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PURPOSE To quantify the relationship of the tumor-to-normal ratio (TNR) attained from the technetium-99m macroaggregated albumin (MAA) and posttreatment yttrium-90 bremsstrahlung (Y90-Brem) single-photon emission computerized tomography (SPECT)/computer tomography (CT) studies in patients with hepatocellular carcinoma (HCC) treated with glass microspheres. MATERIALS AND METHODS Retrospectively, a total of 190 consecutive patients with HCC who underwent 204 MAA and Y90-Brem SPECT/CT for glass microsphere Y90 radiation segmentectomy (Y90-RS) or lobar treatment (Y90-RLT) between 2013 and 2018 were included. Semi-automated regions-of-interests were drawn around the targeted tumor and nontumoral liver tissue on the SPECT/CT studies. TNR values from MAA and Y90-Brem SPECT/CT were compared using paired t-tests, Pearson correlation, and median with interquartile ranges (IQR). RESULTS The mean TNR for MAA and Y90-Brem SPECT/CT was 2.96 ± 1.86 (median, 2.64; IQR, 2.50) and 2.29 ± 1.10 (median, 2.06; IQR, 1.05), respectively (P < .0001). The mean Y90-RLT TNR was 2.88 ± 1.67 (median, 2.59; IQR, 0.83) and 2.17 ± 0.89 (median, 1.98; IQR, 0.81) for MAA and Y90-Brem SPECT/CT, respectively (P < .0001). The mean Y90-RS TNR was 3.02 ± 2.01 (median, 2.87; IQR, 3.01) and 2.39 ± 1.25 (median, 2.11; IQR, 1.28) for MAA and Y90-Brem SPECT/CT, respectively (P = .0003). TNR attained from MAA and Y90 SPECT/CT studies showed a moderate correlation in a positive linear fashion for the overall (r = 0.54; P < .001), Y90-RLT (r = 0.66, P < .001), and Y90-RS cohorts (r = 0.48, P < .001). CONCLUSIONS The TNR attained from Y90-Brem SPECT/CT is often underestimated, positively correlated, and less variable than that attained from MAA SPECT/CT.

Purpose The aim of the study was to evaluate the effects of tumour dose on tumour response and overall survival (OS) in patients with chemo-refractory metastatic breast cancer (MBC) to the liver undergoing yttrium-90 radioembolisation (Y90 RE). Materials and methods In 20 consecutive patients with chemo-refractory MBC to the liver undergoing 33 total Y90 RE resin treatments, volumes of interest were drawn around the five largest tumours of the targeted liver lobe on post-Y90 RE Bremsstrahlung single-photon emission computed tomography/computed tomography using MIM software v.6.9 (MIM Software, Cleveland, Ohio, USA) and dose-volume histograms were calculated. Response Evaluation Criteria in Solid Tumours (RECIST) was used to determine tumour response at 3 months. Receiver operating characteristics (ROC) curves were used to determine thresholds for various dosimetry parameters. Kaplan-Meier estimation was used to determine OS. Results Overall, 11 of 33 (33%) Y90 RE treatments resulted in complete or partial response according to RECIST criteria with a median OS of 20.97 months compared to 11.73 months for nonresponders (P = 0.003). Mean tumour dose, defined as the aggregate tumour dose of up to the five largest tumours in the targeted lobe, was the most predictive of tumour response with the highest area under the ROC curve of 0.967. Mean tumour dose >70 Gy had 91% sensitivity and 100% specificity for predicting tumour response. Patients with mean tumour dose >70 Gy experienced a median OS of 16.1 months vs. 12.8 months for those who did not (P = 0.008). Conclusion For patients with chemo-refractory breast cancer with liver metastases, achieving a mean tumour dose >70 Gy is a significant predictor of tumour response and prolonged OS.

Gastroparesis is a debilitating disease of insufficient gastric emptying and visceral hypersensitivity characterized by nausea, vomiting, early satiety, and bloating. Gastric emptying scintigraphy (GES), in combination with typical symptoms and normal esophagogastroduodenoscopy findings, is used to diagnose the disease. Gastric per-oral endoscopic pyloromyotomy (G-POEM) has emerged as a novel technique for treating gastroparesis, with up to an 80% success rate. This procedure involves myotomy of the distal stomach. We hypothesize that responders to this therapy are characterized by more distal dysmotility than nonresponders, as defined by GES retention patterns. Methods: We used regional gastric emptying measurements from diagnostic GES to determine the proximal or distal predominance of disease for each patient. We then compared treatment response and symptoms in each patient to total gastric half-emptying time (T½), proximal gastric T½, and a ratio comparing the 2 values. Results: In total, 47 patients underwent G-POEM during the study period. A significant difference (P < 0.01) was found in proximal-to-total T½ ratio between responders and nonresponders. A significant difference between pre- and postprocedural proximal-to-total T½ ratios was identified for each patient. No correlations were identified between motility patterns and symptoms or in motility patterns among the different etiologies of the disease. Conclusion: Proximal-to-total T½ ratio may represent an important patient selection factor for G-POEM versus other treatment modalities going forward. Local retention patterns in GES may not inform the symptom profile in gastroparesis.

