Hypothalamic and Pituitary Dysfunction After Extensive Brain Surgery: There Is Thirst for More Knowledge.

Craniopharyngiomas are tumors originating from the infundibular stalk, extending to the parasellar and suprasellar region, thereby conferring multiple risks of this region. In particular, hypothalamic and pituitary damage related to its natural history as well as treatment effects of craniopharyngiomas substantially affect life expectancy and quality of life. Here, we describe an adult patient presenting with polyuria, memory, and visual field impairment secondary to concurrent craniopharyngioma and intraventricular glioma. He was treated with surgical resection with postoperative course notable for hypothalamic-pituitary dysfunction, including central hypothyroidism, central adrenal insufficiency, arginine vasopressin deficiency (AVP-D, formerly diabetes insipidus) with loss of sense of thirst, and hypothalamic hypothermia. The adipsia, combined with memory dysfunction, challenged the management of constant fluctuations in his sodium (129-168 mEq/L), with ultimate treatment through vasopressin repletion, fixed fluid intake, strict urine output monitoring, and close counseling of the patient and his caregiver. This case exemplifies the complexity of the endocrine care of patients with craniopharyngiomas and highlights the need for step-wise algorithms in the treatment of hypothalamic deficiencies such as adipsia.

Chemical QuantArray: A Quantitative Tool for Mass Spectrometry Imaging.

Matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI) is a powerful analytical technique that provides spatially preserved detection and quantification of analytes in tissue specimens. However, clinical translation still requires improved throughput, precision, and accuracy. To accomplish this, we created "Chemical QuantArray", a gelatin tissue microarray (TMA) mold filled with serial dilutions of isotopically labeled endogenous metabolite standards. The mold is then cryo-sectioned onto a tissue homogenate to produce calibration curves. To improve precision and accuracy, we automatically remove pixels outside of each TMA well and investigated several intensity normalizations, including the utilization of a second stable isotope internal standard (IS). Chemical QuantArray enables the quantification of several endogenous metabolites over a wide dynamic range and significantly improve over current approaches. The technique reduces the space needed on the MALDI slides for calibration standards by approximately 80%. Furthermore, removal of empty pixels and normalization to an internal standard or matrix peak provided precision (<20% RSD) and accuracy (<20% DEV). Finally, we demonstrate the applicability of Chemical QuantArray by quantifying multiple purine metabolites in 14 clinical tumor specimens using a single MALDI slide. Chemical QuantArray improves the analytical characteristics and practical feasibility of MALDI-MSI metabolite quantification in clinical and translational applications.

Severe Radiation Necrosis Refractory to Surgical Resection in Patients with Melanoma and Brain Metastases Managed with Ipilimumab/Nivolumab and Brain-Directed Stereotactic Radiation Therapy.

BACKGROUND: The use of targeted therapies and immune checkpoint inhibitors has drastically changed the management of patients with melanoma and brain metastases. Specifically, combination therapy with ipilimumab, a cytotoxic T-lymphocyte antigen 4 inhibitor, and nivolumab, a programmed cell death protein 1 inhibitor, has become a preferred systemic therapy option for patients with melanoma and asymptomatic brain metastases. However, the efficacy and toxicity profile of these agents in combination with brain-directed radiation therapy is not well described. CASE DESCRIPTION: In this case series, we highlight a series of patients with melanoma demonstrating severe radiation necrosis immediately refractory to surgical resection following brain-directed stereotactic radiation therapy with concurrent ipilimumab and nivolumab. Three patients described in this series each received stereotactic radiation therapy to a dose of 30 Gy in 5 fractions to a melanoma brain metastasis. These areas developed radiographic evidence of necrosis, which was managed surgically and progressed immediately and rapidly after resection. Re-resection, bevacizumab, steroids, and/or discontinuation of nivolumab was used to mitigate further necrosis with varying efficacy. CONCLUSIONS: Patients with metastatic melanoma receiving brain-directed radiation therapy with concurrent ipilimumab and nivolumab are at risk for developing severe, surgically refractory radiation necrosis and should be closely followed clinically and with imaging. The exact mechanism for such severe necrosis is unknown, and future studies are needed to better understand this pathophysiology and identify optimal treatment strategies.