Diagnosis and management of prolactin-secreting pituitary adenomas: a Pituitary Society international Consensus Statement.

This Consensus Statement from an international, multidisciplinary workshop sponsored by the Pituitary Society offers evidence-based graded consensus recommendations and key summary points for clinical practice on the diagnosis and management of prolactinomas. Epidemiology and pathogenesis, clinical presentation of disordered pituitary hormone secretion, assessment of hyperprolactinaemia and biochemical evaluation, optimal use of imaging strategies and disease-related complications are addressed. In-depth discussions present the latest evidence on treatment of prolactinoma, including efficacy, adverse effects and options for withdrawal of dopamine agonist therapy, as well as indications for surgery, preoperative medical therapy and radiation therapy. Management of prolactinoma in special situations is discussed, including cystic lesions, mixed growth hormone-secreting and prolactin-secreting adenomas and giant and aggressive prolactinomas. Furthermore, considerations for pregnancy and fertility are outlined, as well as management of prolactinomas in children and adolescents, patients with an underlying psychiatric disorder, postmenopausal women, transgender individuals and patients with chronic kidney disease. The workshop concluded that, although treatment resistance is rare, there is a need for additional therapeutic options to address clinical challenges in treating these patients and a need to facilitate international registries to enable risk stratification and optimization of therapeutic strategies.

Ectopic lipid metabolism in anterior pituitary dysfunction.

Over the past decades, adapted lifestyle and dietary habits in industrialized countries have led to a progress of obesity and associated metabolic disorders. Concomitant insulin resistance and derangements in lipid metabolism foster the deposition of excess lipids in organs and tissues with limited capacity of physiologic lipid storage. In organs pivotal for systemic metabolic homeostasis, this ectopic lipid content disturbs metabolic action, thereby promotes the progression of metabolic disease, and inherits a risk for cardiometabolic complications. Pituitary hormone syndromes are commonly associated with metabolic diseases. However, the impact on subcutaneous, visceral, and ectopic fat stores between disorders and their underlying hormonal axes is rather different, and the underlying pathophysiological pathways remain largely unknown. Pituitary disorders might influence ectopic lipid deposition indirectly by modulating lipid metabolism and insulin sensitivity, but also directly by organ specific hormonal effects on energy metabolism. In this review, we aim to I) provide information about the impact of pituitary disorders on ectopic fat stores, II) and to present up-to-date knowledge on potential pathophysiological mechanisms of hormone action in ectopic lipid metabolism.

Outcome of CRH stimulation test and overnight 8 mg dexamethasone suppression test in 469 patients with ACTH-dependent Cushing's syndrome.

Objective: To evaluate diagnostic accuracy of the corticotropin-releasing hormone (CRH) stimulation test and the overnight 8 mg dexamethasone suppression test (DST) for the differentiation of Cushing's disease (CD) and ectopic Cushing's syndrome (ECS). Methods: Retrospective study in 6 European centers. Inclusion criteria: patients with a) overt adrenocorticotropin (ACTH)-dependent Cushing's syndrome at the time of dynamic testing, b) histopathological confirmed tumors and/or c) postoperative biochemical remission and/or adrenal insufficiency. Optimal cut-offs were calculated via receiver operating characteristic (ROC) analysis using CD as reference. Results: 469 patients were analyzed [78% females; median age 43 years (IQR 19)]. CRH test and overnight 8 mg DST were performed in 420 [CD, n=394 (94%); ECS, n=26 (6%)] and 237 patients [228 CD (96%), 9 ECS (4%)]. Both tests were performed in 205 patients (44%). The post-CRH %-increase at 30 minutes of both ACTH (cut-off ≥31%, sensitivity 83%, specificity 85%, AUC 0.81) and cortisol (cut-off ≥12%, sensitivity 82%, specificity 89%, AUC 0.86) discriminated best between CD and ECS. A test duration of >60 minutes did not improve diagnostic performance of the CRH test. The optimal cortisol cut-off for the %-suppression during the 8 mg DST was ≥55% (sensitivity 80%, specificity 78%, AUC 0.75). Conclusion: The CRH test has equivalent sensitivity but higher specificity than the 8 mg DST and is therefore the test of first choice. The diagnostic outcome of ACTH and cortisol is well comparable, however, sampling beyond 60 minutes post-CRH does not provide diagnostic benefits.

