Medicine (St Vincent's) - Research Publications

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    OR32-06 Opportunistic Assessment of Pituitary Gland with Routine MRI and PET/CT Can Guide in Earlier and Increased Identification of Hypophysitis in Patients Treated with Combination Checkpoint Inhibitors
    Galligan, A ; Iravani, A ; Lasocki, A ; Wallace, R ; Weppler, A ; Au-Yeung, G ; Sachithanandan, N ; Chiang, CY ; Wentworth, J ; Colman, PG ; Kay, TW ; Krishnamurthy, B ; Sandhu, S ( 2020-05)
    Abstract Background: Hypophysitis is one of the commonly reported adverse events related to immune checkpoint inhibitors (ICI), and the incidence is expected to rise with increased use of combined programmed cell death protein 1 (PD1) and cytotoxic T lymphocyte associated protein 4 (CTLA4) blockade. The clinical diagnosis can be delayed due to non-specific symptoms. At our centre, subjects undergo periodic imaging to assess tumour response to ICI. We reviewed whether neuroimaging studies can guide us in the diagnosis of hypophysitis and whether early changes can be detected before the onset of the clinical syndrome. Methods: We retrospectively reviewed the medical charts, biochemistry, structural brain imaging and whole-body positron emission tomography (PET) with specific reference to hypophysitis in 162 patients treated with combination ICI at a tertiary melanoma referral centre. Suspected cases were identified based on meeting one or more of the following criteria: 1) A documented diagnosis of hypophysitis or pituitary dysfunction found on chart review, 2) A relative change in pituitary size or appearance from baseline on neuroimaging studies, or 3) An increase in pituitary maximum standardized uptake value (SUVmax) greater than 25% from baseline on 18F-FDG PET. Results: 58/162 patients (36%) met criteria for suspected hypophysitis. Only 4 patients were identified on routine screening of early morning cortisol. 14 patients presented with symptoms leading to biochemical work up. A further 40 patients were found to have suspicious imaging changes, 13 of which went on to receive a formal diagnosis of hypophysitis. Of the remaining 27 patients, 23 were receiving high dose glucocorticoids for concomitant immune related adverse events at the time of the abnormal imaging study.Conclusion: We report the highest incidence to date of suspected hypophysitis in cohort of patients treated with combination ICI. This study highlights the important role of structural and functional neuroimaging in the early recognition of hypophysitis. Imaging may also play a role when the clinical syndrome is masked by concurrent glucocorticoid use.
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    SUN-127 Diagnostic Challenges Associated with the Rising Incidence of Endocrine Toxicity in the Era of Combination Immunotherapy
    Galligan, A ; Iravani, A ; Lasocki, A ; Wallace, R ; Weppler, A ; Au-Yeung, G ; Sachithanandan, N ; Chiang, CY ; Wentworth, J ; Colman, PG ; Kay, TW ; Krishnamurthy, B ; Sandhu, S ( 2020-05)
    Abstract Background: Immune checkpoint blockade is now established as standard of care in several malignancies. Trials involving combined cytotoxic T lymphocyte associated protein 4 (CTLA4) and programmed cell death protein 1 (PD1) blockade demonstrate improved tumour responses in melanoma but at the cost of severe grade 3-4 immune related adverse events (irAEs) in 55%, and endocrine irAEs in up to 10% [1]. Immune-mediated damage to endocrine glands can be a diagnostic and management challenge. We aimed to review the incidence, biochemical evolution and imaging findings of endocrine toxicity related to combined anti CTLA-4 and anti-PD-1 therapy. Methods: We undertook a retrospective chart review of patients who received combined ipilimumab and nivolumab for metastatic melanoma at a tertiary referral centre between 2016-2019. We recorded onset and duration of abnormal biochemistry in endocrine irAEs, reviewed all available MRI images for pituitary size (mm) and appearance and 18-F FDG PET images for features of hypophysitis, thyroiditis and pancreatitis. Results: 162 patients received combination therapy. At least one irAE was recorded in 135 patients (83%), 100 (62%) required glucocorticoids, and 84 (52%) had an unplanned hospital presentation due to irAEs. Thyroiditis occurred in 50 (30.9%), with median time to onset of 30.9 days (range 1-234 days). 