Citations

Abstract BACKGROUND Stereotactic radiosurgery (SRS) is a safe and effective treatment for acromegaly. OBJECTIVE To improve understanding of clinical and dosimetric factors predicting biochemical remission. METHODS A single-institution cohort study of nonsyndromic, radiation-naïve patients with growth hormone-producing pituitary adenomas (GHA) having single-fraction SRS between 1990 and 2017. Exclusions were treatment with pituitary suppressive medications at the time of SRS, or <24 mo of follow-up. The primary outcome was biochemical remission—defined as normalization of insulin-like growth factor-1 index (IGF-1 i ) off suppression. Biochemical remission was assessed using Cox proportional hazards. Prior studies reporting IGF-1 i were assessed via systematic literature review and meta-analysis using random-effect modeling. RESULTS A total of 102 patients met study criteria. Of these, 46 patients (45%) were female. The median age was 49 yr (interquartile range [IQR] = 37-59), and the median follow-up was 63 mo (IQR = 29-100). The median pre-SRS IGF-1 i was 1.66 (IQR = 1.37-3.22). The median margin dose was 25 Gy (IQR = 21-25); the median estimated biologically effective dose (BED) was 169.49 Gy (IQR = 124.95-196.00). Biochemical remission was achieved in 58 patients (57%), whereas 22 patients (22%) had medication-controlled disease. Pre-SRS IGF-1 i ≥ 2.25 was the strongest predictor of treatment failure, with an unadjusted hazard ratio (HR) of 0.51 (95% CI = 0.26-0.91, P = .02). Number of isocenters, margin dose, and BED predicted remission on univariate analysis, but after adjusting for sex and baseline IGF-1 i , only BED remained significant—and was independently associated with outcome in continuous (HR = 1.01, 95% CI = 1.00-1.01, P = .02) and binary models (HR = 2.27, 95% CI = 1.39-5.22, P = .002). A total of 24 patients (29%) developed new post-SRS hypopituitarism. Pooled HR for biochemical remission given subthreshold IGF-1 i was 2.25 (95% CI = 1.33-3.16, P < .0001). CONCLUSION IGF-1 i is a reliable predictor of biochemical remission after SRS. BED appears to predict biochemical outcome more reliably than radiation dose, but confirmatory study is needed.

Abstract BACKGROUND Previously defined thresholds for total testosterone (TT) concentrations to screen for androgen-producing tumors (APTs) have used RIA, which can be less accurate in women. We aimed to define diagnostic thresholds to screen for APTs or postmenopausal pathologic hyperandrogenism using TT concentrations measured by Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS). METHODS We performed a retrospective cohort study on all women with TT ≥3.5 nmol/L and all postmenopausal women presenting with hyperandrogenism between 2004 and 2014 at the Mayo Clinic in Rochester, MN. RESULTS Of the 369 women with TT ≥3.5 nmol/L, 89 were included and subdivided into 3 groups based on their clinical diagnosis [21 (24%), APT; 16 (18%), postmenopausal pathologic hyperandrogenism; 52 (58%), polycystic ovary syndrome]. The source of the APT was more frequently ovarian (81%, n = 17) than adrenal (19%, n = 4). The diagnostic threshold using ROC analysis for TT to identify APT in women with severe biochemical hyperandrogenemia was ≥5.1 nmol/L (sensitivity, 90%; specificity, 81%). In a second analysis of a cohort of postmenopausal women only presenting with symptoms or signs of hyperandrogenism, median TT was significantly higher in the postmenopausal pathologic hyperandrogenism group (APT and ovarian hyperthecosis) vs the idiopathic hyperandrogenism group (4.9 vs 0.8 nmol/L; P &lt; 0.01). In postmenopausal women, the diagnostic threshold for pathologic hyperandrogenism was TT ≥2.2 nmol/L (sensitivity, 100%; specificity, 86%). CONCLUSIONS The diagnostic threshold for TT concentration as measured by LC-MS/MS to identify APT in women with biochemical severe hyperandrogenemia was TT ≥5.1 nmol/L. In postmenopausal women, the diagnostic threshold for pathologic hyperandrogenism was lower (TT ≥2.2 nmol/L).