Diagnostic criteria of small sellar lesions with hyperprolactinemia: Prolactinoma or else.

Objective: To evaluate the combined predictive value of MRI criteria with the prolactin-volume-ratio (PVR) to differentiate prolactinoma from non-prolactinoma, in small sellar lesions with hyperprolactinemia. Methods: Retrospective analysis of 55 patients with sellar lesions of ≤15 mm diameter on MRI and hyperprolactinemia of ≤150 ng/mL, surgically treated between 2003 and 2020 at the Medical University of Vienna, with a conclusive histopathological report. Serum prolactin levels, extent of pituitary stalk deviation, size and volume of the lesion were assessed. The PVR was calculated by dividing the preoperative prolactin level by tumor volume. Results: Our study population consisted of 39 patients (71%) with a prolactin-producing pituitary adenoma (group A), while 16 patients (29%) had another type of sellar lesion (group B). Patients in group A were significantly younger (p=0.012), had significantly higher prolactin levels at diagnosis (p<0.001) as well as smaller tumor volume (p=0.036) and lower degree of pituitary stalk deviation (p=0.009). The median PVR was significantly higher in group A (243 ng/mL per cm3) than in group B (83 ng/mL per cm3; p=0.002). Furthermore, the regression operating characteristics analysis revealed a PVR >100 ng/mL per cm3 to be predictive for distinguishing prolactin-producing lesions from other small sellar lesions. Conclusion: In patients with small sellar lesions, Prolactin-Volume-Ratios >100 represents a possible predictive marker for the diagnosis of prolactin-producing pituitary adenomas.

Impact of Tafamidis and Optimal Background Treatment on Physical Performance in Patients With Transthyretin Amyloid Cardiomyopathy.

BACKGROUND: In patients with transthyretin amyloid cardiomyopathy, tafamidis was shown to slow the decline in 6-minute walking distance as compared with placebo. We aimed to define the impact of tafamidis and optimal background treatment on functional capacity as determined by cardiopulmonary exercise testing (CPET). METHODS: Seventy-eight consecutive patients were enrolled in the study. They underwent CPET at baseline, and outcome defined as death or heart failure hospitalization was obtained for a time period of up to 30 months. Fifty-four patients completed a follow-up CPET at 9±3 months (range, 4-16 months). Improvement in peak VO2 at follow-up was defined as ∆peak VO2≥1.0 mL/(kg·min), stable peak VO2 was defined as 0≤∆peak VO2<1.0 mL/(kg·min), and decline in peak VO2 was defined by ∆peak VO2<0 mL/(kg·min). RESULTS: Baseline peak VO2>14 mL/(kg·min) as well as minute ventilation/carbon dioxide production slope≤34 were associated with a lower risk of death or heart failure hospitalization (P=0.002, P=0.007, respectively). In 54 patients, who received tafamidis and underwent repeat CPET testing, an improvement in physical performance (P=0.002) was observed at follow-up. When comparing pre and post-treatment parameters, 29 patients (54%) showed an increase in percent predicted peak VO2 (P<0.0001), an improvement of peak VO2 (P<0.0001), and better physical performance at follow-up (P<0.0001). Patients with stable or improved peak VO2 had less advanced heart disease at baseline (P=0.046). CONCLUSIONS: Our findings demonstrate that baseline peak VO2 and baseline minute ventilation/carbon dioxide production slope predict outcomes and an improvement in physical performance as measured by CPET was observed in patients receiving tafamidis, who had less advanced disease at baseline, emphasizing the importance of early diagnosis.