35 cases were identified with routine biochemistry performed every 4-6 weeks. TSH receptor antibody was measured in 13 patients and all were negative. 29 (58%) developed permanent hypothyroidism. Central cortisol deficiency was documented in 31 (19%) with a median time to diagnosis of 67.5 days (range 5-286). 4 cases were diagnosed on routine biochemistry and 14 presented with symptoms prompting investigation. 13 were diagnosed after routine neuroimaging demonstrated a pituitary abnormality, and a further 27 patients without the clinical syndrome had features of hypophysitis on neuroimaging. New onset diabetes occurred in 3 people, in which pancreatic inflammation on imaging was found in 2. A further 3/5 patients with an asymptomatic elevated lipase were found to have abnormal pancreatic imaging. In one patient with no features of endocrine or exocrine failure, there was a significant increase in FDG uptake and a subsequent loss of pancreatic volume. Conclusion: We report real world incidence of endocrine irAEs with combination immunotherapy. Routine biochemistry leads to the detection of some but not all cases. Early recognition and avoidance of unplanned presentations remains a challenge. Opportunistic assessment of endocrine gland appearance on routine imaging studies may provide useful early diagnostic information. Reference: Larkin J, Chiarion-Sileni V, Gonzalez R, Grob JJ, Cowey CL, Lao CD, et al. Combined nivolumab and ipilimumab or monotherapy in untreated melanoma. N Engl J Med. (2015) 1:23-34. 10.1056/NEJMoa1504030
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    OR32-06 Opportunistic Assessment of Pituitary Gland with Routine MRI and PET/CT Can Guide in Earlier and Increased Identification of Hypophysitis in Patients Treated with Combination Checkpoint Inhibitors
    Galligan, A ; Iravani, A ; Lasocki, A ; Wallace, R ; Weppler, A ; Au-Yeung, G ; Sachithanandan, N ; Chiang, CY ; Wentworth, J ; Colman, PG ; Kay, TW ; Krishnamurthy, B ; Sandhu, S (The Endocrine Society, 2020-05-08)
    Abstract Background: Hypophysitis is one of the commonly reported adverse events related to immune checkpoint inhibitors (ICI), and the incidence is expected to rise with increased use of combined programmed cell death protein 1 (PD1) and cytotoxic T lymphocyte associated protein 4 (CTLA4) blockade. The clinical diagnosis can be delayed due to non-specific symptoms. At our centre, subjects undergo periodic imaging to assess tumour response to ICI. We reviewed whether neuroimaging studies can guide us in the diagnosis of hypophysitis and whether early changes can be detected before the onset of the clinical syndrome. Methods: We retrospectively reviewed the medical charts, biochemistry, structural brain imaging and whole-body positron emission tomography (PET) with specific reference to hypophysitis in 162 patients treated with combination ICI at a tertiary melanoma referral centre. Suspected cases were identified based on meeting one or more of the following criteria: 1) A documented diagnosis of hypophysitis or pituitary dysfunction found on chart review, 2) A relative change in pituitary size or appearance from baseline on neuroimaging studies, or 3) An increase in pituitary maximum standardized uptake value (SUVmax) greater than 25% from baseline on 18F-FDG PET. Results: 58/162 patients (36%) met criteria for suspected hypophysitis. Only 4 patients were identified on routine screening of early morning cortisol. 14 patients presented with symptoms leading to biochemical work up. A further 40 patients were found to have suspicious imaging changes, 13 of which went on to receive a formal diagnosis of hypophysitis. Of the remaining 27 patients, 23 were receiving high dose glucocorticoids for concomitant immune related adverse events at the time of the abnormal imaging study.Conclusion: We report the highest incidence to date of suspected hypophysitis in cohort of patients treated with combination ICI. This study highlights the important role of structural and functional neuroimaging in the early recognition of hypophysitis. Imaging may also play a role when the clinical syndrome is masked by concurrent glucocorticoid use.
