Cardiac Neuroendocrine Tumor Metastases on 68Ga-DOTATATE PET/CT: Identification and Prognostic Significance.

Neuroendocrine tumor (NET) metastases to the heart are found in 1%-4% of NET patients and have been reported primarily in the form of individual cases. We investigated the prevalence, clinical characteristics, imaging features, and outcomes of NET patients with cardiac metastases on 68Ga-DOTATATE PET/CT. Methods: 68Ga-DOTATATE PET/CT of 490 consecutive patients from a single institution were retrospectively reviewed for sites of metastases. The cumulative cardiovascular event rate and overall survival of patients with cardiac NET metastases (CNMs) were compared with those of a control group of metastatic NET patients without cardiac metastases. In patients with CNMs, the cardiac SUVmax with and without normalization to the myocardial background uptake was compared with a separate cohort of 11 patients with active cardiac sarcoidosis who underwent 68Ga-DOTATATE PET/CT for research purposes. Results: In total, 270 patients with metastatic NETs were identified, 9 (3.3%) of whom had CNMs. All 9 patients had grade 1-2 gastroenteropancreatic NETs, most commonly from the small intestine (7 patients). The control group consisted of 140 patients with metastatic grade 1-2 gastroenteropancreatic NETs. On Kaplan-Meier analysis, there was no significant difference in the risk of cardiovascular adverse events (P = 0.91 on log-rank test) or mortality (P = 0.83) between the metastatic NET patients with and without cardiac metastases. The degree of cardiac DOTATATE uptake was significantly higher in CNMs than in patients with cardiac sarcoidosis without overlap, in terms of both cardiac SUVmax (P = 0.027) and SUVmax-to-myocardial background ratio (P = 0.021). Conclusion: Routine 68Ga-DOTATATE PET/CT can be used to identify CNMs in 3% of patients with metastatic NETs. CNMs do not confer added cardiovascular or mortality risk. A distinguishing feature of CNMs is their high degree of DOTATATE uptake compared with focal myocardial inflammation.

Theranostics in Neuroendocrine Tumors.

ABSTRACT: Neuroendocrine tumors (NETs) are rare tumors that develop from cells of the neuroendocrine system and can originate in multiple organs and tissues such as the bowels, pancreas, adrenal glands, ganglia, thyroid, and lungs. This review will focus on gastroenteropancreatic NETs (more commonly called NETs) characterized by frequent somatostatin receptor (SSTR) overexpression and pheochromocytomas/paragangliomas (PPGLs), which typically overexpress norepinephrine transporter. Advancements in SSTR-targeted imaging and treatment have revolutionized the management of patients with NETs. This comprehensive review delves into the current practice, discussing the use of the various Food and Drug Administration-approved SSTR-agonist positron emission tomography tracers and the predictive imaging biomarkers, and elaborating on 177Lu-DOTATATE peptide receptor radionuclide therapy including the evolving areas of posttherapy imaging practices and peptide receptor radionuclide therapy retreatment. SSTR-targeted imaging and therapy can also be used in patients with PPGL; however, this patient population has demonstrated the best outcomes from norepinephrine transporter-targeted therapy with 131I-metaiodobenzylguanidine. Metaiodobenzylguanidine theranostics for PPGL will be discussed, noting that in 2024 it became commercially unavailable in the United States. Therefore, the use and reported success of SSTR theranostics for PPGL will also be explored.

ACR-ACNM-ARS-ASTRO-SNMMI Practice Parameter for the Performance of Therapy With Radiopharmaceuticals.

