The United States Department of Energy and National Institutes of Health Collaboration: Medical Care Advances via Discovery in Physical Sciences

Over several months, representatives from the U.S. Department of Energy (DOE) Office of Science and National Institutes of Health (NIH) had a number of meetings that lead to the conclusion that innovations in the Nation's health care could be realized by more directed interactions between NIH and DOE. It became clear that the expertise amassed and instrumentation advances developed at the DOE physical science laboratories to enable cutting-edge research in particle physics could also feed innovation in medical healthcare. To meet their scientific mission, the DOE laboratories created advances in such technologies as particle beam generation, radioisotope production, high-energy particle detection and imaging, superconducting particle accelerators, superconducting magnets, cryogenics, high-speed electronics, artificial intelligence, and big data. To move forward, NIH and DOE initiated the process of convening a joint workshop which occurred on July 12th and 13th, 2021. This Special Report presents a summary of the findings of the collaborative workshop and introduces the goals of the next one.

PSAT387 An Unusual Case of Sporadic Metastatic Medullary Thyroid Cancer Without a Primary Tumor Presenting with Paraneoplastic Cushing's Syndrome

Introduction

Medullary thyroid carcinoma (MTC) accounts for 5-10% of all thyroid cancers and up to 30% of MTCs are hereditary. Only 0.6% of MTCs are associated with a paraneoplastic ACTH-dependent Cushing's syndrome (CS) (PMID: 16029131). Even rarer are MTCs without a primary intra-thyroidal tumor. Here we describe a patient with metastatic MTC without a known primary intrathyroidal tumor presenting with paraneoplastic ACTH-dependent CS.

Clinical Case

A 47-year-old Ukrainian man was referred to our center for management of metastatic MTC. During evaluation of refractory diarrhea two years earlier, an elevated serum calcitonin (1758 pg/mL, normal: <11.5) led to the diagnosis. Thyroid ultrasound revealed a normal thyroid with bulky cervical lymphadenopathy. Cervical lymph node biopsy revealed metastatic MTC with positive calcitonin, synaptophysin, and chromogranin-A on immunohistochemistry (IHC) and RET protooncogene M918T pathogenic variant on molecular testing. Germline testing for RET pathogenic variants was negative. Prior to referral, the patient was on octreotide to control diarrhea and vandetanib for a few months, but they were discontinued due to financial stress. At our center, patient complained of 4-6 watery bowel movements daily. Physical examination revealed facial plethora, dorsocervical fat pad, central adiposity, wide purple striae, and pustular acne on the chest wall and proximal muscle weakness.

Biochemical testing revealed elevated serum calcitonin (158,535 pg/mL, normal: <14.3), carcinoembryonic antigen (3,634 ng/mL, normal: 0.8–6.2), and chromogranin-A (5504 ng/mL, normal<93) levels. Morning serum cortisol (40.4 mcg/dL, normal: 3.7–19.4), and plasma ACTH (116.0 pg/mL, normal: 5.0-46.0) levels were elevated, along with markedly elevated 24-hour urine free cortisol levels (12,460.8 mcg/24-hour, normal: 35-45.0), consistent with ACTH-dependent Cushing's syndrome. Further IHC testing of the tumor biopsy sample revealed mild ACTH positivity. A pituitary MRI was normal. Stool osmolality studies showed a secretory diarrhea pattern. Computed tomography (CT) of neck and torso demonstrated bulky cervical, retroperitoneal, and inguinal lymphadenopathy, and extensive liver metastasis, all of which were strongly avid on an 18-fluorodeoxyglucose positron emission tomography CT scan, but poorly avid on a gallium-68 DOTATATE scan. Sodium fluoride bone scan revealed multiple osseous metastases in the spine, ribs, pelvis, and in the right femoral shaft. An adrenal CT scan revealed bilateral adrenal hyperplasia.

The patient was unfortunately not eligible for any ongoing local clinical trials on RET-mutated cancer therapies. After extensive discussion with the patient, a palliative approach was pursued. The cervical lymphadenopathy and right femoral shaft metastasis were treated with external beam radiation. Diarrhea was controlled with loperamide. Cushing's syndrome was initially managed with metyrapone and ketoconazole, followed by bilateral adrenalectomy and hydrocortisone and fludrocortisone replacement.