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    Estimated insulin sensitivity in Type 1 diabetes adults using clinical and research biomarkers
    Januszewski, AS ; Sachithanandan, N ; Ward, G ; Karschimkus, CS ; O'Neal, DN ; Jenkins, AJ (ELSEVIER IRELAND LTD, 2020-09)
    AIMS: Insulin resistance in people with type 1 diabetes (T1D) is associated with increased risk of chronic complications and death. The gold standard to quantify insulin sensitivity, a euglycaemic hyperinsulinaemic clamp, is not applicable to clinical practice. We have employed clamp studies to develop a panel of formulae to estimate insulin sensitivity in adults with T1D for use in clinical practice and trials. METHODS: Clamps were conducted in 28 adults with T1D, who were also characterised with 38 clinical and research biomarkers. Exhaustive search analysis was used to derive equations correlating with clamp-quantified glucose disposal rate (GDR), GDR/plasma insulin (M/I) and log10M/I. RESULTS: Measured insulin sensitivity correlated with BMI, WHR, HDL-C, adipokines and inflammation markers on univariate analysis. Exhaustive search analysis derived three formulae correlating with clamp-derived GDR and logM/I (p < 0.0001), accounting for ≈62% of their variability. A formula using gender, age, HDL-C, pulse pressure and WHR performed as well as those containing inflammation and adipokine measures. CONCLUSIONS: The performance of formulae using routinely available parameters with/without research biomarkers in clinical studies and trials, particularly related to future complications, relevant lifestyle interventions, insulin delivery modes and insulin sensitisers is merited.
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    Cytoreductive Surgery of the Primary Tumor in Metastatic Adrenocortical Carcinoma: Impact on Patients' Survival
    Srougi, V ; Bancos, I ; Daher, M ; Lee, JE ; Graham, PH ; Karam, JA ; Henriquez, A ; Mckenzie, TJ ; Sada, A ; Bourdeau, I ; Poirier, J ; Vaidya, A ; Abbondanza, T ; Kiernan, CM ; Rao, SN ; Hamidi, O ; Sachithanandan, N ; Hoff, AO ; Chambo, JL ; Almeida, MQ ; Habra, MA ; Fragoso, MCB (ENDOCRINE SOC, 2022-03-24)
    CONTEXT: The role of cytoreduction of adrenocortical carcinoma (ACC) remains poorly understood. OBJECTIVE: To analyze the impact of cytoreductive surgery of the primary tumor in patients with metastatic ACC. DESIGN AND SETTING: We performed a multicentric, retrospective paired cohort study comparing the overall survival (OS) in patients with metastatic ACC who were treated either with cytoreductive surgery (CR group) or without cytoreductive surgery (no-CR group) of the primary tumor. Data were retrieved from 9 referral centers in the American-Australian-Asian Adrenal Alliance collaborative research group. PATIENTS: Patients aged ≥18 years with metastatic ACC at initial presentation who were treated between January 1, 1995, and May 31, 2019. INTERVENTION: Performance (or not) of cytoreductive surgery of the primary tumor. MAIN OUTCOME AND MEASURES: A propensity score match was done using age and the number of organs with metastasis (≤2 or >2). The main outcome was OS, determined from the date of diagnosis until death or until last follow-up for living patients. RESULTS: Of 339 patients pooled, 239 were paired and included: 128 in the CR group and 111 in the no-CR group. The mean follow-up was 67 months. Patients in the no-CR group had greater risk of death than did patients in the CR group (hazard ratio [HR] = 3.18; 95% CI, 2.34-4.32). Independent predictors of survival included age (HR = 1.02; 95% CI, 1.00-1.03), hormone excess (HR = 2.56; 95% CI, 1.66-3.92), and local metastasis therapy (HR = 0.41; 95% CI, 0.47-0.65). CONCLUSION: Cytoreductive surgery of the primary tumor in patients with metastatic ACC is associated with prolonged survival.