OBJECTIVES: This practice parameter was revised collaboratively by the American College of Radiology (ACR), the American College of Nuclear Medicine, the American Radium Society, the American Society for Radiation Oncology, and the Society of Nuclear Medicine and Molecular Imaging. The document is intended to serve as a resource for appropriately trained and licensed physicians who perform therapeutic procedures with unsealed sources, referred to in the document using the more inclusive terminology of radiopharmaceuticals, for which a written directive is required for authorized users under NRC 10 CFR 35.300. METHODS: This practice parameter was developed according to the process described under the heading The Process for Developing ACR Practice Parameters and Technical Standards on the ACR website ( https://www.acr.org/Clinical-Resources/Practice-Parameters-and-Technical-Standards ) by the Committee on Practice Parameters-Radiation Oncology of the ACR Commission on Radiation Oncology in collaboration with the American Radium Society. RESULTS: This practice parameter addresses the overall role of the applicable physician-authorized user, Qualified Medical Physicist, and other specialized personnel involved in the delivery of radiopharmaceutical therapy. Therapeutic radiopharmaceuticals include those administered as elemental radioactive isotopes (radionuclides) or the radioactive element incorporated into a targeting molecule (ligand) by one or more chemical bonds. This document provides guidance regarding general principles of radionuclide therapies and indications of various alpha, beta, gamma, and mixed emission agents with references to several recent practice parameters on new and commonly performed radiopharmaceutical therapies. CONCLUSION: This document addresses clinical circumstances, elements of available agents, and the qualifications and responsibilities of various members of the radiation care team, specifications of consultation and other clinical documentation, post-therapy follow-up, radiation safety precautions, elements of quality control and improvement programs, infection control, and patient education to ensure optimal patient care and safety when utilizing radiopharmaceuticals.

Cancer Informatics for Cancer Centers: Sharing Ideas on How to Build an Artificial Intelligence-Ready Informatics Ecosystem for Radiation Oncology.

In August 2022, the Cancer Informatics for Cancer Centers brought together cancer informatics leaders for its biannual symposium, Precision Medicine Applications in Radiation Oncology, co-chaired by Quynh-Thu Le, MD (Stanford University), and Walter J. Curran, MD (GenesisCare). Over the course of 3 days, presenters discussed a range of topics relevant to radiation oncology and the cancer informatics community more broadly, including biomarker development, decision support algorithms, novel imaging tools, theranostics, and artificial intelligence (AI) for the radiotherapy workflow. Since the symposium, there has been an impressive shift in the promise and potential for integration of AI in clinical care, accelerated in large part by major advances in generative AI. AI is now poised more than ever to revolutionize cancer care. Radiation oncology is a field that uses and generates a large amount of digital data and is therefore likely to be one of the first fields to be transformed by AI. As experts in the collection, management, and analysis of these data, the informatics community will take a leading role in ensuring that radiation oncology is prepared to take full advantage of these technological advances. In this report, we provide highlights from the symposium, which took place in Santa Barbara, California, from August 29 to 31, 2022. We discuss lessons learned from the symposium for data acquisition, management, representation, and sharing, and put these themes into context to prepare radiation oncology for the successful and safe integration of AI and informatics technologies.

Outcomes After Preoperative Chemoradiation With or Without Pazopanib in Non-Rhabdomyosarcoma Soft Tissue Sarcoma: A Report From Children's Oncology Group and NRG Oncology.

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.ARST1321 was a phase II study designed to compare the near complete pathologic response rate after preoperative chemoradiation with/without pazopanib in children and adults with intermediate-/high-risk chemotherapy-sensitive body wall/extremity non-Rhabdomyosarcoma Soft Tissue Sarcoma (ClinicalTrials.gov identifier: NCT02180867). Enrollment was stopped early following a predetermined interim analysis that found the rate of near complete pathologic response to be significantly greater with the addition of pazopanib. As a planned secondary aim of the study, the outcome data for this cohort were analyzed. Eight-five eligible patients were randomly assigned to receive (regimen A) or not receive (regimen B) pazopanib in combination with ifosfamide and doxorubicin + preoperative radiotherapy followed by primary resection at week 13 and then further chemotherapy at week 25. As of December 31, 2021, at a median survivor follow-up of 3.3 years (range, 0.1-5.8 years), the 3-year event-free survival for all patients in the intent-to-treat analysis was 52.5% (95% CI, 34.8 to 70.2) for regimen A and 50.6% (95% CI, 32 to 69.2) for regimen B (P = .8677, log-rank test); the 3-year overall survival was 75.7% (95% CI, 59.7 to 91.7) for regimen A and 65.4% (95% CI, 48.1 to 82.7) for regimen B (P = .1919, log-rank test). Although the rate of near complete pathologic response was significantly greater with the addition of pazopanib, outcomes were not statistically significantly different between the two regimens.

