Lewis S. Blevins

The Efficacy of Linear Accelerator Radiosurgery in the Management of Patients with Cushing’s Disease

We identified 35 patients who had undergone stereotactic radiosurgery (SRS) for their biochemically proven Cushing’s disease in order to assess the efficacy of SRS with regard to control of hypercortisolism, improvement of clinical features and prevention of tumor progression, and subsequent incidence of hypopituitarism. Seventeen (49%) patients achieved control of their cortisol levels following SRS; the mean time to normalization was 7.5 months (range: 1–33). Four (19%) patients experienced recurrent hypercortisolism at a mean time of 35.5 months following therapy (range: 17–64). Control of tumor progression was achieved in 91% patients. Fourteen (40%) patients demonstrated a new pituitary deficiency following SRS. Our results suggest that cortisol levels are normalized more efficiently and with a lower recurrence rate with SRS than with conventional fractionated external beam radiotherapy (EBT). We have confirmed the near 100% tumor control rate reported with SRS. The percentage of patients developing pituitary insufficiency following SRS is less than that of patients having undergone EBT; however, deficits occurred up to 10 years posttreatment. We advocate the use of SRS as the primary therapeutic modality in those patients who are poor surgical candidates, or as the adjunct treatment to microsurgery in eliminating residual tumor cells or disease that is not easily amenable to resection.

Prevalence of valvular heart disease in a cohort of patients taking cabergoline for management of hyperprolactinemia.

OBJECTIVE To determine the prevalence of valvular heart disease in a cohort of patients taking cabergoline for the management of hyperprolactinemia. METHODS A retrospective review of medical records identified patients with hyperprolactinemia who underwent evaluation at Vanderbilt University Medical Center between January and June 2007. The medical records of those patients who were prescribed cabergoline and who underwent elective echocardiography were reviewed for details pertaining to cardiac valvular abnormalities and cabergoline use. RESULTS Forty-five patients (mean age, 41 +/- 10 years [SD]) taking 0.91 +/- 0.96 mg of cabergoline per week for a mean duration of 39 +/- 29 months underwent echocardiography. Abnormalities of the cardiac valves were present in 3 patients (7%): 1 patient exhibited mild mitral regurgitation, 1 patient had focal aortic valve thickening, and 1 patient demonstrated mitral valve thickening. We found no significant difference in either the cumulative dose of cabergoline (P = .800) or the duration of cabergoline therapy (P = .745) between those patients with and those without these echocardiographic abnormalities. CONCLUSION We found echocardiographic valve abnormalities in 3 of 45 patients (7%) who had been prescribed cabergoline for the management of hyperprolactinemia. This prevalence of valvular heart disease after approximately 3 years of cabergoline treatment is no different from that previously reported in normal populations as determined by echocardiography.

Suprasellar Rathke cleft cysts: clinical presentation and treatment outcomes.

BACKGROUND Rathke cleft cysts (RCCs), benign remnants of the Rathke pouch typically arising in the sella, sometimes have suprasellar extension. Purely suprasellar RCCs are rarely reported. OBJECTIVE To compare the presentations, surgical outcomes, and pathology of purely suprasellar RCCs and sellar-based RCCs. METHODS We retrospectively reviewed records, magnetic resonance images, laboratory results, and pathology of 151 RCC patients surgically managed at our institution from 1989 to 2009. The RCCs were classified as purely sellar (type I, n = 76), sellar with suprasellar extension (type II, n = 56), or purely suprasellar (type III, n = 19). RESULTS The RCCs with a suprasellar component (types II and III) more commonly presented with visual dysfunction (P < .001). Complete cyst drainage occurred in 89%, 55%, and 38% of type I, II, and III RCCs, respectively (P < .001). Vision improved in 100%, 55%, and 33% and headache improved in 74%, 64%, and 29% of type I, II, and III patients, respectively (P = .02). Temporary or permanent postoperative diabetes insipidus occurred in 5%, 16%, and 21% of type I, II, and III patients, respectively. (P < .001). In a multivariate analysis, RCC type was the only factor predicting recurrence. Kaplan-Meier 3-year recurrence/progression rates were 0%, 16%, and 29% for type I, II, and III RCCs, respectively (P < .001, type I vs II, type I vs III; P = .5 type II vs III). CONCLUSION The RCCs with a suprasellar component are neurosurgically challenging because of their proximity to the optic chiasm and infundibulum. Compared with sellar-based RCCs, RCCs with a suprasellar component more frequently present with visual dysfunction, are more difficult to completely eliminate, recur more frequently, and are associated with higher postoperative endocrine morbidity, and their preoperative visual dysfunction and headache less frequently improve with surgery. These factors must be considered during the treatment of RCCs with a suprasellar component. ABBREVIATIONS RCC: Rathke cleft cyst

A comprehensive long-term retrospective analysis of silent corticotrophic adenomas vs hormone-negative adenomas.