Gastric emptying scintigraphy (GES) helps to diagnose gastroparesis and is typically only used for whole stomach retention patterns. However, it may provide significantly more information when looking specifically at proximal and distal retention patterns. This article reviews global GES changes following gastric per oral endoscopic myotomy; how global, proximal, and distal GES measurements correlate to gastroparesis symptoms; and how proximal and distal GES may serve as proxies for the various mechanisms involved in gastroparesis. The authors' data on how GES may be used to select which patients will have success from G-POEM is also reviewed.

The purpose of this chapter is to introduce the reader to the fundamentals of image processing in Nuclear Medicine. It is not meant as a comprehensive guide, but more as an overview and introduction to those topics important to understanding the various forms of image processing.

BACKGROUND The coronavirus disease 2019 (COVID-19) pandemic has made it more challenging for patients to undergo yttrium-90 (Y-90) radioembolization (RE). Same day Y-90 RE provides an opportunity to minimize logistical challenges and infection risk associated with COVID-19, thus improving patient access. AIM To describe the use of same day Y-90 RE with routine single photon emission computed tomography/computed tomography (SPECT/CT) in order to optimize therapy. METHODS All patients were selected for Y-90 RE through a multidisciplinary tumor board, and were screened and tested for COVID-19 infection per institutional protocol. A same day procedure was developed, consisting of angiography, imaging, and Y-90 resin particle delivery. Routine SPECT/CT after technetium-99m macroaggregated albumin (Tc-99m MAA) administration was performed for assessment of arterial supply, personalized dosimetry, and extrahepatic activity. Post-treatment Y-90 bremsstrahlung SPECT/CT was performed for confirmation of particle delivery, by utilization of energy windowing to limit signal from previously administered Tc-99m MAA particles. RESULTS A total of 14 patients underwent same day Y-90 RE between March and June 2020. Mean lung shunt fraction was 6.13% (range 3.5%-13.1%). Y-90 RE was performed for a single lesion in 7 patients, while the remaining 7 patients had treatment of multifocal lesions. The largest lesion measured 8.3 cm. All patients tolerated the procedure well and were discharged the same day. CONCLUSION Same day Y-90 RE with resin-based microspheres is feasible, and provides an opportunity to mitigate infection risk and logistical challenges associated with the COVID-19 pandemic and beyond. We recommend consideration of SPECT/CT, especially among patients with complex malignancies, for the potential to improve outcomes and eligibility of patients to undergo same day Y-90 RE.

To compare the efficacies of glass and resin-based Yttrium-90 microspheres by comparing absorbed tumor dose (TD) with both tumor response (TR) and overall survival (OS) in patients with chemorefractory intrahepatic cholangiocarcinoma (ICC). Post-Y90 treatment bremsstrahlung SPECT/CT of 38 consecutive patients receiving 45 treatments (21 resin microspheres, 24 glass microspheres) were analyzed retrospectively. MIM software v6.9.4 (MIM Software Inc, Cleveland, OH) was used to calculate targeted tumors’ dose volume histogram. Modified Response Evaluation Criteria in Solid Tumors was used to evaluate tumor response 3 months post-treatment. Kaplan Meier estimation was used for survival analysis. T-test was used to compare the devices on various dosimetric parameters. Thresholds for TD to predict TR with ≥ 80% specificity were as follows: mean TD (Resin: 78.9 Gy; Glass: 254.7 Gy), maximum TD (Resin: 162.9 Gy; Glass: 591 Gy), minimum TD (Resin: 53.7 Gy; Glass: 149.1 Gy). Microsphere type had no effect on survival from first Y90 (Resin: 11.2 mo; Glass 10.9 mo [p = 0.548]). In patients receiving resin microspheres, mean TD ≥ 75 Gy or maximum TD ≥ 150 Gy was associated with median OS of 20.2 mo compared to 6.5 mo for those receiving less (p = 0.001, 0.002, respectively). For patients treated with glass microspheres, those receiving a mean TD ≥ 150 Gy had a median OS of 14.6 mo vs. 2.6 mo for those receiving less (p = 0.031). TD thresholds predictive of TR and OS differ significantly between glass and resin microspheres. However, microsphere type has no impact on survival in patients with chemorefractory ICC. Level 3, Retrospective Study.