Long-term Safety of Growth Hormone in Adults With Growth Hormone Deficiency: Overview of 15 809 GH-Treated Patients.

CONTEXT: Data on long-term safety of growth hormone (GH) replacement in adults with GH deficiency (GHD) are needed. OBJECTIVE: We aimed to evaluate the safety of GH in the full KIMS (Pfizer International Metabolic Database) cohort. METHODS: The worldwide, observational KIMS study included adults and adolescents with confirmed GHD. Patients were treated with GH (Genotropin [somatropin]; Pfizer, NY) and followed through routine clinical practice. Adverse events (AEs) and clinical characteristics (eg, lipid profile, glucose) were collected. RESULTS: A cohort of 15 809 GH-treated patients were analyzed (mean follow-up of 5.3 years). AEs were reported in 51.2% of patients (treatment-related in 18.8%). Crude AE rate was higher in patients who were older, had GHD due to pituitary/hypothalamic tumors, or adult-onset GHD. AE rate analysis adjusted for age, gender, etiology, and follow-up time showed no correlation with GH dose. A total of 606 deaths (3.8%) were reported (146 by neoplasms, 71 by cardiac/vascular disorders, 48 by cerebrovascular disorders). Overall, de novo cancer incidence was comparable to that in the general population (standard incidence ratio 0.92; 95% CI, 0.83-1.01). De novo cancer risk was significantly lower in patients with idiopathic/congenital GHD (0.64; 0.43-0.91), but similar in those with pituitary/hypothalamic tumors or other etiologies versus the general population. Neither adult-onset nor childhood-onset GHD was associated with increased de novo cancer risks. Neutral effects were observed in lipids/fasting blood glucose levels. CONCLUSION: These final KIMS cohort data support the safety of long-term GH replacement in adults with GHD as prescribed in routine clinical practice.

Perioperative Management of a Patient With Cushing Disease.

Patients with Cushing disease (CD) may present with both chronic and acute perioperative complications that necessitate multidisciplinary care. This review highlights several objectives for these patients before and after transsphenoidal surgery. Preoperative management includes treatment of electrolyte disturbances, cardiovascular comorbidities, prediabetes/diabetes, as well as prophylactic consideration(s) for thromboembolism and infection(s). Preoperative medical therapy (PMT) could prove beneficial in patients with severe hypercortisolism or in cases of delayed surgery. Some centers use PMT routinely, although the clinical benefit for all patients is controversial. In this setting, steroidogenesis inhibitors are preferred because of rapid and potent inhibition of cortisol secretion. If glucocorticoids (GCs) are not used perioperatively, an immediate remission assessment postoperatively is possible. However, perioperative GC replacement is sometimes necessary for clinically unstable or medically pretreated patients and for those patients with surgical complications. A nadir serum cortisol of less than 2 to 5µg/dL during 24 to 74 hours postoperatively is generally accepted as remission; higher values suggest nonremission, while a few patients may display delayed remission. If remission is not achieved, additional treatments are pursued. The early postoperative period necessitates multidisciplinary awareness for early diagnosis of adrenal insufficiency (AI) to avoid adrenal crisis, which may also be potentiated by acute postoperative complications. Preferred GC replacement is hydrocortisone, if available. Assessment of recovery from postoperative AI should be undertaken periodically. Other postoperative targets include decreasing antihypertensive/diabetic therapy if in remission, thromboprophylaxis, infection prevention/treatment, and management of electrolyte disturbances and/or potential pituitary deficiencies. Evaluation of recovery of thyroid, gonadal, and growth hormone deficiencies should also be performed during the following months postoperatively.

Diagnosis of Pituitary Adenoma Biopsies by Ultrahigh Resolution Optical Coherence Tomography Using Neuronal Networks.