BACKGROUND Silent corticotrophic adenomas (SCAs) stain adrenocorticotropic hormone (ACTH)+ without causing Cushing disease. SCAs are reportedly more aggressive, but information comes from small series. OBJECTIVE To determine whether SCAs behave more aggressively than hormone-negative adenomas (HNAs), and characterize SCA ACTH production alterations. METHODS SCAs (n = 75) and HNAs (n = 1726) diagnosed at our institution from 1990 to 2011 were retrospectively reviewed. RT-PCR was used to compare expression of ACTH-producing factors. RESULTS SCA patients exhibited comparable sex and age as HNA patients (P = .7-.9). SCAs exhibited comparable size as HNAs (2.2 vs 2.0 cm, P = .2), with cavernous sinus invasion in 30% of SCAs vs 18% of HNAs (P = .03). SCA patients had higher mean preoperative serum ACTH (46 vs 19 ng/L; P = .005; normal = 5-27 ng/L), but comparable serum cortisol (13 vs 12 μg/dL; normal = 4-22 μg/dL; P < .05) as HNA patients. SCAs were gross totally resected 59% of the time, vs 53% for HNAs (P = .8). Kaplan-Meier 3-year progression/recurrence rates were 34% for strongly ACTH-positive Type I SCAs, 10% for weakly ACTH-positive Type II SCAs, and 6% for HNAs (P < .001 SCA vs HNA; P < .001 Type I vs HNA; and P = .08 Type II vs HNA). Expression of ACTH precursor pro-opiomelanocortin was 900-fold elevated in SCAs and 1300-fold elevated in Cushing disease-causing adenomas (CDCAs) vs HNAs (P < .001). Transcription of PC1/3, which cleaves pro-opiomelanocortin into ACTH, was 30-fold higher in CDCAs than SCAs (P = .02). CONCLUSION In the largest series to date, SCAs exhibited comparable size, but increased cavernous sinus invasion and progression/recurrence vs HNAs. SCAs exhibit deficient pro-opiomelanocortin to ACTH conversion. Close follow-up is warranted for SCAs.

Rathke cleft cysts in pediatric patients: presentation, surgical management, and postoperative outcomes

OBJECT Rathke cleft cysts (RCC) are benign sellar lesions most often found in adults, and more infrequently in children. They are generally asymptomatic but sometimes require surgical treatment through a transsphenoidal corridor. The purpose of this study was to compare adult versus pediatric cases of RCC. METHODS The authors retrospectively reviewed presenting symptoms, MR imaging findings, laboratory study results, and pathological findings in 147 adult and 14 pediatric patients who underwent surgery for treatment of RCCs at the University of Californial at San Francisco between 1996 and 2008. RESULTS In both the adult and pediatric groups, most patients were female (78% of adults, 79% of pediatric patients, p = 0.9). Headache was the most common symptom in both groups (reported by 50% of pediatric patients and 33% of adults, p = 0.2). Preoperative hypopituitarism occurred in 41% of adults and 45% of pediatric patients (p = 0.8). Growth delay, a uniquely pediatric finding, was a presenting sign in 29% of pediatric patients. Visual complaints were a presenting symptom in 16% of adult and 7% of pediatric patients (p = 0.4). There was no difference between median cyst size in adults versus pediatric patients (1.2 cm in both, p = 0.7). Temporary or permanent postoperative diabetes insipidus occurred in 12% of adults and 21% of pediatric patients (p = 0.4). Kaplan-Meier analysis revealed an 8% RCC recurrence rate at 2 years for each group (p = 0.5). CONCLUSIONS The incidence of RCCs is much lower in the pediatric population; however, symptoms, imaging findings, and outcomes are similar, suggesting that pediatric RCCs arise from growth of remnants of the embryonic Rathke pouch earlier in life than adult RCCs but do not differ in any other way. It is important to consider RCCs in the differential diagnosis when pediatric patients present with visual impairment, unexplained headache, or hypopituitarism including growth delay. Although the average RCC size was similar in our pediatric and adult patient groups, the smaller size of the pituitary gland in pediatric patients suggests an increased relative RCC size.

The utility of external beam radiation and intracystic 32P radiation in the treatment of craniopharyngiomas.

