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To our knowledge, no prior multicenter clinical trial has reported interobserver agreement of (18)F-FDG PET/CT scans for staging of clinical N0 neck in head and neck cancer. Methods: A total of 287 participants were recruited. For visual analysis, positive nodal uptake of (18)F-FDG was defined as uptake visually greater than activity seen in the blood pool. Results: The negative predictive value of the (18)F-FDG PET/CT for N0 clinical neck was 86% or above for visual assessment (95% CI, 86%–88%) for the 2 central readers and above 90% (95% CI, 90%–95%) for SUV(max) for central reads and site reads dichotomized at the optimal cutoff value of 1.8 and the prespecified cutoff value of 3.5, respectively. The κ coefficients between the 2 expert readers and between central reads and site reads varied between 0.53 and 0.78. Conclusion: The NPV of the (18)F-FDG PET/CT for N0 clinical neck was 86% or above for visual assessment and above 90% for SUV(max) cut points of 1.8 and 3.5 with moderate to substantial agreements.

In the detection and characterization of neuroendocrine tumors (NETs), the NETSPOT 68Ga-DOTATATE positron emission tomography/computed tomography (PET/CT) utilizes a somatostatin analog to capture whole body imaging of somatostatin receptors. Here, we report a rare case of incidental coronavirus disease 2019 (COVID-19) detection using 68Ga-DOTATATE PET/CT for a 48-year-old patient with COVID-19 who presented to our nuclear medicine department for oncologic and neuroendocrine indications. Current maximal intensity project image from 68Ga-DOTATATE PET/CT demonstrated numerous hypermetabolic foci in the upper abdominal lymph nodes, consistent with somatostatin-avid pancreatic islet cell neoplasm. Radiotracer uptake corresponding to the anatomic infiltrates was also seen in the bilateral pneumonia. With the rise of worldwide COVID-19 cases, and the continued use of NETSPOT for somatostatin avid neoplasms, it is imperative that diagnostic measures of this disease are clearly understood. This case highlights the importance of including COVID-19 on the differential diagnosis when radiotracer uptake appears in 68Ga-DOTATATE PET/CT.

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.

PURPOSE The objective of this study was to determine the negative predictive value (NPV) of positron emission tomography (PET)/computed tomography (CT) for the clinically N0 neck on the basis of neck dissection. METHODS Participants with newly diagnosed, first-time, head and neck squamous cell carcinoma (HNSCC) and at least one clinically N0 neck side for which dissection was planned were included. A total of 287 participants were prospectively enrolled from 23 American College of Radiology Imaging Network-qualified institutions. PET/CT was compared with findings at neck dissection. RESULTS PET/CT scans and pathology findings were available for 270 N0 neck sides from 212 participants. For visual assessment, the NPV specific to the clinical-N0 sides was 0.868 (95% CI, 0.803 to 0.925). For dichotomized maximum standardized uptake value, the NPVs specific to the nodal basins were 0.940 (95% CI, 0.928 to 0.952) and 0.937 (95% CI, 0.925 to 0.949) at prespecified cutoffs of 2.5 and 3.5, respectively. The optimal cutoff maximum standardized uptake value was determined to be 1.8, with an NPV of 0.942 (95% CI, 0.930 to 0.953). The PET/CT-informed surgical treatment plan was changed in 51 of 237 participants (22%) compared with the PET/CT-blinded surgical plan. In 34 participants (14%), this led to planned dissection of additional nodal levels. In 12 participants (5%), this led to fewer planned dissected nodal levels. Negative PET/CT scans in N0 necks was true negative in 87% and false negative in 13%. CONCLUSION [18F]fluorodeoxyglucose-PET/CT has high NPV for the N0 neck in T2 to T4 HNSCC. The surgical treatment plans on the basis of PET/CT findings may be changed in approximately 22% of this group. These findings suggest that [18F]fluorodeoxyglucose-PET/CT may assist the clinician in deciding on the best therapy for the clinically N0 neck in HNSCC. Well-designed clinical trials should be performed to test the outcome of omitting neck dissection by using PET/CT.