Objective: Despite advancements of intraoperative visualization, the difficulty to visually distinguish adenoma from adjacent pituitary gland due to textural similarities may lead to incomplete adenoma resection or impairment of pituitary function. The aim of this study was to investigate optical coherence tomography (OCT) imaging in combination with a convolutional neural network (CNN) for objectively identify pituitary adenoma tissue in an ex vivo setting. Methods: A prospective study was conducted to train and test a CNN algorithm to identify pituitary adenoma tissue in OCT images of adenoma and adjacent pituitary gland samples. From each sample, 500 slices of adjacent cross-sectional OCT images were used for CNN classification. Results: OCT data acquisition was feasible in 19/20 (95%) patients. The 16.000 OCT slices of 16/19 of cases were employed for creating a trained CNN algorithm (70% for training, 15% for validating the classifier). Thereafter, the classifier was tested on the paired samples of three patients (3.000 slices). The CNN correctly predicted adenoma in the 3 adenoma samples (98%, 100% and 84% respectively), and correctly predicted gland and transition zone in the 3 samples from the adjacent pituitary gland. Conclusion: Trained convolutional neural network computing has the potential for fast and objective identification of pituitary adenoma tissue in OCT images with high sensitivity ex vivo. However, further investigation with larger number of samples is required.

Consensus on diagnosis and management of Cushing's disease: a guideline update.

Cushing's disease requires accurate diagnosis, careful treatment selection, and long-term management to optimise patient outcomes. The Pituitary Society convened a consensus workshop comprising more than 50 academic researchers and clinical experts to discuss the application of recent evidence to clinical practice. In advance of the virtual meeting, data from 2015 to present about screening and diagnosis; surgery, medical, and radiation therapy; and disease-related and treatment-related complications of Cushing's disease summarised in recorded lectures were reviewed by all participants. During the meeting, concise summaries of the recorded lectures were presented, followed by small group breakout discussions. Consensus opinions from each group were collated into a draft document, which was reviewed and approved by all participants. Recommendations regarding use of laboratory tests, imaging, and treatment options are presented, along with algorithms for diagnosis of Cushing's syndrome and management of Cushing's disease. Topics considered most important to address in future research are also identified.

Morpho-Molecular Metabolic Analysis and Classification of Human Pituitary Gland and Adenoma Biopsies Based on Multimodal Optical Imaging.

Pituitary adenomas count among the most common intracranial tumors. During pituitary oncogenesis structural, textural, metabolic and molecular changes occur which can be revealed with our integrated ultrahigh-resolution multimodal imaging approach including optical coherence tomography (OCT), multiphoton microscopy (MPM) and line scan Raman microspectroscopy (LSRM) on an unprecedented cellular level in a label-free manner. We investigated 5 pituitary gland and 25 adenoma biopsies, including lactotroph, null cell, gonadotroph, somatotroph and mammosomatotroph as well as corticotroph. First-level binary classification for discrimination of pituitary gland and adenomas was performed by feature extraction via radiomic analysis on OCT and MPM images and achieved an accuracy of 88%. Second-level multi-class classification was performed based on molecular analysis of the specimen via LSRM to discriminate pituitary adenomas subtypes with accuracies of up to 99%. Chemical compounds such as lipids, proteins, collagen, DNA and carotenoids and their relation could be identified as relevant biomarkers, and their spatial distribution visualized to provide deeper insight into the chemical properties of pituitary adenomas. Thereby, the aim of the current work was to assess a unique label-free and non-invasive multimodal optical imaging platform for pituitary tissue imaging and to perform a multiparametric morpho-molecular metabolic analysis and classification.

The Interaction of Insulin and Pituitary Hormone Syndromes.