To compare lung shunt fraction (LSF) prior to Y-90 radioembolization calculated using planar imaging versus SPECT/CT in patients with hepatocellular carcinoma (HCC). A single institution retrospective analysis of technetium-99m macroaggregated albumin (Tc-99m MAA) LSF studies for 293 consecutive patients with HCC between 2013 and 2018 was performed. LSF using planar imaging (PLSF) was compared to retrospectively calculated LSF using SPECT/CT (SLSF) via semiautomated segmentation using MIM v.6.9. Sub-analyses of patients were performed based on PLSF range, tumor size, BCLC stage, and Child–Pugh (C–P) score. Mean LSF absolute discrepancy between sub-groups was analyzed. Comparisons were performed using paired t tests and linear regression analysis. Mean PLSF, 8.27%, was greater than mean SLSF, 3.27% (p

The purpose of this document is to assist nuclear medicine practitioners in recommending, performing, interpreting, and reporting the results of gated equilibrium radionuclide angiocardiography (ERNA).

The complication profile following repeat Y-radioembolization (RE) is not well understood, and repeat RE is sometimes avoided because of concerns for RE-induced liver disease (REILD) and liver toxicity. The purpose of this study was to examine the incidence of REILD and liver toxicity following repeat Y-RE and to identify potential risk factors.A retrospective analysis of patients undergoing repeat RE to the same hepatic lobe between 2013 and 2018 was performed. Baseline factors were evaluated as predictors of liver toxicity, mortality, and REILD, which was defined as the presence symptomatic ascites or jaundice in the absence of biliary obstruction within 8 weeks following RE. Post-RE complications were graded according to the Common Terminology Criteria for Adverse Events version 5.A total of 39 patients underwent repeat RE with 14 (35.9%) experiencing Common Terminology Criteria for Adverse Events toxicity of grade 2 or greater, 3 (10.3%) grade 3, and no grade 4 or greater. A Model for End Stage Liver Disease score of 8 or greater was associated with grade 2 toxicity or greater (26.7% vs 75%; P = 0.013). Only 3 patients (7.7%) experienced REILD due to symptomatic ascites without jaundice. Greater than 2 REs were associated with a greater rate of 6-month mortality (12% vs 58.3%, P = 0.003), 12-month mortality (28% vs 75%, P = 0.007), and REILD (0% vs 21.4%, P = 0.016). Age, sex, microsphere type, cirrhosis, Child-Pugh, and Eastern Cooperative Oncology Group status were not significantly associated with complications, REILD, or survival.Repeat Y-RE appears to be well tolerated with a low rate of high-grade adverse events and REILD.

This information statement from the American Society of Nuclear Cardiology highlights advances in cardiac SPECT imaging and supports the incorporation of new technology and techniques in laboratories performing nuclear cardiology procedures. The document focuses on the application of the latest imaging protocols and the utilization of newer hardware and software options to perform high quality, state-of-the-art SPECT nuclear cardiology procedures. Recommendations for best practices of cardiac SPECT imaging are discussed, highlighting what imaging laboratories should be doing as the standard of care in 2018 to achieve optimal results (based on the ASNC 2018 SPECT guideline [Dorbala et al., J Nucl Cardiol. 2018. https://doi.org/10.1007/s12350-018-1283-y ]).

Background Assessment of thyroid cartilage invasion (tumor extension through inner cortex) and thyroid cartilage penetration (tumor involving both the inner and outer cortices of thyroid cartilage) may be challenging with CT (Computed Tomography) and MR imaging (Magnetic Resonance Imaging). Positron Emission Tomography/Computed Tomography (PET/CT) is a non invasive imaging modality that provides both anatomic and metabolic information. Quantitative data obtained from PET/CT, also known as PET/CT parameters, include maximum, mean or peak standardized uptake values (SUVmax, SUVmean, SUVpeak), metabolic tumor volume (MTV), total lesion glycolysis (TLG), standardized added metabolic activity (SAM) and normalized standardized added metabolic activity (NSAM). Our aim was to examine if FDG PET/CT parameters could differentiate thyroid cartilage invasion from penetration. Methods 50 patients who underwent PET/CT before laryngectomy for squamous cell carcinoma of the larynx, had SUVmax, SUVmean, SUVpeak, TLG, MTV, SAM and NSAM calculated on a dedicated workstation. Univariate and multivariate analysis was performed. ROC analysis was used to determine the ability of PET/CT parameters to predict pathologically proven thyroid cartilage invasion or penetration. Results Of the 50 patients, 50% (25/50 patients) had history of prior radiation therapy. Among the previously irradiated group, 24% had thyroid cartilage invasion and penetration. 8% of the patients in this group had thyroid cartilage invasion only. Among the non-irradiated group, 76% had thyroid cartilage invasion and penetration, 8% had thyroid cartilage invasion without penetration. ROC analysis revealed that none of the PET/CT parameters had enough power to predict thyroid cartilage penetration, but TLG, MTV and SAM had enough power to predict thyroid cartilage invasion in non-irradiated patients. TLG, MTV, SAM and NSAM had enough power to predict thyroid cartilage invasion and penetration in irradiated group. Conclusion TLG, MTV and SAM have enough power to predict thyroid cartilage invasion and penetration in irradiated patients. PET/CT parameters do not have enough potential to differentiate thyroid cartilage invasion from penetration.

