well-documented and termed Nelson syndrome 10, 11. The pituitary tumors in patients with Nelson syndrome may transform into pituitary carcinomas with the capacity for extracranial spread 12, 13. Fractionated RT has been reported to be protective against the development of Nelson syndrome after bilateral adrenalectomy 9, 14, 15. However, other studies have detected little benefit from RT for these patients 16, 17. In this report, we outline our 12-year experience with stereotactic radiosurgery for patients with ACTH-producing pituitary adenomas who have also undergone bilateral adrenalectomy.
Section snippets
Patients
Twelve female patients with ACTH-producing pituitary adenomas having bilateral adrenalectomy underwent radiosurgery at our center between March 1990 and June 1999. One patient died 3 months after radiosurgery of myocardial infarction and was excluded from additional analysis. The characteristics of the remaining 11 patients are detailed in Table 1. All patients had undergone ≥1 pituitary procedures (range 1–3). The median patient age was 42 years (range 26–76).
Radiosurgery and follow-up
All procedures were performed
Results
The tumor size remained stable (n = 6) or decreased (n = 3) in 9 (82%) of 11 patients. Two patients had tumor enlargement after radiosurgery. One patient had partial tumor coverage (18.5 cm3) and a tumor margin dose of 12 Gy. The second patient had complete tumor coverage (11.8 cm3) and a tumor margin dose of 16 Gy. This tumor appeared decreased in size until 39 months after the procedure, but then showed progressive enlargement. Both patients had Nelson syndrome (ACTH level 920 and 11,000
Discussion
Stereotactic radiosurgery provides biochemical remission of Cushing’s disease in >50% of treated patients 5, 6, 7. Sheehan et al. (7) reviewed 43 patients with Cushing’s disease treated between 1990 and 1998. In all patients, prior transsphenoidal surgery had failed. Twenty-seven patients (63%) had normal 24-h urinary free cortisol excretion at 12 months after radiosurgery. The authors argued that the ability of radiosurgery to provide endocrine normalization for a large proportion of patients
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Pituitary adenomas
2022, Progress in Brain ResearchNelson's Syndrome: An Update
2020, Endocrinology and Metabolism Clinics of North AmericaCitation Excerpt :Management of these patients is individualized and also tailored to previously offered treatments. Furthermore, the reported responses to treatment are variable and range from tumor stability (during variable monitoring intervals) to multiple growths and malignant transformation.1,4,6–8 In the latter scenario, there is poor prognosis and increased mortality.1–8,11,66
Prevention, diagnosis and treatment of Nelson's syndrome
2018, Current Opinion in Endocrine and Metabolic ResearchCitation Excerpt :In a study of 23 subjects with NS, Mauermann et al. reported effective decreases in ACTH levels in 67% and control of tumor growth in approximately 90% of patients following GKS [25]. While endocrinology criteria have not been widely reported, other groups have reported favorable tumor growth control rates with SRS as well [23,24,32,39,42]. Other modalities of delivering adjuvant radiation include linear accelerator (LINAC), SRS, LINAC fractionated stereotactic radiotherapy, and proton beam therapy [40,41].
Pituitary Tumors and Craniopharyngiomas
2015, Clinical Radiation OncologyNelson syndrome: Definition and management
2014, Handbook of Clinical NeurologyCitation Excerpt :However, such an association between pre-TBA urinary cortisol levels and risk of Nelson syndrome development post-TBA has not been demonstrated in some studies (Barnett et al., 1983; Kelly et al., 1983; Pereira et al., 1998), precluding adoption of urinary cortisol levels as a reliable predictive factor in clinical practice. Although it is possible that suboptimal or absent steroid replacement therapy may increase the risk of Nelson syndrome development post-TBA (Pollock and Young, 2002; Kasperlik-Zaluska et al., 2006), or promote the development of an aggressive tumor subtype (Banasiak and Malek, 2007; Nagesser et al., 2000), most studies have not shown this to be the case (Barnett et al., 1983; Kelly et al., 1983; Nagesser et al., 2000). It is possible that the minority (20%) of patients who lack suppression of cortisol on high-dose dexamethasone pre-TSS may be at higher risk of developing Nelson syndrome (Barber et al., 2010).
Stereotactic Radiosurgery of Pituitary Adenomas
2013, Neurosurgery Clinics of North America