SummaryObjectiveEvidence on the diagnostic performance of adrenal imaging is limited. We aimed to assess the diagnostic performance of unenhanced computed tomography (CT) and 18F‐fluorodeoxyglucose (18FDG) positron emission tomography (PET)/CT imaging in a high‐risk population for adrenal malignancy using an optimal reference standard.DesignRetrospective cohort study.MethodsImaging studies of patients with adrenal nodules who underwent adrenal biopsy and/or adrenalectomy between 1994 and 2014 were reviewed and compared to the reference standard of histology. Eighty % of patients presented with known or suspected extra‐adrenal malignancy.ResultsUnenhanced abdominal CT was performed in 353 patients with adrenal lesions; median size was 3 (0.7‐15) cm and median radiodensity was 33 (−21‐78) Hounsfield units (HU). Radiodensity of >10 HU diagnosed malignancy with a sensitivity of 100%, specificity of 33%, positive predictive value (PPV) of 72% and negative predictive value (NPV) of 100%. 18FDG‐PET/CT was performed in 89 patients; median tumour size was 2.1 (0.7‐9.2) cm. Maximum standardized uptake (SUV max) was higher in malignant lesions when compared to benign lesions (median=10 [2.3‐29.4] vs 3.7 [1.4‐24.5], respectively, P<.0001). Similarly, median SUV max lesion to SUV max liver ratio (ALR) in malignant lesions was higher than in benign lesions (median=3 [0.74‐13.4] vs 1.2 [0.5‐6.6], respectively, P<.0001). 18FDG‐PET/CT ALR >1.8 diagnosed malignancy with a sensitivity of 87%, specificity of 84%, PPV of 85% and NPV of 86%.ConclusionNoncontract CT radiodensity of ≤10 HU excludes malignancy even in a high‐risk population. For indeterminate adrenal lesions, given a superior specificity, 18FDG‐PET/CT could be considered as a second stage imaging study.

OBJECTIVENelson-Salassa syndrome (NSS) is a rare consequence of bilateral adrenalectomy (ADX) for refractory hypercortisolism due to Cushing disease (CD). Although classically defined by rapid growth of a large, invasive, adrenocorticotropin hormone (ACTH)–secreting pituitary tumor after bilateral ADX that causes cutaneous hyperpigmentation, visual disturbance, and high levels of ACTH, clinical experience suggests more variability.METHODSThe authors conducted a retrospective chart review of all patients 18 years and older with a history of bilateral ADX for CD, adequate pituitary MRI, and at least 2 years of clinical follow-up. Statistical tests included Student's t-test, chi-square test, Fisher's exact test, multivariate analysis, and derived receiver operating characteristic curves.RESULTSBetween 1956 and 2015, 302 patients underwent bilateral ADX for the treatment of hypercortisolism caused by CD; 88 had requisite imaging and follow-up (mean 16 years). Forty-seven patients (53%) had radiographic progression of pituitary disease and were diagnosed with NSS. Compared with patients who did not experience progression, those who developed NSS were significantly younger at the time of CD diagnosis (33 vs 44 years, p = 0.007) and at the time of bilateral ADX (35 vs 49 years, p = 0.007), had larger tumors at the time of CD diagnosis (6 mm vs 1 mm, p = 0.03), and were more likely to have undergone external-beam radiation therapy (EBRT, 43% vs 12%, p = 0.005). Among NSS patients, the mean tumor growth was 7 mm/yr (SE 6 mm/yr); the median tumor growth was 3 mm/yr. Prevalence of pathognomonic symptoms was low; the classic triad occurred in 9%, while hyperpigmentation without visual field deficit was observed in 23%, and 68% remained asymptomatic despite radiographic disease progression. NSS required treatment in 14 patients (30%).CONCLUSIONSNSS is a prevalent sequela of CD after bilateral ADX and affects more than 50% of patients. However, although radiological evidence of NSS is common, it is most often clinically indolent, with only a small minority of patients developing the more aggressive disease phenotype characterized by clinically meaningful symptoms and indications for treatment. Young age at the time of CD diagnosis or treatment with bilateral ADX, large tumor size at CD diagnosis, and EBRT are associated with progression to NSS and may be markers of aggressiveness.