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    Independent euglycaemic hyperinsulinaemic clamp studies validate clinically applicable formulae to estimate insulin sensitivity in people with type 1 diabetes
    Januszewski, AS ; Niedzwiecki, P ; Sachithanandan, N ; Ward, GM ; Karschimkus, CS ; O'Neal, DN ; Zozulinska-Ziolkiewicz, DA ; Uruska, AA ; Jenkins, AJ (ELSEVIER SCI LTD, 2023-01)
    BACKGROUND AND AIM: Low insulin sensitivity (IS) increases Type 1 diabetes (T1D) complication risk and can be estimated by simple formulae developed from complex euglycemic hyperinsulinaemic clamp studies. We aimed to validate these formulae using independent clamp data. METHODS: Clamps were performed in 104 T1D adults. Measured glucose disposal rate (GDR) was correlated with eGDR and eLog10 M/I calculated by five IS formulae. RESULTS: Correlations ranged between 0.23-0.40. Two IS formulae (by the authors), using age, sex, HDL-C, HbA1c, pulse pressure, BMI, and waist-hip-ratio had the highest correlation with measured GDR and the best performance in detecting low IS.
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    Independent euglycaemic hyperinsulinaemic clamp studies validate clinically applicable formulae to estimate insulin sensitivity in people with type 1 diabetes (vol 17, 102691, 2023)
    Januszewski, AS ; Niedzwiecki, P ; Sachithanandan, N ; Ward, GM ; Karschimkus, CS ; O'Neal, DN ; Zozulinska-Ziolkiewicz, DA ; Uruska, AA ; Jenkins, AJ (ELSEVIER SCI LTD, 2023-01)
    The authors regret that in the original article, on the second page, in the section with eGDR equations, variables “sex” and “hypertension” were missing categorical values indicators (“F = 0, M = 1”; “Yes = 1, No = 0”, respectively) required to calculate eGDR. It should be corrected by adding “F = 0, M = 1” in two instances and “Yes = 1, No = 0” in one instance. Also, please note that Miller at al. defined “hypertension” as BP ≥140/90mmHg or use of any anti-hypertensive (drug) treatment. The authors apologise for any inconvenience caused.
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    Imaging for assessment of cancer treatment response to immune checkpoint inhibitors can be complementary in identifying hypophysitis
    Galligan, A ; Iravani, A ; Lasocki, A ; Wallace, R ; Weppler, AM ; Sachithanandan, N ; Chiang, C ; Colman, PG ; Wentworth, J ; Spain, L ; Au-Yeung, G ; Lee, B ; Kay, TWH ; Hicks, RJ ; Sandhu, S ; Krishnamurthy, B (FRONTIERS MEDIA SA, 2023-11-29)
    INTRODUCTION: Hypophysitis is reported in 8.5%-14% of patients receiving combination immune checkpoint inhibition (cICI) but can be a diagnostic challenge. This study aimed to assess the role of routine diagnostic imaging performed during therapeutic monitoring of combination anti-CTLA-4/anti-PD-1 treatment in the identification of hypophysitis and the relationship of imaging findings to clinical diagnostic criteria. METHODS: This retrospective cohort study identified patients treated with cICI between January 2016 and January 2019 at a quaternary melanoma service. Medical records were reviewed to identify patients with a documented diagnosis of hypophysitis based on clinical criteria. Available structural brain imaging with magnetic resonance imaging (MRI) or computed tomography (CT) of the brain and 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography with computed tomography (FDG-PET/CT) were assessed retrospectively. The main radiological outcome measures were a relative change in pituitary size or FDG uptake temporally attributed to cICI. RESULTS: There were 162 patients (median age 60 years, 30% female) included. A total of 100 and 134 had serial CT/MRI of the brain and FDG-PET/CT, respectively. There were 31 patients who had a documented diagnosis of hypophysitis and an additional 20 who had isolated pituitary imaging findings. The pituitary gland enlargement was mild, and the largest absolute gland size was 13 mm, with a relative increase of 7 mm from baseline. There were no cases of optic chiasm compression. Pituitary enlargement and increased FDG uptake were universally transient. High-dose glucocorticoid treatment for concurrent irAEs prevented assessment of the pituitary-adrenal axis in 90% of patients with isolated imaging findings. CONCLUSION: Careful review of changes in pituitary characteristics on imaging performed for assessment of therapeutic response to iICI may lead to increased identification and more prompt management of cICI-induced hypophysitis.