Pituitary hormone axes modulate glucose metabolism and exert direct or indirect effects on insulin secretion and function. Cortisol and growth hormone are potent insulin-antagonistic hormones. Therefore impaired glucose tolerance, elevated fasting glucose concentrations and diabetes mellitus are frequent in Cushing's disease and acromegaly. Also prolactinomas, growth hormone (GH) deficiency, hypogonadism and hypothyroidism might be associated with impaired glucose homeostasis but usually to a lesser extent. Therefore glucose metabolism needs to be closely monitored and treated in patients with pituitary adenomas. Correction of the pituitary dysfunction is frequently followed by improvement of glucose homeostasis.

MANAGEMENT OF ENDOCRINE DISEASE: Cardiovascular risk assessment, thromboembolism, and infection prevention in Cushing's syndrome: a practical approach.

Cushing's syndrome (CS) is associated with increased mortality that is driven by cardiovascular, thromboembolic, and infection complications. Although these events are expected to decrease during disease remission, incidence often transiently increases postoperatively and is not completely normalized in the long-term. It is important to diagnose and treat cardiovascular, thromboembolic, and infection complications concomitantly with CS treatment. Management of hyperglycemia/diabetes, hypertension, hypokalemia, hyperlipidemia, and other cardiovascular risk factors is generally undertaken in accordance with clinical care standards. Medical therapy for CS may be needed even prior to surgery in severe and/or prolonged hypercortisolism, and treatment adjustments can be made based on disease pathophysiology and drug-drug interactions. Thromboprophylaxis should be considered for CS patients with severe hypercortisolism and/or postoperatively, based on individual risk factors of thromboembolism and bleeding. Pneumocystis jiroveci pneumonia prophylaxis should be considered for patients with high urinary free cortisol at the initiation of hypercortisolism treatment.

Acute and Life-threatening Complications in Cushing Syndrome: Prevalence, Predictors, and Mortality.

CONTEXT: Cushing syndrome (CS) results in significant morbidity and mortality. OBJECTIVE: To study acute and life-threatening complications in patients with active CS. METHODS: We performed a retrospective cohort study using inpatient and outpatient records of patients with CS in a tertiary center. A total of 242 patients with CS were included, including 213 with benign CS (pituitary n = 101, adrenal n = 99, ectopic n = 13), and 29 with malignant disease. We collected acute complications necessitating hospitalization, from appearance of first symptoms of hypercortisolism until 1 year after biochemical remission. Mortality data were obtained from the national registry. Baseline factors relating to and predicting acute complications were tested using uni- and multivariate analysis. RESULTS: The prevalence of acute complications was 62% in patients with benign pituitary CS, 40% in patients with benign adrenal CS, and 100% in patients with ectopic CS. Complications observed in patients with benign CS included infections (25%), thromboembolic events (17%), hypokalemia (13%), hypertensive crises (9%), cardiac arrhythmias (5%), and acute coronary events (3%). Among these patients, 23% had already been hospitalized for acute complications before CS was suspected, and half of complications occurred after the first surgery. Glycated hemoglobin (HbA1c) and 24-hour urinary free cortisol positively correlated with the number of acute complications per patient. Patients with malignant disease had significantly higher rates of acute complications. Mortality during the observation period was 2.8% and 59% in benign and malignant CS, respectively. CONCLUSIONS: This analysis highlights the whole spectrum of acute and life-threatening complications in CS, and their high prevalence even before disease diagnosis and after successful surgery.

Expression of additional transcription factors is of prognostic value for aggressive behavior of pituitary adenomas.

