ACR-ACNM-ASTRO-SNMMI Practice Parameter for Lutetium-177 (Lu-177) DOTATATE Therapy.

OBJECTIVES: This practice parameter (PP) for Lutetium-177 (Lu-177) DOTATATE peptide receptor radionuclide therapy (PRRT) aims to guide authorized users in selection of appropriate adult candidates with gastroeneropancreatic neuroendocrine tumors (GEP-NETs) from foregut, midgut, and hindgut. The essential selection criteria include somatostatin receptor-positive GEP-NETs, which are usually inoperable and progressed despite standard therapy. Lu-177 DOTATATE is a radiopharmaceutical with high avidity for somatostatin receptors that are overexpressed by these tumors. This document ensures safe handling of Lu-177 DOTATATE by the authorized users and safe management of affected patients. METHODS: The document was developed according to the systematic process developed by the American College of Radiology (ACR) and described on the ACR Web site (https://www.acr.org/Clinical-Resources/Practice-Parameters-and-Technical-Standards). The PP development was led by 2 ACR Committees on Practice Parameters (Nuclear Medicine and Molecular Imaging and Radiation Oncology) collaboratively with the American College of Nuclear Medicine, American Society of Radiation Oncology, and Society of Nuclear Medicine and Molecular Imaging. RESULTS: The Lu-177 DOTATATE PP reviewed pharmacology, indications, adverse effects, personnel qualifications, and required clinical evaluation before starting the treatment, as well as the recommended posttherapy monitoring, quality assurance, documentation, and appropriate radiation safety instructions provided in written form and explained to the patients. CONCLUSIONS: Lu-177 DOTATATE is available for therapy of inoperable and/or advanced GEP-NETs when conventional therapy had failed. It can reduce tumor size, improve symptoms, and increase the progression free survival. The PP document provides clinical guidance for authorized users to assure an appropriate, consistent, and safe practice of Lu-177 DOTATATE.

ACR-ACNM-ASTRO-SNMMI Practice Parameter for Lutetium-177 (Lu-177) DOTATATE Therapy.

OBJECTIVES: This practice parameter (PP) for Lutetium-177 (Lu-177) DOTATATE peptide receptor radionuclide therapy (PRRT) aims to guide authorized users in selection of appropriate adult candidates with gastroeneropancreatic neuroendocrine tumors (GEP-NETs) from foregut, midgut, and hindgut. The essential selection criteria include somatostatin receptor-positive GEP-NETs, which are usually inoperable and progressed despite standard therapy. Lu-177 DOTATATE is a radiopharmaceutical with high avidity for somatostatin receptors that are overexpressed by these tumors. This document ensures safe handling of Lu-177 DOTATATE by the authorized users and safe management of affected patients. METHODS: The document was developed according to the systematic process developed by the American College of Radiology (ACR) and described on the ACR Web site (https://www.acr.org/Clinical-Resources/Practice-Parameters-and-Technical-Standards). The PP development was led by 2 ACR Committees on Practice Parameters (Nuclear Medicine and Molecular Imaging and Radiation Oncology) collaboratively with the American College of Nuclear Medicine, American Society of Radiation Oncology, and Society of Nuclear Medicine and Molecular Imaging. RESULTS: The Lu-177 DOTATATE PP reviewed pharmacology, indications, adverse effects, personnel qualifications, and required clinical evaluation before starting the treatment, as well as the recommended posttherapy monitoring, quality assurance, documentation, and appropriate radiation safety instructions provided in written form and explained to the patients. CONCLUSIONS: Lu-177 DOTATATE is available for therapy of inoperable and/or advanced GEP-NETs when conventional therapy had failed. It can reduce tumor size, improve symptoms, and increase the progression free survival. The PP document provides clinical guidance for authorized users to assure an appropriate, consistent, and safe practice of Lu-177 DOTATATE.

The Utility of 18FDG PET/CT Versus Bone Scan for Identification of Bone Metastases in a Pediatric Sarcoma Population and a Review of the Literature.