Conclusion

Sporadic metastatic MTC can rarely present without an intrathyroidal primary tumor and may originate from ectopic C-cells. Paraneoplastic syndromes such as Cushing's syndrome can be observed in MTC due to ectopic-ACTH production.

Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m.

Translating a radiolabeled imaging agent to the clinic

Molecular Imaging is entering the most fruitful, exciting period in its history with many new agents under development, and several reaching the clinic in recent years. While it is unusual for just one laboratory to take an agent from initial discovery through to full clinical approval the steps along the way are important to understand for all interested participants even if one is not involved in the entire process. Here, we provide an overview of these processes beginning at discovery and preclinical validation of a new molecular imaging agent and using as an exemplar a low molecular weight disease-specific targeted positron emission tomography (PET) agent. Compared to standard drug development requirements, molecular imaging agents may benefit from a regulatory standpoint from their low mass administered doses, they nonetheless still need to go through a series of well-defined steps before they can be considered for Phase 1 human testing. After outlining the discovery and preclinical validation approaches, we will also discuss the nuances of Phase 1, Phase 2 and Phase 3 studies that may culminate in an FDA general use approval. Finally, some post-approval aspects of novel molecular imaging agents are considered.

Tumor Response to Radiopharmaceutical Therapies: The Knowns and the Unknowns

Radiopharmaceutical therapy (RPT) is defined as the delivery of radioactive atoms to tumor-associated targets. In RPT, imaging is built into the mode of treatment since the radionuclides used in RPT often emit photons or can be imaged using a surrogate. Such imaging may be used to estimate tumor-absorbed dose. We examine and try to elucidate those factors that impact the absorbed dose-versus-response relationship for RPT agents. These include the role of inflammation- or immune-mediated effects, the significance of theranostic imaging, radiobiology, differences in dosimetry methods, pharmacokinetic differences across patients, and the impact of tumor hypoxia on response to RPT.

Bowel and bladder reproducibility in image-guided SBRT prostate: Results of a patterns of practice survey

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Background: Use of prostate stereotactic body radiotherapy (SBRT) as treatment for localized prostate cancer (PCa) is increasing. Given the high dose (>5Gy) per fraction (Fx) being delivered, SBRT requires careful preparation and delivery to ensure accuracy and precision. Guidelines and data on best practice for bowel and bladder preparation are lacking. Therefore, we surveyed practicing radiation oncologists (RO) to document practice patterns for prostate SBRT. Methods: From June to October 2018 we completed a nationwide survey of 1395 American Society for Therapeutic Radiology and Oncology (ASTRO) members who self-identified as managing PCa. A SurveyMonkey link was sent via email, and analysis included practicing RO who treat PCa with SBRT. Results: 204 responses were received with 32% (64/204) using SBRT. 80% (51/64) provided the fractionation used: 33% (17/51) use 35Gy to 36.25Gy, and 17.6% (9/51) use >40Gy in 5 Fx, and 1 used >9Gy Fx. 94% use implantable devices for localization (83% fiducial markers, 17% radiofrequency transponders). 65% (42/64) use a hydrogel spacer. 75% (48/64) use daily cone beam CT (CBCT) for image guidance. The majority use a 5 mm PTV, with 3 mm posteriorly. For bladder and bowel preparation 97% (62/64) provided preferences. For bladder, 90.3% (56/62) required a comfortably full bladder for both simulation and treatment. For simulation, 92% (57/62) have a bowel protocol (BP) to optimize rectal reproducibility. 51.6% (31/62) have patients empty their bowels prior, and 51.6% (31/62) prescribe a BP. Diet alteration was recommended by 77% (48/62). 86% (53/62) used a BP during SBRT treatment. Of those using a BP, 67% (43/64) continued it throughout SBRT with 30% (19/64) continuing BP unless symptoms change management. Only 3% (2/64) stop BP after simulation. Conclusions: The variability of data in the literature on effective BP for treatment reproducibility for PCa is reflected in the varied patterns of practice seen in our survey. Consensus on bladder preparation is seen for a majority of practitioners. A variety of BP regimens are employed.