Background: Systemic concentrations of T, estradiol (E2), GH, IGF-1, and IGF binding protein-3 decline in healthy aging individuals. Conversely, T and E2 stimulate GH and IGF-1 production in hypogonadal patients. Hypothesis: Because E2 stimulates GH secretion, putatively via the nuclear estrogen receptor-α and E2 and GH fall with menopause, we postulated that diminished endogenous E2 contributes to low GH output in older women. Location: The study was conducted at the Mayo Center for Clinical and Translational Science. Study Design: This was a randomized, double-blind, controlled study in 60 healthy postmenopausal women treated with the following: 1) double placebo; 2) anastrozole, a potent inhibitor of aromatase-enzyme activity, which mediates E2 synthesis from T; and/or 3) fulvestrant, a selective estrogen receptor-α antagonist. Methods: GH pulse generation was quantified by frequent GH sampling before and after short-term iv somatostatin infusion, thought to induce hypothalamic GHRH-mediated rebound-like GH secretion. Results: On anastrozole, E2 fell from 3.1 ± 0.35 pg/mL to 0.36 ± 0.04 pg/mL, and estrone from 13 ± 1.4 pg/mL to 1.9 ± 0.01 pg/mL (P &lt; .001) by mass spectrometry. Estrogen values were unchanged by fulvestrant. T concentrations did not change. One-hour peak GH rebound after somatostatin infusion declined markedly during both estrogen-deprivation schedules (P &lt; .001). Mean (150 min) maximal GH rebound decreased comparably (P &lt; .001). Measures of GH rebound correlated negatively with computed tomography-estimated abdominal visceral fat (all P &lt; .05). Conclusion: These data suggest a previously unrecognized dependence of hypothalamo-pituitary GH regulation on low levels of endogenous estrogen after menopause.

ObjectiveBeneficial effects of adrenalectomy on cardiovascular risk factors in patients with subclinical Cushing’s syndrome (SCS) are uncertain. We sought to conduct a systematic review and meta-analysis with the following objectives: (i) determine the effect of adrenalectomy compared with conservative management on cardiovascular risk factors in patients with SCS and (ii) compare the effect of adrenalectomy on cardiovascular risk factors in patients with SCS vs those with a nonfunctioning (NF) adrenal tumor.MethodsMEDLINE In-Process & Other Non-Indexed Citations, MEDLINE, EMBASE and Cochrane Central Register of Controlled Trial were searched on 17 November 2015. Reviewers extracted data and assessed methodological quality in duplicate.ResultsWe included 26 studies reporting on 584 patients with SCS and 457 patients with NF adrenal tumors. Studies used different definitions of SCS. Patients with SCS undergoing adrenalectomy demonstrated an overall improvement in cardiovascular risk factors (61% for hypertension, 52% for diabetes mellitus, 45% for obesity and 24% for dyslipidemia). When compared with conservative management, patients with SCS undergoing adrenalectomy experienced improvement in hypertension (RR 11, 95% CI: 4.3–27.8) and diabetes mellitus (RR 3.9, 95% CI: 1.5–9.9), but not dyslipidemia (RR 2.6, 95% CI: 0.97–7.2) or obesity (RR 3.4, 95% CI: 0.95–12). Patients with NF adrenal tumors experienced improvement in hypertension (21/54 patients); however, insufficient data exist for comparison to patients with SCS.ConclusionsAvailable low-to-moderate-quality evidence from heterogeneous studies suggests a beneficial effect of adrenalectomy on cardiovascular risk factors in patients with SCS overall and compared with conservative management.