BACKGROUND: Outcome of patients with osteosarcoma (OS) and Ewing sarcoma (EWS) is dependent on presence of metastases. Imaging guidelines for OS and EWS include radiographs, computed tomography (CT), and magnetic resonance imaging for primary tumor evaluation and CT chest and bone scintigraphy (BS) for metastatic detection. 18Fluorodeoxyglucose (18FDG) positron emission tomography (PET)/CT has become more common for disease evaluation, yet there is no consensus for its use in this population. OBJECTIVE: We aimed to compare identification of osseous metastases using BS versus 18FDG PET/CT in our patient population. We hypothesized that 18FDG PET/CT is more likely to detect osseous metastases both at diagnosis and relapse. MATERIALS AND METHODS: We performed retrospective chart reviews of pediatric sarcoma patients treated at our institution from 2008 to 2019. Paired BS and 18FDG PET/CT scans were reviewed. Review of the literature was also performed. RESULTS: Thirty-three patients had paired BS and 18FDG PET/CT during diagnosis or treatment. Fifteen patients had distant osseous metastases. In the OS cohort, 8/16 patients had osseous metastases; 100% of these patients were detected on 18FDG PET/CT and 75% on BS. Thirty-one bony lesions were seen on imaging in OS patients; 100% of these were identified on 18FDG PET/CT but only 29% on BS. In the EWS cohort, 6/15 patients had osseous metastases; 100% of these patients were detected on 18FDG PET/CT and 50% on BS. Eighteen bony lesions were seen on imaging in EWS patients; 94% of these were identified on 18FDG PET/CT, but only 28% on BS. CONCLUSION: For patients in our institution with OS or EWS, osseous metastases were more likely detected using 18FDG PET/CT.

Impact of Patient-Centered Care on the Patient Experience in Nuclear Medicine.

OBJECTIVE: To quantify the impact of direct patient-physician interaction within a nuclear medicine pretherapy consultation clinic on the patient experience. METHODS: Patients were asked to complete a survey before and after meeting with the nuclear medicine physician. During each visit, the physician provided disease-specific information, discussed the planned therapy, answered questions, and provided tip sheets and checklists to prepare the patient for therapy. RESULTS: Thirty-eight patients were included in the analysis. Before consultation, 17 patients (44.7%) were "somewhat" or "extremely" familiar with the term "nuclear medicine doctor," whereas after the consultation, 33 patients (86.8%) were "somewhat" or "extremely" familiar with the term "nuclear medicine doctor" (P < 0.001). Thirteen patients (37.1%) felt they had either no understanding or a vague understanding of the therapy and no understanding of the plan for follow-up before the consultation, whereas 2 patients (5.4%) chose this response after the consultation (P < 0.001). More patients responded that they felt "generally" or "perfectly calm" toward the therapy overall after their consultation: 26 patients (68.4%) before vs 34 patients (91.9%) after consultation (P < 0.001). DISCUSSION: Patient- and family-centered care in radiology includes direct physician participation in care delivery. In this report, we evaluate and measure the impact of our nuclear medicine pretherapy consultation clinic on the patient experience. We demonstrate significant impact of direct patient-physician encounters on patient anxiety, patient knowledge of the role of the nuclear medicine physician, and overall patient understanding of their treatment plan.

18F-Fluorodeoxyglucose PET in Locally Advanced Non-small Cell Lung Cancer: From Predicting Outcomes to Guiding Therapy.

PET using 18-fluorodeoxyglucose (FDG) has become an important part of the work-up for non-small cell lung cancer (NSCLC). This article summarizes advancements in using FDG-PET for patients with locally advanced NSCLC treated with definitive radiation therapy (RT). This article discusses prognostication of outcome based on pretreatment or midtreatment PET metrics, using textural image features to predict treatment outcomes, and using PET to define RT target volumes and inform RT dose modifications. The role of PET is evolving and is moving toward using quantitative image information, with the overarching goal of individualizing therapy to improve outcomes for patients with NSCLC.

Positron Emission Tomography-Adjusted Intensity Modulated Radiation Therapy for Locally Advanced Non-Small Cell Lung Cancer.

PURPOSE: To perform a prospective trial examining positron emission tomography (PET)-based, dose-painted intensity modulated radiation therapy (IMRT) in the setting of locally advanced non-small cell lung cancer (NSCLC). METHODS AND MATERIALS: Patients with stage IIB-III NSCLC were treated with 25 fractions of dose-painted IMRT. Tumors or lymph nodes with metabolic tumor volume exceeding 25 cm3 were deemed "high risk" and received 65 Gy. Smaller lesions were treated with 57 Gy or 52.5 Gy (after November 2014). Patients received concurrent weekly carboplatin (area under the curve = 2) and paclitaxel (45 mg/m2). The primary study endpoint was the absence of high residual metabolic activity (maximum standardized uptake value > 6) in treated lesions on PET 12 to 16 weeks after completion of IMRT. RESULTS: Thirty-five subjects with 116 hypermetabolic lesions were eligible for analysis. The primary endpoint was met for 24 of 30 patients (80%) who underwent posttreatment PET, satisfying our efficacy objective. With a median follow-up duration of 23.8 months for living patients, progression in a lesion targeted with radiation therapy has been observed in 5 patients (14%). Treating progression in other sites and death without progression as competing risks, 2-year cumulative incidence rates of local disease progression in high-risk lesions (n=24) and low-risk lesions (n=92) are 9% and 3%, respectively. The actuarial rate of overall survival at 2 years is 52%. CONCLUSIONS: Dose-painted IMRT based on pretreatment PET metrics with concurrent chemotherapy yields high rates of metabolic response and local disease control for locally advanced NSCLC. Future trials should test this approach to maximize the therapeutic ratio of thoracic radiation therapy.