OBJECTIVE. FDG-PET/CT (fluorodeoxyglucose–positron emission tomography/computed tomography) is effective to assess for occult neck nodal disease. We report risks and patterns of nodal disease based on primary site and nodal level from data on the dissected cN0 per the results from ACRIN 6685. STUDY DESIGN. Prospective nonrandomized enrollment included participants with first-time head and neck squamous cell carcinoma and at least 1 cN0 neck side to be dissected. SETTING. Twenty-four ACRIN-certified centers internationally (American College of Radiology Imaging Network). METHODS. A total of 287 participants were enrolled. Preoperative FDG-PET/CT findings were centrally reviewed and compared with pathology. Incidence, relative risk, pattern of lymph node involvement, and impact upon neck dissection were reported. RESULTS. An overall 983 nodal levels were dissected (n = 261 necks, n = 203 participants). The highest percentages of ipsilateral positive nodes by primary location and nodal level were oral cavity (level I, 17/110, 15.5%), pharynx (level II, 6/30, 20.0%), and larynx (level VI, 1/3, 33.3%). CONCLUSION. Levels at greatest risk for nodal disease in cN0 in terms of ipsilateral neck dissection are level I (oral cavity), II (pharynx), and VI (larynx). These data should be considered when treating patients presenting with cN0. This is the first study to comprehensively report the incidence, location, and risk of metastases in cN0 in the FDG-PET/CT era.

The Society of Nuclear Medicine and Molecular Imaging (SNMMI) is an international scientific and professional organization founded in 1954 to promote the science, technology, and practical application of nuclear medicine. Its 18,000 members are physicians, technologists, and scientists specializing

BACKGROUND Revision parathyroid is challenging due to possible diagnostic uncertainty as well as the technical challenges it can present. METHODS A multidisciplinary panel of distinguished experts from the American Head and Neck Society (AHNS) Endocrine Section, the British Association of Endocrine and Thyroid Surgeons (BAETS), and other invited experts have reviewed this topic with the purpose of making recommendations based on current best evidence. The literature was also reviewed on May 12, 2017. PubMed (1946-2017), Cochrane SR (2005-2017), CT databases (1997-2017), and Web of Science (1945-2017) were searched with the following strategy: revision and reoperative parathyroidectomy to ensure completeness. RESULTS Guideline recommendations were made in 3 domains: preoperative evaluation, surgical management, and alternatives to surgery. Eleven guideline recommendations are proposed. CONCLUSION Reoperative parathyroid surgery is best avoided if possible. Our literature search and subsequent recommendations found that these cases are best managed by experienced surgeons using precision preoperative localization, intraoperative parathyroid hormone (PTH), and the team approach.

We present the case of a 40-year-old male with multiple myeloma for whom bone marrow scintigraphy was utilized to help differentiate between active bony myelomatous disease versus treated lesions with compensatory marrow uptake. This case demonstrates technetium (Tc-99m) sulfur colloid imaging as an inexpensive technique to quickly distinguish between active focal bone disease and reactive marrow.

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.

There are many ways to describe radiation dose to the patient. Clustering the types of radiation into their ability to impart an effect on the human body can be a utilitarian approach. Ionizing radiation versus non-ionizing radiation is a generalization which describes the degree of an effect a type of radiation will have on the human body.

Many surgeons advocate for two concurrent imaging studies for the purpose of localizing a parathyroid adenoma. There is level II evidence for utilizing ultrasound as first-line preoperative imaging and Tc-99 m-sestamibi (MIBI) as a confirmatory technique. When there is concordance of the findings of these two imaging modalities, minimally invasive surgery has a cure rate similar to extensive bilateral neck exploration [1, 2]. This chapter addresses the advanced imaging modalities of magnetic resonance imaging (MRI) and positron emission tomography (PET) which are not considered first-line but may prove useful in select patients. 4D computed tomography (4DCT) is a newer imaging technique which is also considered an advanced imaging modality for parathyroid adenoma localization. This is covered in a separate chapter of this book.

Advances in radiopharmaceuticals and clinical understanding have escalated the use of intraoperative gamma probes in surgery. However, most probes on the market are non-imaging gamma probes that suffer from the lack of ancillary information of the surveyed tissue area. We have developed a novel, hand-held digital Imaging Beta Probe™ (IBP™) to be used in surgery in conjunction with beta-emitting radiopharmaceuticals such as (18)FDG, (131)I and (32)P for real-time imaging of a surveyed area with higher spatial resolution and sensitivity and greater convenience than existing instruments.We describe the design and validation of a hand-held beta probe intended to be used as a visual mapping device to locate and confirm excision of (18)FDG-avid primary tumors and metastases in an animal model.We have demonstrated a device which can generate beta images from (18)FDG avid lesions in an animal model.It is feasible to image beta irradiation in animal models of cancer given (18)FDG. This technology may be applied to clinical mapping of tumors and/or their metastases in the operating room. Visual image depiction of malignancy may aid the surgeon in localization and excision of lesions of interest.