Insurance-Based Disparities in Guideline-Concordant Thyroid Cancer Care in the Era of De-escalation.

INTRODUCTION: Prior studies have demonstrated insurance-based disparities in the treatment of well-differentiated thyroid cancer. However, it remains unclear whether these disparities have persisted in the era of the 2015 American Thyroid Association (ATA) management guidelines. The goal of this study was to assess whether insurance type is associated with the receipt of guideline-concordant and timely thyroid cancer treatment in a modern cohort. METHODS: Patients diagnosed with well-differentiated thyroid cancer between 2016 and 2019 were identified from the National Cancer Database. Appropriateness of surgical and radioactive iodine treatment (RAI) was determined based on the 2015 ATA guidelines. Multivariable logistic regression and Cox proportional hazard regression analyses, stratified at age 65, were used to evaluate the associations between insurance type and appropriateness and timeliness of the treatment. RESULTS: 125,827 patients were included (private = 71%, Medicare = 19%, Medicaid = 10%). Compared to privately insured patients, patients with Medicaid more frequently presented with tumors >4 cm in size (11% versus 8%, P < 0.001) and regional metastases (29% versus 27%, P < 0.001). However, patients with Medicaid were also less likely to undergo appropriate surgical treatment (odds ratio 0.69, P < 0.001), less likely to undergo surgery within 90 d of diagnosis (hazard ratio 0.80, P < 0.001), and more likely to be undertreated with RAI (odds ratio 1.29, P < 0.001). There were no differences in the likelihood of guideline-concordant surgical or medical treatment by insurance type in patients ≥65 y old. CONCLUSIONS: In the era of the 2015 ATA guidelines, patients with Medicaid remain less likely to receive guideline-concordant, timely surgery and more likely to be undertreated with RAI compared to privately insured patients.

Positron Emission Tomography (PET)/Computed Tomography (CT) Imaging in Radiation Therapy Treatment Planning: A Review of PET Imaging Tracers and Methods to Incorporate PET/CT.

Purpose: Positron emission tomography (PET)/computed tomography (CT) has become a critical tool in clinical oncology with an expanding role in guiding radiation treatment planning. As its application and availability grows, it is increasingly important for practicing radiation oncologists to have a comprehensive understanding of how molecular imaging can be incorporated into radiation planning and recognize its potential limitations and pitfalls. The purpose of this article is to review the major approved positron-emitting radiopharmaceuticals clinically being used today along with the methods used for their integration into radiation therapy including methods of image registration, target delineation, and emerging PET-guided protocols such as biologically-guided radiation therapy and PET-adaptive therapy. Methods and Materials: A review approach was utilized using collective information from a broad review of the existing scientific literature sourced from PubMed search with relevant keywords and input from a multidisciplinary team of experts in medical physics, radiation treatment planning, nuclear medicine, and radiation therapy. Results: A number of radiotracers imaging various targets and metabolic pathways of cancer are now commercially available. PET/CT data can be incorporated into radiation treatment planning through cognitive fusion, rigid registration, deformable registration, or PET/CT simulation techniques. PET imaging provides a number of benefits to radiation planning including improved identification and delineation of the radiation targets from normal tissue, potential automation of target delineation, reduction of intra- and inter-observer variability, and identification of tumor subvolumes at high risk for treatment failure which may benefit from dose intensification or adaptive protocols. However, PET/CT imaging has a number of technical and biologic limitations that must be understood when guiding radiation treatment. Conclusion: For PET guided radiation planning to be successful, collaboration between radiation oncologists, nuclear medicine physicians, and medical physics is essential, as well as the development and adherence to strict PET-radiation planning protocols. When performed properly, PET-based radiation planning can reduce treatment volumes, reduce treatment variability, improve patient and target selection, and potentially enhance the therapeutic ratio accessing precision medicine in radiation therapy.