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As COVID-19 vaccination rates continue to rise, it is becoming increasingly important to understand diagnostic imaging associations' resultant from the vaccines. Here, we report a case of a 59-year-old female who was in remission for gastrointestinal neuroendocrine carcinoma and presented for standard follow-up imaging evaluation. Positron-emission tomography (PET) images from a 68Ga-DOTATATE PET (NETSPOT) demonstrated moderate focal radiotracer uptake in the right axilla. Interestingly, this uptake localized to several normal-sized lymph nodes on the corresponding computed tomography (CT). A medical history revealed the patient received both doses of an ipsilateral COVID-19 messenger ribonucleic acid vaccine injection at 17 and 38 days before the PET/CT study. Subsequent scans 2 months later revealed no radiotracer uptake.

OBJECTIVE. The purpose of this study is to provide a concise summary of the current experience with (68)Ga-labeled prostate-specific membrane antigen (PSMA)–11 imaging of prostate and nonprostate malignancies and benign conditions. CONCLUSION. PSMA is overexpressed in prostate cancer and in the neovasculature of many other malignancies. The relevance of PSMA as a biologic target, coupled with advances in the design, synthesis, and evaluation of PSMA-based radionuclides for imaging and therapy, is anticipated to play a major role in patient care.

Prognostic implications of 3 imaging tools, metastatic bone survey, magnetic resonance imaging, and positron emission tomography (PET), were evaluated in 2 consecutive Total Therapy 3 trials for newly diagnosed myeloma. Data including PET at baseline and on day 7 of induction as well as standard prognostic factors were available in 302 patients of whom 277 also had gene expression profiling (GEP)-derived risk information. According to multivariate analysis, more than 3 focal lesions on day 7 imparted inferior overall survival and progression-free survival, overall and in the subset with GEP-risk data. GEP high-risk designation retained independent significance for all 3 end points examined. Thus, the presence of > 3 focal lesions on day 7 PET follow-up may be exploited toward early therapy change, especially for the 15% of patients with GEP-defined high-risk disease with a median overall survival expectation of 2 years. This trial was registered at www.clinicaltrials.gov as #NCT00081939 and # NCT00572169.

Multiple myeloma causes major morbidity resulting from osteolytic lesions that can be detected by metastatic bone surveys. Magnetic resonance imaging and positron emission tomography can detect bone marrow focal lesions long before development of osteolytic lesions. Using data from patients enrolled in Total Therapy 3 for newly diagnosed myeloma (n=303), we analyzed associations of these imaging techniques with baseline standard laboratory variables assessed before initiating treatment. Of 270 patients with complete imaging data, 245 also had gene expression profiling data. Osteolytic lesions detected on metastatic bone surveys correlated with focal lesions detected by magnetic resonance imaging and positron emission tomography, although, in two-way comparisons, focal lesion counts based on both magnetic resonance imaging and positron emission tomography tended to be greater than those based on metastatic bone survey. Higher numbers of focal lesions detected by magnetic resonance imaging and positron emission tomography were positively linked to high serum concentrations of C-reactive protein, gene-expression-profiling-defined high risk, and the proliferation molecular subgroup. Positron emission tomography focal lesion maximum standardized unit values were significantly correlated with gene-expression-profiling-defined high risk and higher numbers of focal lesions detected by positron emission tomography. Interestingly, four genes associated with high-risk disease (related to cell cycle and metabolism) were linked to counts of focal lesions detected by magnetic resonance imaging and positron emission tomography. Collectively, our results demonstrate significant associations of all three imaging techniques with tumor burden and, especially, disease aggressiveness captured by gene-expression-profiling-risk designation. (Clinicaltrials.gov identifier: NCT00081939).

Multiple myeloma (MM) is an incurable plasma cell malignancy of the bone marrow. MM has 3 components: diffuse marrow infiltration, focal bone lesions, and soft-tissue (extramedullary) disease. The hallmark biomarker in blood or urine is a monoclonal immunoglobulin, the monoclonal protein. Waldenstrom macroglobulinemia is a similar disease with secretion of IgM. Staging is classically performed with the 1975 Durie-Salmon system, which includes conventional radiographs. Recently updated, the Durie-Salmon Plus staging system includes CT, MRI, and (18)F-FDG PET/CT. The hallmark radiographic lesion of symptomatic MM is a well-demarcated, focal osteolytic bone lesion. The number of focal bone lesions correlates inversely with outcome. Extramedullary disease is typically an aggressive, poorly differentiated form of MM that confers inferior outcome, with median survival of less than 1 y if present at diagnosis. Achievement of a complete response on (18)F-FDG PET before stem-cell transplantation correlates with a superior outcome.