OBJECTIVE: According to the latest WHO classification of tumors of endocrine organs in 2017, plurihormonal adenomas are subclassified by their transcription factor (TF) expression. In the group of plurihormonal adenomas with unusual immunohistochemical combinations (PAWUC), the authors identified a large fraction of adenomas expressing TFs for gonadotroph adenoma (TFGA) cells in addition to other TFs. The aim of this study was to compare clinicopathological parameters of PAWUC with TFGA expression to gonadotroph adenomas that only express TFGA. METHODS: This retrospective single-center series comprises 73 patients with TFGA-positive pituitary adenomas (SF1, GATA3, estrogen receptor α): 22 PAWUC with TFGA (TFGA-plus group) and 51 with TFGA expression only (TFGA-only group). Patient characteristics, outcome parameters, rate of invasiveness (assessed by direct endoscopic inspection), and MIB1 and MGMT status were compared between groups. RESULTS: Patients in the TFGA-plus group were significantly younger than patients in the TFGA-only group (age 46 vs 56 years, respectively; p = 0.007). In the TFGA-only group, pituitary adenomas were significantly larger (diameter 25 vs 18.3 mm, p = 0.002). Intraoperatively, signs of invasiveness were significantly more common in the TFGA-plus group than in the TFGA-only group (50% vs 16%, p = 0.002). Gross-total resection was significantly lower in the nonfunctioning TFGA-plus group than in the TFGA-only group (44% vs 86%, p = 0.004). MIB1 and MGMT status showed no significant difference between groups. CONCLUSIONS: These data suggest a more aggressive behavior of TFGA-positive adenomas if an additional TF is expressed within the tumor cells. Shorter radiographic surveillance and earlier consideration for retreatment should be recommended in these adenoma types.

Increased ATP synthesis might counteract hepatic lipid accumulation in acromegaly.

Patients with active acromegaly (ACRO) exhibit low hepatocellular lipids (HCL), despite pronounced insulin resistance (IR). This contrasts the strong association of IR with nonalcoholic fatty liver disease in the general population. Since low HCL levels in ACRO might be caused by changes in oxidative substrate metabolism, we investigated mitochondrial activity and plasma metabolomics/lipidomics in active ACRO. Fifteen subjects with ACRO and seventeen healthy controls, matched for age, BMI, sex, and body composition, underwent 31P/1H-7-T MR spectroscopy of the liver and skeletal muscle as well as plasma metabolomic profiling and an oral glucose tolerance test. Subjects with ACRO showed significantly lower HCL levels, but the ATP synthesis rate was significantly increased compared with that in controls. Furthermore, a decreased ratio of unsaturated-to-saturated intrahepatocellular fatty acids was found in subjects with ACRO. Within assessed plasma lipids, lipidomics, and metabolomics, decreased carnitine species also indicated increased mitochondrial activity. We therefore concluded that excess of growth hormone (GH) in humans counteracts HCL accumulation by increased hepatic ATP synthesis. This was accompanied by a decreased ratio of unsaturated-to-saturated lipids in hepatocytes and by a metabolomic profile, reflecting the increase in mitochondrial activity. Thus, these findings help to better understanding of GH-regulated antisteatotic pathways and provide a better insight into potentially novel therapeutic targets for treating NAFLD.

Ectopic Cushing's syndrome in a patient with inferior petrosal sinus sampling indicating pituitary-dependent ACTH secretion.

In an unclear case of Cushing's syndrome, IPSS identifies the origin of ACTH secretion, and together with MRI enables the localization of an ectopic corticotroph adenoma in the parasellar or cavernous sinuses region.

Fertility and Pregnancy in Women With Hypopituitarism: A Systematic Literature Review.