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.

Objectives/Hypothesis: The objective was to determine whether low-frequency repetitive transcranial magnetic stimulation (rTMS) improves tinnitus by decreasing neural activity in auditory processing regions of the temporal cortex and the utility of positron emission tomography (PET) for targeting treatment. Study Design: Randomized, sham-controlled crossover. Methods: Patients received a five-day course of active and sham 1-Hz rTMS (1800 pulses at 110% of motor threshold) to the temporal cortex, with a week separating active and sham treatment. Visual analogue ratings of tinnitus loudness (VARL) were assessed at baseline and the end of each treatment week; regional brain blood flow (rBBF) and glucose metabolism (via PET) were measured before and after treatment in regions of interest (ROI) beneath the stimulating coil and control sites. Results: The VARL for both ears significantly decreased after active but not sham treatment. Responders comprised 43% of patients, experiencing at least a 33% drop in tinnitus loudness. The site most consistently associated with a positive response was the secondary auditory cortex (Brodmann Area 22) in either hemisphere. PET asymmetries were variable across patients and not always accessible to rTMS. Whereas PET activity decreased significantly beneath the stimulating coil following active treatment, similar changes occurred at control sites and after sham stimulation. Change in tinnitus perception did not correlate significantly with change in PET activity at the treatment site ROI. Conclusions: Active TMS led to a significant reduction in tinnitus loudness, but PET scans failed to support the hypothesis that low-frequency rTMS improves tinnitus by reducing cortical activation at the stimulation site, questioning the utility of PET for targeting rTMS. Laryngoscope, 2011

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

The significance of medical imaging in multiple myeloma was established in 1975 with the classic description of the Durie–Salmon staging system which incorporated the presence and number of focal osteolytic lesions in the staging scheme. A third of a century later, this staging system remains in use, though augmented by advances in medical imaging. By the early 1980s, CT imaging demonstrated more focal bone lesions than were seen with standard radiographs as well as extramedullary disease. By the 1980s, MRI imaging revealed skeletal disease that was not apparent by either standard x-rays or CT, focal plasmacytomas in bone that had not yet produced focal osteolysis, and diffuse marrow infiltration. Subsequent work throughout the 1990s developed and established MRI as a very powerful tool to demonstrate the full extent of skeletal disease with resolution approaching a few millimeters. MRI was also used to direct biopsies of focal lesions which increased the detection rate of clinically relevant information compared to random marrow biopsies. However, standard MRI lacked the wide field of view of CT and was both considerably more expensive and less widely available than CT. An additional weakness of standard x-rays, CT, and MRI was their limited utility in the demonstration of response to treatment. By the mid- to late 1990s, the utility of 18F-FDG PET and (after 2000) PET/CT was apparent. PET/CT was particularly powerful since it provided a “whole-body” examination combining the utility of CT (“anatomy”) with a “metabolic” image that was linked to the Warburg physiology of tumors, at a fraction of the cost of an extensive MRI. Thus, PET and PET/CT can demonstrate both active disease and, very importantly, response to treatment. The PET image fused to the CT portion of the PET/CT also provides a “free” whole-body metastatic bone survey that can reveal not only focal bone lesions but also additional clinically relevant findings (fractures or impending fractures, additional malignancies, occult infections, unsuspected regions of tumor involvement such as extramedullary tumor). Recent work has established the fundamental importance of 18F-FDG PET and PET/CT for the baseline evaluation of patients with multiple myeloma and related plasma cell dyscrasias, as well as for subsequent evaluations related to patient management. Future directions for imaging research in multiple myeloma will include PET imaging with isotopes other than 18F-FDG and whole-body MRI.