To determine if standardized uptake values (SUV) on positron emission tomography (PET) are predictive of thyroid pathology and the significance of serial SUV measurements of thyroid nodules over time.Case series with chart review.Academic health center.In total, 23,384 PET and PET/computed tomography (CT) scans were performed between December 2001 and April 2011.Patients with incidental thyroid uptake were identified. SUV(max), age, sex, size of thyroid lesion, indication for PET scan, and cytology/pathology were collected.Incidental thyroid uptake was noted in 1309 PET scans (5.60%), focal uptake in 690 (2.95%), and diffuse uptake in 619 (2.65%). Complete data were available for 359 PET scans from 103 patients. Malignancy was identified in 28 patients (27%). Twenty-five of the 28 lesions (89%) were primary thyroid malignancies. A significant difference between malignant SUV(max) and benign SUV(max) was found (mean ± SD, 7.04 ± 7.88 for malignancies vs 3.85 ± 3.06 for benign tumors, P = .0292). Receiver operating characteristics curves were constructed on patients with PET data within 3 months of diagnosis and indicated that a SUV(max) of 4.2 differentiated maximally between benign and malignant lesions. Serial SUV uptake had no significant change over time.All thyroid nodules with focal uptake on (18)F-fluorodeoxyglucose-PET/CT should be considered at higher risk of malignancy than those discovered incidentally by other imaging modalities. Higher SUV(max) values are more indicative of malignant lesions. All lesions should be evaluated with ultrasonography ± fine-needle aspiration if no clinical contraindications exist. Size of the primary nodule does not influence SUV(max) uptake.

Positron emission tomography (PET) positive lesions are common in the thyroid. The uptake can be focal or diffuse. Diffuse thyroid uptake is thought to be indicative of autoimmune thyroiditis and not for lesions of malignant potential. Hashimoto’s thyroiditis as a cause for diffusely positive thyroid glands has been demonstrated. We determine the incidence of diffuse thyroid PET positivity in hypothyroid patients, presumed to have Hashimoto’s thyroiditis. The study design was retrospective database and electronic medical record review. The study setting includes tertiary care and academic health sciences center. The subjects were patients at our medical center who underwent positron emission tomography. Hypothyroid patients were identified who had total body PET imaging performed for any reason. Patients were excluded if they were not taking levothyroxine, had a history of neck surgery, neck irradiation, Graves’ disease, taking lithium, thalidomide, amiodarone or interleukin. Patients remaining after the application of these exclusion criteria were presumed to be hypothyroid from Hashimoto’s thyroiditis. Only 9.5% of PET scans of hypothyroid patients display diffuse thyroid activity. Only a small minority of presumed Hashimoto’s thyroiditis patients will display diffuse thyroid activity after PET imaging. The etiology of this effect is unknown. Diffuse thyroid activity rarely requires surgical intervention. Level of evidence: IV.

F18-fluorodeoxyglucose positron emission tomography (FDG-PET) is a powerful tool to investigate the role of tumor metabolic activity and its suppression by therapy for cancer survival. As part of Total Therapy 3 for newly diagnosed multiple myeloma, metastatic bone survey, magnetic resonance imaging, and FDG-PET scanning were evaluated in 239 untreated patients. All 3 imaging techniques showed correlations with prognostically relevant baseline parameters: the number of focal lesions (FLs), especially when FDG-avid by PET-computed tomography, was positively linked to high levels of β-2-microglobulin, C-reactive protein, and lactate dehydrogenase; among gene expression profiling parameters, high-risk and proliferation-related parameters were positively and low-bone-disease molecular subtype inversely correlated with FL. The presence of more than 3 FDG-avid FLs, related to fundamental features of myeloma biology and genomics, was the leading independent parameter associated with inferior overall and event-free survival. Complete FDG suppression in FL before first transplantation conferred significantly better outcomes and was only opposed by gene expression profiling-defined high-risk status, which together accounted for approximately 50% of survival variability (R2 test). Our results provide a rationale for testing the hypothesis that myeloma survival can be improved by altering treatment in patients in whom FDG suppression cannot be achieved after induction therapy.