AbstractBackground. The management of craniopharyngiomas has historically been controversial in terms of the extent of initial surgical resection and the use of additional treatments. Various options include radical excision versus a more conservative surgical approach followed by external beam radiation; most recently, intracystic 32P radiation has been used in selected patients. Methods. We reviewed our experience with 25 patients with craniopharyngiomas treated between 1984 and 1999 to assess the effectiveness of external beam radiation and intracystic 32P radiation therapy in preventing progression and recurrence of local disease. Results. All patients underwent surgery as a component of initial therapy for their histologically-proven craniopharyngiomas. Fifteen patients additionally received external beam radiation. Forty-five percent of patients who underwent incomplete resections followed by external beam radiation required additional therapy. In contrast, 80% of patients who had incomplete resections without post-operative external beam radiation required further treatment. Seven patients had intracystic 32P colloid injections. Neither of the two patients receiving 32P intracystic radiation as part of their initial therapy needed further treatment. Only one of the five patients receiving 32P intracavitary radiation for disease progression following initial therapy required further intervention. Of the remaining four patients, three enjoyed responses to treatment and one had stable disease. Conclusions. Our observations support the use of external beam radiation for prevention of tumor progression in adults unable to receive a complete surgical resection. Our results additionally suggest that intracystic 32P radiation results in control of cystic components of craniopharyngiomas in the majority of cases.

Utility of the immediate postoperative cortisol concentrations in patients with Cushing's disease.

BACKGROUNDSeveral investigators have recommended serial measurements of serum cortisol in the days following pituitary surgery to identify patients at risk of recurrence. OBJECTIVEWe systematically reviewed the literature on this topic and analyzed the usefulness of this test in our own patient population. METHODSWe identified studies publishing data regarding recurrence rates after transsphenoidal surgery for Cushings disease, focusing on studies with data regarding patients with early postoperative cortisol levels. We determined a cumulative relative risk of having a subnormal vs normal cortisol level postoperatively using a fixed-effects meta-analysis model. Additionally, we analyzed our own patients with Cushings disease undergoing transsphenoidal surgery and performed Kaplan-Meier analysis of recurrence-free survival for patients with undetectable, subnormal but detectable, and normal immediate 8 AM serum cortisol levels. RESULTSFourteen studies met inclusion criteria. The length of follow-up varied between 32 and 115 months. The cumulative rate of recurrence in the group of patients with subnormal cortisol levels was 9% (95% confidence interval: 6%–12%). The cumulative rate of recurrence in the group with normal cortisol levels was 24% (95% confidence interval: 17%–31%). We analyzed 73 of our own patients and found similar recurrence rates in patients with subnormal vs normal early postoperative cortisol levels (4% vs 22%, χ2 test, P < .05). CONCLUSIONAlthough a subnormal early postoperative cortisol level is predictive of improved outcome after transsphenoidal surgery for Cushings disease, it is not analogous with cure, nor is a normal level completely predictive of future failure.

Low-dose growth hormone administration mobilizes endothelial progenitor cells in healthy adults

OBJECTIVE Endothelial progenitor cells (EPCs) mobilize from the bone marrow secondary to a stimulus and home to sites of injury, where they differentiate into endothelial cells and contribute to the repair of damaged vasculature. We hypothesized that growth hormone (GH) administration would increase the number of circulating EPCs in adults and thereby represent a mechanism to enhance vascular health. DESIGN A prospective trial of low-dose GH (0.03mg/kg/week for 4 weeks followed by 0.06mg/kg/week for a maximum of four additional weeks) in 10 healthy adults (6 males and 4 females; mean age 37 years, range 26-65). Primary outcomes measured included the number of circulating EPCs as assessed by colony-forming unit (CFU) assay and flow cytometry. Secondary outcomes included plasma measurements of known mediators of EPC mobilization and indices of nitric oxide (NO). Outcomes were measured at baseline and at study completion. RESULTS GH administration increased serum IGF-1 (143ng/mL [IQR 121-164] to 222 [IQR 194-244]; P=0.005). The increase in early-outgrowth EPCs (13 CFU per high-power field [IQR 6-24] to 19 [IQR 13-40]; P=0.005) correlated with the peak IGF-1 after adjustment for the baseline number of early-outgrowth EPCs (r=0.719 [95% CI 0.06, 0.93]; P=0.027). The number of late-outgrowth EPCs as well as CD34+, VEGFR2(KDR)+, and AC133+ cells did not significantly change. Other mediators of EPC mobilization were stable while plasma nitrite trended upwards (1.3micromol/L [IQR 0-2.5] to 3.7 [IQR 2.2-8.9]; P=0.052). CONCLUSIONS GH administration selectively augments the early-outgrowth EPC population in healthy individuals. These findings both support GH replacement in the setting of GH deficiency to maintain vascular integrity and have implications for the use of GH in future regenerative cell-based therapies. Furthermore, the decrease in EPCs observed with aging may in part be explained by the declining somatotropic axis, and thereby contribute to cardiovascular senescence.