The current procedure guideline for performing dual-phase (DP) parathyroid scintigraphy, using technetium-99m sestamibi (Tc-99m MIBI) does not mandate the use of single photon emission computed tomography (SPECT) imaging for the detection of parathyroid adenoma (PA) or hyperplasia (PH). The aim of our study was to determine whether DP SPECT (DPS) is significantly superior to DP planar (DPP) imaging in the detection of these abnormalities, justifying its routine use with Tc-99m MIBI parathyroid scintigraphy.Thirty-six consecutive patients with biochemically-proven hyperparathyroidism who subsequently underwent surgical evaluation were studied. All patients underwent early and delayed planar and SPECT imaging at 15 and 90 minutes postinjection of 1.11 GBq (30 mCi) of Tc-99m MIBI. The sensitivity and false-positive rate of DPP and DPS Tc-99m MIBI scintigraphy were compared by retrospectively and blindly interpreting the images and comparing the results with surgical findings.All 36 patients were shown to have either 1 PA (n=27), 2 PAs (n=1), or PH (n=8). Overall, 29 adenomas and 24 hyperplastic glands were found at surgery. On a per patient basis, the sensitivity for the detection of PA or PH for DPP was 42% (15/36) compared with 67% (24/36) for DPS (P = 0.03). For the detection of PAs, the sensitivity of DPP was 54% (15/28) versus 79% (22/28) for DPS (P = 0.05), whereas for the detection of PH, the sensitivities were 0% (0/8) for DPP versus 25% (2/8) for DPS (P = 0.13). There were 2 false-positive scans using DPP versus only 1 false-positive scan with DPS, resulting in false-positive rates of 7% and 4%, respectively. The combination of DPP and DPS did not add any advantage in detecting either PA or PH compared with DPS alone.DPS is significantly more sensitive, and at least as specific, compared with DPP in detecting parathyroid abnormalities in patients with primary hyperparathyroidism and should, therefore, be routinely used when DP Tc-99m MIBI is used in this setting. An algorithm for best utilization of this technique to determine the appropriate surgical approach in patients with primary hyperparathyroidism is presented.

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.

A 69-YEAR-OLD FEMALE with papillary thyroid carcinoma was treated with 1-131 for post-surgical thyroid remnant, which was seen on a pre-therapy 1-123 scan. The post-therapy scans showed two large, rounded foci of 1-131 uptake in the upper abdomen. This is of uncertain significance due to the patient's lack of clinical history to explain the findings. These foci were thought to represent a normal variant of bowel uptake. However, they were found to correlate to large renal cysts bilaterally on a follow-up CT scan. Although renal cyst uptake with 1-131 has been reported in literature, this dramatic illustration with single photon emission computed tomography (SPECT) imaging demonstrates that this physiologic uptake of 1-131 could potentially lead to a false positive interpretation.

A 45-year-old woman with vaginal melanoma underwent Tc-99m sulfur colloid (filtered) lymphoscintigraphy with the acquisition of planar and SPECT/CT images for localization of a sentinel node before surgery. The study identified both inguinal and perirectal sentinel nodes, which proved beneficial in mapping potential anatomic spread of disease for staging and therapy planning. These results provide evidence for the use of routine SPECT/CT imaging for pelvic lymphoscintigraphic studies or as an adjunct tool for localizing sentinel nodes in cases that would not be demonstrated with planar imaging alone.

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.

8532 Background: PET and MRI can reveal intramedullary focal lesions (FL) before osteolysis is detected on metastatic bone survey (MBS). Diagnostic merits, biological/molecular correlates, and outcome implications of the imaging techniques were prospectively and serially evaluated in 269 of 303 newly-diagnosed patients receiving TT3. Methods: Examined were FL number identified by PET (FDG-FL), CT portion of PET (CT-FL), MRI (MRI-FL), and MBS (MBS-FL); additionally, max-SUV of FL (SUV-FL), diffusely-involved bone marrow (SUV-DI), and extramedullary disease (EMD) on PET-CT. Results were compared, laboratory correlates examined (eg: gene expression profiling [GEP]-derived risk, molecular subgroups), and outcome implications determined. Results: Comparing anatomic sites, PET detected the highest mean FL followed by MRI and MBS (p11) (p=0.001) and MRI >23 (p=0.043) in addition to cytogenetic abnormalities (CA) (p=0.005), B2M (>5.5mg/L) (p=0.005), and LDH ((ULN) (p=0.017). Even with GEP-defined high-risk (p=0.008), SUV-FL (>11) (p=0.009) retained independent significance in addition to CA (P8mg/L) (p=0.020). Conclusions: This first prospective comprehensive imaging approach to MM showed that high SUV-FL had significant survival implications even after adjusting for powerful prognostic variables, especially GEP-defined risk. Multifaceted correlations of imaging variables also with molecular features of MM underscore the key role of bone (“soil”) for MM (“seed”) development and progression. [Table: see text]