Objectives/Hypothesis: Correlate subjective improvements in tinnitus severity with restoration of cortical symmetry and sustained attention after neuronavigated low-frequency, repetitive transcranial magnetic stimulation (rTMS). Study Design: Case study. Methods: Positron emission tomography and computed tomography imaging (PET-CT) guided rTMS was performed on a 43-year-old white male with more than a 30 year history of bilateral tinnitus. rTMS was administered to the area of increased cortical activation visualized on PET-CT at a rate of 1 Hz for 30 minutes (1,800 pulses/session) for each of 5 consecutive days, with optimization applied on day 5 using single pulses of TMS to temporarily alter tinnitus perception. Subjective tinnitus severity was rated before and after rTMS using the tinnitus severity index with analogue scale. Attention and vigilance were assessed before and after therapy using the psychomotor vigilance task (PVT), a simple reaction time test that is sensitive to thalamocortical contributions to sustained attention. Post-therapy PET-CT was used to evaluate any change in asymmetric cortical activation. Results: The most marked reduction in tinnitus severity occurred after rTMS optimization; this persisted up to 4 weeks after rTMS. PVT testing showed the patient exhibited a statistically significant improvement in mean slowest 10% reaction times after rTMS (P = .004). PET-CT imaging 2 days after the cessation of rTMS showed no changes in cortical blood flow or metabolic asymmetries. Conclusions: Low-frequency rTMS applied to the primary auditory cortex can reduce tinnitus severity, with rTMS optimization yielding the most favorable results. Beneficial changes occurring in the patient's slowest reaction times suggest that attentional deficits associated with tinnitus may also respond to low-frequency rTMS.

Correlate subjective improvements in tinnitus severity with restoration of cortical symmetry and sustained attention after neuronavigated low-frequency, repetitive transcranial magnetic stimulation (rTMS).Case study.Positron emission tomography and computed tomography imaging (PET-CT) guided rTMS was performed on a 43-year-old white male with more than a 30 year history of bilateral tinnitus. rTMS was administered to the area of increased cortical activation visualized on PET-CT at a rate of 1 Hz for 30 minutes (1,800 pulses/session) for each of 5 consecutive days, with optimization applied on day 5 using single pulses of TMS to temporarily alter tinnitus perception. Subjective tinnitus severity was rated before and after rTMS using the tinnitus severity index with analogue scale. Attention and vigilance were assessed before and after therapy using the psychomotor vigilance task (PVT), a simple reaction time test that is sensitive to thalamocortical contributions to sustained attention. Posttherapy PET-CT was used to evaluate any change in asymmetric cortical activation.The most marked reduction in tinnitus severity occurred after rTMS optimization; this persisted up to 4 weeks after rTMS. PVT testing showed the patient exhibited a statistically significant improvement in mean slowest 10% reaction times after rTMS (P = .004). PET-CT imaging 2 days after the cessation of rTMS showed no changes in cortical blood flow or metabolic asymmetries.Low-frequency rTMS applied to the primary auditory cortex can reduce tinnitus severity, with rTMS optimization yielding the most favorable results. Beneficial changes occurring in the patient's slowest reaction times suggest that attentional deficits associated with tinnitus may also respond to low-frequency rTMS.

Radio-guided surgery is an established means for surgeons to identify a target of interest for biopsy or excision. This technique is used for a variety of malignancies as well as minimally invasive parathyroid surgery. The primary radionuclide used for these procedures is technetium-99m (Tc-99m), but others have been used. Use of (18)fluorine-fluorodeoxyglucose ((18)F-FDG) in oncology has proliferated. This has created the opportunity to use (18)F-FDG as a potential radio tracer in the operating room. A pilot study of three patients with non-iodine avid thyroid cancers undergoing (18)F-FDG-guided revision thyroid cancer surgery is reported. Radiation exposure to operating room personnel was measured. Radiation exposure to the surgeon and staff members of an operating room is well below the limits of the National Regulatory Commission. Therefore, utilization of this radiopharmaceutical intraoperatively should not be limited in the future because of concern regarding exposure of operating room personnel to radiation.

Purpose Bisphosphonate-related osteonecrosis of the jaw (BP-ONJ) has become an associated side effect of BP therapy and several imaging modalities have been studied to show an ability to detect clinical disease. Because most patients at the authors' university hospital who develop BP-ONJ also undergo concurrent positron emission tomographic (PET) scanning, the authors investigated the utility of PET scans for diagnosis of BP-ONJ. Patients and Methods A retrospective chart review was performed of patients whose PET scans were acquired within 1 year of their BP-ONJ diagnosis (1998 through 2006). BP-ONJ was defined as intraoral exposure of the maxilla or mandible in patients on BPs and not given radiation to that area. This was performed at a university hospital with oncologic patients treated with BPs. All PET scans in this study were secondarily reviewed by a single expert reader for internal consistency (T.B.B.). A detailed timeline of the course of BP-ONJ was constructed by the review of medical records for each patient and the relation of each patient's PET scan results to that patient's BP-ONJ disease was evaluated. Data analysis was a descriptive analysis of PET scan findings in this patient population. Results Of the 25 patients studied, 5 were excluded for insufficient clinical or radiologic data. Of the 20 remaining patients (16 male, 4 female), 46 PET scans were performed and showed 53 areas of enhancement. Many patients had multiple PET scans performed while experiencing exposed bone, and 5 of these patients had alternating positive and negative scans with exposed bone, resulting in 13 patients with positive enhancement on a scan with exposed bone and 9 patients with no enhancement on a scan with exposed bone. Of the 13 patients with PET enhancement, 4 had signs of clinical infection documented at the time of examination. Sensitivity, specificity, and accuracy of PET scanning for BP-ONJ were 43%, 19%, and 62%, respectively. There were 7 patients with PET scans performed after clinical resolution of their exposed bone and 6 of those had no enhancement. Conclusion The purpose of this study was to report findings on PET scanning for patients with BP-ONJ. Although PET scans are useful in oncology, the present findings do not support their routine use for exclusively diagnosing or following cases of BP-ONJ.