FDG-PET/CT in the Postoperative Period: Utility, Expected Findings, Complications, and Pitfalls.

FDG-PET/CT as a modality is increasingly used for detection of recurrence and for restaging in patients with clinical suspicion of malignancy, as well as in patients with elevated tumor markers. However, there are many pitfalls in the interpretation of these scans when the studies are performed after some treatment. Some of these are attributed to normal physiological distribution and are compounded when there are inflammatory changes occurring after surgery. The body's inherent response to the surgical insult results in this inflammation. In addition, there are also complications that can happen following surgery, causing increased FDG uptake. Despite various fallacies, FDG-PET/CT provides valuable information in evaluation of residual and recurrent malignant disease. In this article, we aim to describe some of these postsurgical changes secondary to inflammation, common surgical complications, and finally, the utility of FDG-PET/CT in these patients to detect recurrent disease, even in the background of postsurgical changes.

Preoperative 18F-FDG-PET/CT vs Contrast-Enhanced CT to Identify Regional Nodal Metastasis among Patients with Head and Neck Squamous Cell Carcinoma.

Objective Our objective was to compare the accuracy of preoperative positron emission tomography (PET)/computed tomography (CT) and contrast-enhanced CT (CECT) in detecting cervical nodal metastases in patients treated with neck dissection and to scrutinize the ability of each modality to determine nodal stage. Study Design Case series with chart review. Setting Montefiore Medical Center, Bronx, New York. Subjects and Methods Patients who underwent neck dissection at our institution for primary treatment of head and neck squamous cell carcinoma (HNSCC) and had received preoperative PET/CT and CECT were included in this study. Imaging studies were reinterpreted by 3 specialists within the field and compared for interreader agreement. Concordance between radiology and histopathology was measured using neck levels and sides, along with patient nodal stage. Sensitivity, specificity, accuracy, positive predictive value, negative predictive value, and agreement coefficients were calculated. Results Seventy-three patients were included in the study. Sensitivity was 0.69 and 0.94 (level and side) for PET/CT vs 0.53 and 0.66 for CECT ( P = .056, P = .001). Specificity was 0.86 and 0.56 for PET/CT vs 0.91 and 0.76 for CECT ( P = .014, P = .024). No significant difference was found in overall accuracy ( P = .33, P = .88). The overall agreement percentages between N stage called by imaging modality and pathology were 52% and 55% for PET/CT and CECT, respectively. Conclusion No significant difference in sensitivity was found between PET/CT and CECT. CECT was found to have superior specificity compared with PET/CT. The information gleaned from each modality in the pretreatment evaluation of HNSCC appears to be complementary.

Relevance of focal osseous uptake on FDG PET with or without CT changes in oncology patients.

OBJECTIVE: To assess significance of focal FDG uptake in osseous structures, with and without CT correlate, in patients undergoing FDG PET/CT for oncological indications. METHODS: 57 patients with focally increased FDG activity in bones and a definite follow up were included. RESULTS: 85.2% of lesions without changes were found to be malignant. Sensitivity and PPV of a CT correlate in metastatic lesions was expectedly high, 62.9% and 86.7% respectively, however, the NPV was only 14.8%. CONCLUSION: Osseous foci are valuable in predicting metastatic disease even in the absence of low dose CT correlate.

The value of FDG-PET in the staging of gastric adenocarcinoma: A single institution retrospective review.

BACKGROUND: The value of FDG-PET in the staging of gastric adenocarcinoma (GA) has been subject to debate. METHODS: We performed a retrospective review of GA patients between 2006 and 2014 and identified those who had a CT and FDG-PET before initiating treatment. CT and FDG-PET images were analyzed by a blinded body radiologist and nuclear physician, respectively. Disease stage was assessed, looking at primary tumor (PT), locoregional (LLN) and distant lymph node disease (DLN), and metastasis (M). RESULTS: We identified 608 patients who had biopsy-proven GA and 207 (34.0%) had a CT and FDG-PET as part of their staging work-up. Of these, imaging from 166 (27.3%) patients was available for review. CT identified PT, LLN, DLN, and M in 120 (72.3%), 84 (50.6%), 25 (15.1%), and 32 (19.3%) patients, respectively; while FDG-PET identified PT, LLN, DLN, and M in 125 (75.3%), 78 (47.0%), 41 (24.7%), and 27 (16.3%) of patients, respectively. FDG-PET up-staged 31 (18.7%) patients while it down-staged 17 (10.2%) patients. Of patients who were up-staged, 20 (64.5%) developed progressive disease. CONCLUSIONS: Our findings support the use of FDG-PET as a valuable adjunct to CT in the staging of GA, as it changed the stage in 48 (28.9%) patients. J. Surg. Oncol. 2016;113:640-646. © 2016 Wiley Periodicals, Inc.