Factors predicting postoperative hyponatremia and efficacy of hyponatremia management strategies after more than 1000 pituitary operations

OBJECT Syndrome of inappropriate antidiuretic hormone secretion-induced hyponatremia is a common morbidity after pituitary surgery that can be profoundly symptomatic and cause costly readmissions. The authors calculated the frequency of postoperative hyponatremia after 1045 consecutive operations and determined the efficacy of interventions correcting hyponatremia. METHODS The authors performed a retrospective review of 1045 consecutive pituitary surgeries in the first 946 patients treated since forming a dedicated pituitary center 5 years ago. Patients underwent preoperative and daily inpatient sodium checks, with outpatient checks as needed. RESULTS Thirty-two patients presented with hyponatremia; 41% of these patients were symptomatic. Postoperative hyponatremia occurred after 165 operations (16%) a mean of 4 days after surgery (range 0-28 days); 19% of operations leading to postoperative hyponatremia were associated with postoperative symptoms (38% involved dizziness and 29% involved nausea/vomiting) and 15% involved readmission for a mean of 5 days (range 1-20 days). In a multivariate analysis including lesion size, age, sex, number of prior pituitary surgeries, surgical approach, pathology, lesion location, and preoperative hypopituitarism, only preoperative hypopituitarism predicted postoperative hyponatremia (p = 0.006). Of patients with preoperative hyponatremia, 59% underwent medical correction preoperatively and 56% had persistent postoperative hyponatremia. The mean correction rates were 0.4 mEq/L/hr (no treatment; n = 112), 0.5 mEq/L/hr (free water restriction; n = 24), 0.7 mEq/L/hr (salt tablets; n = 14), 0.3 mEq/L/hr (3% saline; n = 20), 0.7 mEq/L/hr (intravenous vasopressin receptor antagonist Vaprisol; n = 22), and 1.2 mEq/L/hr (oral vasopressin receptor antagonist tolvaptan; n = 9) (p = 0.002, ANOVA). While some patients received more than 1 treatment, correction rates were only recorded when a treatment was given alone. CONCLUSIONS After 1045 pituitary operations, postoperative hyponatremia was associated exclusively with preoperative hypopituitarism and was most efficiently managed with oral tolvaptan, with several interventions insignificantly different from no treatment. Promptly identifying hyponatremia in high-risk patients and management with agents like tolvaptan can improve safety and decrease readmission. For readmitted patients with severely symptomatic hyponatremia, the intravenous vasopressin receptor antagonist Vaprisol is another treatment option.

Microscopic endonasal transsphenoidal pituitary adenomectomy in the pediatric population: Clinical article

OBJECT Pituitary adenomas are uncommon in childhood. Although medical treatment can be effective in treating prolactinomas and some growth hormone (GH)-secreting tumors, resection is indicated when visual function is affected or the side effects of medical therapy are intolerable. The authors of this report describe their 10-year experience in managing pituitary adenomas via the microscopic endonasal transsphenoidal approach in a pediatric population. METHODS They performed a retrospective review of a surgical case series based at a single institution and consisting of 34 consecutive pediatric patients with endocrine-active (32 patients) and endocrine-inactive (2 patients) adenomas. These patients were surgically treated via an endonasal transsphenoidal approach between 1999 and 2008. Patient charts were reviewed, and clinical data were compiled and analyzed using the chi-square and Kaplan-Meier tests. RESULTS The patient cohort consisted of 20 girls and 14 boys, with ages ranging from 9 to 18 years and a median age of 16 years. Thirty-two patients (94%) underwent surgery for endocrine-active tumors, including 10 (29%) with Cushing disease, 21 (62%) with prolactinomas, and 1 (3%) with GH-secreting tumors. Two patients with nonsecreting adenomas underwent surgery for apoplexy. The mean tumor volume was 5.4 cm(3), and 13 patients (38%) had suprasellar extension and 7 (21%) had cavernous sinus invasion. Gross-total resection was achieved in 26 patients (76%), although it was significantly less likely to be achieved in the setting of cavernous sinus invasion (p < 0.001) but was unaffected by suprasellar extension. Residual tumor was treated with radiation therapy in 6 patients (18%). The average duration of hospital stay was 1.6 days. The median follow-up time was 18 months. After surgery, 19 patients (56%) had normal hormone function without adjuvant therapy, 8 (24%) had normal function with adjuvant therapy, and 5 (15%) had persistently elevated hormone levels. Patients with a macroprolactinoma were significantly more likely to require postoperative adjuvant therapy than were those with a microprolactinoma (p < 0.03). CONCLUSIONS Endonasal transsphenoidal resection is a safe, well-tolerated, and potentially curative treatment option for pituitary adenomas in children. Despite the technical challenges associated with this approach in the pediatric population, these tumors can be effectively managed with minimal morbidity. Endocrine function is usually preserved, and the majority of patients will not require lifelong medical therapy.