Background We present our experience with the use of an immunocompetent medium-sized animal model of tongue cancer that may be suitable for imaging and surgical studies. Methods A New Zealand white rabbit model of tongue cancer was created by injecting a VX tumor cell suspension grown in culture into the tongue of our model. The tumor was examined 7 days following implantation by physical examination, photography, and 18fluoro 2-deoxyglucose–positron emission tomography (FDG-PET). At 12 days postimplantation, the model was again studied as described above prior to euthanization, and then tongue excision and bilateral neck dissections were performed. All tissue was examined by histology. Results We confirmed a successful orthotopic tongue cancer model that resulted in cervical nodal metastases. Conclusion This model may be a useful model of orthotopic head and neck cancer for future surgical or imaging research. © 2012 Wiley Periodicals, Inc. Head Neck, 2013

Objectives/Hypothesis: A single patient was tested to examine the safety and feasibility of using maintenance sessions of low-frequency repetitive transcranial magnetic stimulation (1 Hz rTMS) to reduce tinnitus loudness and prevent its return over time. Study Design: Interrupted time series with multiple replications. Methods: Tinnitus loudness was assessed using a visual analogue rating (VAR) with 0 = no tinnitus, and 100 = loudest tinnitus experienced; 1,800 TMS pulses delivered at 1 Hz and 110% of motor threshold were administered over the posterior, superior lateral temporal gyrus of the subject's right hemisphere until subjective tinnitus fell to a VAR of 25. TMS was reapplied as tinnitus returned to a VAR of 25 or higher. Cerebral metabolism was measured using positron emission tomography before and after treatment. Results: In this patient, tinnitus could be reduced to a VAR of 6 or lower each time it reoccurred using one to three maintenance sessions of rTMS. Tinnitus loudness remained at or below a VAR of 25 and was reported to be unobtrusive in daily life when last assessed 4 months after the third and final round of maintenance treatment. Asymmetric increased cerebral metabolism in the right hemisphere reduced following treatment and as tinnitus improved. Maintenance treatment was well tolerated with no side effects. Conclusions: Although a case study cannot establish treatment efficacy, this study demonstrates for the first time that it is feasible to use maintenance rTMS to manage chronic tinnitus. Maintenance rTMS might impede cortical expansion of the tinnitus frequency into adjacent cortical areas, but group studies are necessary to confirm this speculation.

Diagnosing bone infection in its acute early stage is of utmost clinical importance as the failure to do so results in a therapeutically recalcitrant chronic infection that can only be resolved with extensive surgical intervention, the end result often being a structurally unstable defect requiring reconstructive procedures. [(18)F]-FDG-PET has been extensively investigated for this purpose, but the results have been mixed in that, while highly sensitive, its specificity with respect to distinguishing between acute infection and sterile inflammatory processes, including normal recuperative post-surgical healing, is limited. This study investigated the possibility that alternative means of acquiring and analyzing FDG-PET data could be used to overcome this lack of specificity without an unacceptable loss of sensitivity. This was done in the context of an experimental rabbit model of post-surgical osteomyelitis with the objective of distinguishing between acute infection and sterile post-surgical inflammation. Imaging was done 7 and 14 days after surgery with continuous data acquisition for a 90-minute period after administration of tracer. Results were evaluated based on both single and dual time point data analysis. The results suggest that the diagnostic utility of FDG-PET is likely limited to well-defined clinical circumstances. We conclude that, in the complicated clinical context of acute post-surgical or post-traumatic infection, the diagnostic utility accuracy of FDG-PET is severely limited based on its focus on the increased glucose utilization that is generally characteristic of inflammatory processes.