Evolution of brain imaging instrumentation.

Computed tomography (CT) and static magnetic resonance imaging (MRI) are now the most common imaging modalities used for anatomic evaluation of pathologic processes affecting the brain. By contrast, radionuclide-based methods, including planar imaging, single-photon emission computed tomography (SPECT), and positron emission tomography (PET), are the most widely used methods for evaluating brain function. SPECT and PET have been evolving for a longer time than CT and MRI and have made significant contributions to understanding brain function. The pioneering work on cerebral flow early in the last century laid the foundation of measurement with radioactive gases. This was initially performed with scintillation counters, which gave way to single, then multiple scintillation and multiprobe detectors. The invention of rectilinear scanners, MARK series, Anger cameras, and SPECT imaging further advanced nuclear medicine's role in brain imaging. Measurement of regional cerebral blood flow by SPECT provides pathophysiologic information that directs patient management in a variety of central nervous disorders (CNS), with the greatest clinical impact found in cerebrovascular disease and seizure disorder. In the former, SPECT not only provides means of early detection and localization of acute strokes but can also direct thrombolysis and determine prognosis in the postcerebrovascular accident period. With respect to the latter, ictal SPECT can localize seizure foci so that patients with refractory disease can potentially undergo surgical resection of the affected area. In contrast to brain SPECT, brain PET images reflect regional cerebral metabolism. Because of neurovascular coupling, findings on SPECT and PET images are often comparable. PET, however, still has improved spatial resolution and is therefore more sensitive than SPECT, particularly in the evaluation of dementias. Brain PET instrumentation has greatly evolved from its infancy, when it was used in regional localization, to currently providing excellent resolution with imaging characteristics that can greatly impact clinical management. In addition, although ictal SPECT remains more sensitive than interictal PET for detection of seizure foci, the stringent conditions required for SPECT can be difficult to achieve, making interictal PET a very reasonable alternative. The clinical utility of PET and SPECT in neuropsychiatric and addictive disorders has not yet been defined, though a plethora of data exits. This arena of CNS disease has been the impetus for development of neurotransmitter-receptor-specific radioligands, which have already led to better understanding of dopaminergic, GABAergic, and serotonergic pathways. Another functional brain imaging technique that has gained broad acceptance since its invention in the early 1990 s, is functional MRI, which indirectly measures CNS neuronal activity by evaluating oxygenation levels of cerebral vessels. Despite other recent related developments, such as MR spectroscopy, arterial spin labeling, and diffusion tensor imaging, nuclear medicine-based techniques remain clinically relevant and robust modalities, especially with the ever-expanding armamentarium of radiotracers and radioligands in conjunction with industry-driven improvements in image-analysis hardware and software.

Thyroid cancer--indications and opportunities for positron emission tomography/computed tomography imaging.

Although thyroid cancer is a comparatively rare malignancy, it represents the vast majority of endocrine cancers and its incidence is increasing. Most differentiated thyroid cancers have an excellent prognosis if diagnosed early and treated appropriately. Aggressive histologic subtypes and variants carry a worse prognosis. During the last 2 decades positron emission tomography (PET) and PET/computed tomography (CT), mostly with fluorodeoxyglucose (FDG), has been used increasingly in patients with thyroid cancers. Currently, the most valuable role FDG-PET/CT exists in the work-up of patients with differentiated thyroid cancer status post thyroidectomy who present with increasing thyroglobulin levels and a negative (131)I whole-body scan. FDG-PET/CT is also useful in the initial (post thyroidectomy) staging of high-risk patients with less differentiated (and thus less iodine-avid and clinically more aggressive) subtypes, such as tall cell variant and Hürthle cell carcinoma, but in particular poorly differentiated and anaplastic carcinoma. FDG-PET/CT may help in defining the extent of disease in some patients with medullary thyroid carcinoma and rising postoperative calcitonin levels. However, FDOPA has emerged as an alternate and more promising radiotracer in this setting. In aggressive cancers that are less amenable to treatment with (131)iodine, FDG-PET/CT may help in radiotherapy planning, and in assessing the response to radiotherapy, embolization, or experimental systemic treatments. (124)Iodine PET/CT may serve a role in obtaining lesional dosimetry for better and more rationale planning of treatment with (131)iodine. Thyroid cancer is not a monolithic disease, and different stages and histologic entities require different approaches in imaging and individualized therapy.