CONTEXT: Human reproduction is mainly governed from the hypothalamic-adrenal-gonadal (HPG) axis, which controls both ovarian morphology and function. Disturbances in the secretion of other anterior pituitary hormones (and their respective endocrine axes) interfere with HPG activity and have been linked to fertility problems. In normal pregnancy, maintenance of homeostasis is associated with continuous changes in pituitary morphology and function, which need to be considered during hormone replacement in patients with hypopituitarism. DESIGN: We conducted a systematic PubMed literature review from 1969 to 2019, with the following keywords: fertility and hypopituitarism, pregnancy and hypopituitarism, and ovulation induction and hypopituitarism. Case reports or single-case series of up to 2 patients/4 pregnancies were excluded. RESULTS: Eleven publications described data on fertility (n = 6) and/or pregnancy (n = 7) in women with hypopituitarism. Women with hypopituitarism often need assisted reproductive treatment, with pregnancy rates ranging from 47% to 100%. In patients achieving pregnancy, live birth rate ranged from 61% to 100%. While glucocorticoids, levothyroxine, and desmopressin are safely prescribed during pregnancy, growth hormone treatment regimens vary significantly between countries, and several publications support a positive effect in women seeking fertility. CONCLUSIONS: In this first systematic review on fertility, ovulation induction, and pregnancy in patients with hypopituitarism, we show that while literature is scarce, birth rates are high in patients achieving pregnancy. However, prospective studies are needed for evaluating outcomes in relationship to treatment patterns. Replacement therapy in hypopituitarism should always mimic normal physiology, and this becomes challenging with changing demands during pregnancy evolution.

Efficacy of Temozolomide Therapy in Patients With Aggressive Pituitary Adenomas and Carcinomas-A German Survey.

CONTEXT: Despite growing evidence that temozolomide (TMZ) therapy is effective for the treatment of aggressive pituitary tumors (APTs) or carcinomas (PCs), individual therapy decisions remain challenging. OBJECTIVE: We therefore aimed to report on clinical characteristics leading to initiation of TMZ therapy and to add evidence on TMZ long-term effectiveness. DESIGN AND SUBJECTS: Retrospective survey on TMZ treatment in patients with APTs or PCs. TMZ therapy was initiated in 47 patients (22 females) with APTs (n = 34) or PCs (n = 13). Mean age at diagnosis was 45 ± 15 years. The immunohistochemical subtypes were corticotroph (n = 20), lactotroph (n = 18), and nonfunctioning (n = 9) tumors. TMZ therapy started 8 years after initial diagnosis using a standard regimen (median 6 cycles) for the majority of patients. RESULTS: Long-term radiological response to TMZ after a median follow-up of 32 months with 4 patients still on TMZ therapy was tumor regression for 9 (20%), stable disease for 8 (17%), and tumor progression for 29 patients (63%) (outcome data available for 46 patients). Progression occurred 16 months after initiation of TMZ. Median estimated progression-free survival was 23 months. Disease stabilization and median progression-free survival did not differ between patients with APTs or PCs. Predictors of tumor response were not identified. Overall, TMZ was well tolerated. CONCLUSION: We performed a nationwide survey on TMZ therapy in patients with APTs and PCs. While early response rates to TMZ are promising, long-term outcome is less favorable. Prolonged TMZ administration should be considered. We were not able to confirm previously reported predictors of tumor response to TMZ.

Line Scan Raman Microspectroscopy for Label-Free Diagnosis of Human Pituitary Biopsies.

Pituitary adenomas are neoplasia of the anterior pituitary gland and can be subdivided into hormone-producing tumors (lactotroph, corticotroph, gonadotroph, somatotroph, thyreotroph or plurihormonal) and hormone-inactive tumors (silent or null cell adenomas) based on their hormonal status. We therefore developed a line scan Raman microspectroscopy (LSRM) system to detect, discriminate and hyperspectrally visualize pituitary gland from pituitary adenomas based on molecular differences. By applying principal component analysis followed by a k-nearest neighbor algorithm, specific hormone states were identified and a clear discrimination between pituitary gland and various adenoma subtypes was achieved. The classifier yielded an accuracy of 95% for gland tissue and 84-99% for adenoma subtypes. With an overall accuracy of 92%, our LSRM system has proven its potential to differentiate pituitary gland from pituitary adenomas. LSRM images based on the presence of specific Raman bands were created, and such images provided additional insight into the spatial distribution of particular molecular compounds. Pathological states could be molecularly differentiated and characterized with texture analysis evaluating Grey Level Cooccurrence Matrices for each LSRM image, as well as correlation coefficients between LSRM images.