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    Interactive Calculator to Estimate Insulin Sensitivity (IS) in Type 1 Diabetes
    Januszewski, AS ; Niedzwiecki, P ; Sachithanandan, N ; Ward, GM ; O'Neal, DN ; Zozulinska-Ziolkiewicz, D ; Uruska, A ; Jenkins, A (AMER DIABETES ASSOC, 2023-06)
    Introduction: Euglycemic hyperinsulinemic clamps, although costly, time- and labor-intensive, are “gold standard” in measuring insulin sensitivity (IS). Several formulae to estimate IS in people with Type 1 diabetes (T1D) exist (DOI: 10.1007/978-3-030-81303-1_18-1), using various routine and research assays, and with wide ranging IS results. Aim: To develop a free online tool to estimate IS using different metrics and existent formulae and compare estimated IS with measured glucose disposal rate (GDR) from 104 clamp studies. Methods: We prepared an online tool for calculating IS using 17 formulae. Suitable formula(e) are suggested based on available (clinical and research) data. We also compare calculated IS with measured IS (GDR) from clamp studies in 104 adults with T1D (mean±SD) age 34±7 yrs, T1D duration 10±4 yrs, HbA1c 7.7±1.5%, 33 with microvascular complications). Logistic regression was used to infer probability of calculated IS being below GDR=4.45 mg/kg/min or above GDR=6.5 mg/kg/min, which represent respectively the median and 75th percentile of measured GDR values. Results: A calculator is available at www.bit.ly/estimated-GDR and an example result in the Figure 1. Estimated IS varied widely, but results interpretation is generally consistent. Conclusion: We developed an interactive tool to estimate IS in T1D for clinical and research use. Disclosure A.S.Januszewski: None. P.Niedzwiecki: None. N.Sachithanandan: None. G.M.Ward: None. D.N.O'neal: None. D.Zozulinska-ziolkiewicz: Advisory Panel; Abbott, Lilly, Lilly, Novo Nordisk, Medtronic, Speaker's Bureau; Abbott, Ascensia Diabetes Care, Novo Nordisk, Medtronic, Boehringer-Ingelheim, AstraZeneca. A.Uruska: Other Relationship; Lilly, Boehringer-Ingelheim, AstraZeneca, Ascensia Diabetes Care, Sanofi. A.Jenkins: Advisory Panel; Insulet Corporation, Board Member; Insulin for Life, Research Support; Abbott Diabetes, Medtronic, Hemsley Charitable Trust, Juvenile Diabetes Research Foundation (JDRF), National Institutes of Health.
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    Insulinoma: Metastatic Recurrence 38 Years Following Initial Diagnosis in Pregnancy.
    Preston, CA ; Sachithanandan, N ; Sim, I-W ; van Heerden, J ; Farrell, S (The Endocrine Society, 2024-02)
    A case of recurrent insulinoma spanning 4 decades is described. Following a delayed diagnosis, hyperinsulinemic hypoglycemia was confirmed in a 24-year-old woman during early pregnancy. Initial surgery, culminating in subtotal pancreatectomy, was noncurative. A 1-cm insulinoma was subsequently resected from the head of the pancreas postpartum, with postoperative resolution of hypoglycemia. However, 32 years later, the patient experienced a recurrence of hypoglycemic symptoms. Eventually, a subcentimeter extrapancreatic lesion was identified anterior to the pancreatic head on gallium-68 DOTA-Exendin-4 positron emission tomography/computed tomography. In 2022, a third operation was performed, with excision of a 4 × 3 mm tumor adjacent to the pancreatic head, and histology confirming insulinoma. She was again cured of symptoms.