This study was designed to seek associations between positron emission tomography/computed tomography (PET/CT) parameters, contrast enhanced neck computed tomography (CECT) and pathological findings, and to determine the potential prognostic value of PET/CT and CECT parameters in oral cavity squamous cell carcinoma (OCSCC).36 OCSCC patients underwent staging PET/CT and 30/36 of patients had CECT. PET/CT parameters were measured for the primary tumor and the hottest involved node, including maximum, mean, and peak standardized uptake values (SUV max, SUV mean, and SUV peak), metabolic tumor volume (MTV), total lesion glycolysis (TLG), standardized added metabolic activity (SAM), and normalized standardized added metabolic activity (N SAM). Qualitative assessment of PET/CT and CECT were also performed. Pathological outcomes included: perineural invasion, lymphovascular invasion, nodal extracapsular spread, grade, pathologic T and N stages. Multivariable logistic regression models were fit for each parameter and outcome adjusting for potentially confounding variables. Multivariable Cox proportional hazards models were used for progression free survival (PFS), locoregional recurrence free survival (LRFS), overall survival (OS) and distant metastasis free survival (DMFS).In multivariable analysis, patients with high (≥ median) tumor SUV max (OR 6.3), SUV mean (OR 6.3), MTV (OR 19.0), TLG (OR 19.0), SAM (OR 11.7) and N SAM (OR 19.0) had high pathological T-stage (T3/T4) (p0.05). Ring/heterogeneous pattern on CECT qualitative assessment was associated with worse DMFS and OS.High PET/CT parameters were associated with pathologically advanced T stage (T3/T4). Qualitative assessment of CECT has prognostic value. PET/CT parameters did not predict clinical outcome.

Purpose To assess a new method for generating patient-specific volumetric dose calculations and analyze the relationship between tumor dose and positron emission tomography (PET) response after radioembolization of hepatic melanoma metastases. Methods and Materials Yttrium-90 ( 90 Y) bremsstrahlung single photon emission computed tomography (SPECT)/computed tomography (CT) acquired after 90 Y radioembolization was convolved with published 90 Y Monte Carlo estimated dose deposition kernels to create a three-dimensional dose distribution. Dose-volume histograms were calculated for tumor volumes manually defined from magnetic resonance imaging or PET/CT imaging. Tumor response was assessed by absolute reduction in maximum standardized uptake value (SUV max ) and total lesion glycolysis (TLG). Results Seven patients with 30 tumors treated with 90 Y for hepatic metastatic melanoma with available 90 Y SPECT/CT and PET/CT before and after treatment were identified for analysis. The median (range) for minimum, mean, and maximum dose per tumor volume was 16.9 Gy (5.7–43.5 Gy), 28.6 Gy (13.8–65.6 Gy) and 36.6 Gy (20–124 Gy), respectively. Response was assessed by fluorodeoxyglucose PET/CT at a median time after treatment of 2.8 months (range, 1.2–7.9 months). Mean tumor dose ( P = .03) and the percentage of tumor volume receiving ≥ 50 Gy ( P max , whereas maximum tumor dose predicted for decrease in tumor TLG ( P Conclusions Volumetric dose calculations showed a statistically significant association with metabolic tumor response. The significant dose-response relationship points to the clinical utility of patient-specific absorbed dose calculations for radionuclide therapy.

Purpose To investigate a simple semiquantitative method to estimate yttrium-90 ( 90 Y) dose delivered with radioembolization to infiltrative hepatocellular carcinoma (HCC). Materials and Methods In a prospective study, patients with infiltrative HCC and portal vein thrombosis (PVT) underwent glass-based 90 Y radioembolization including technetium-99m macroaggregated albumin ( 99m Tc-MAA) hepatopulmonary shunt study before therapy and bremsstrahlung single photon emission computed tomography (SPECT)/computed tomography (CT) after 90 Y radioembolization. Baseline magnetic resonance imaging was coregistered with 99m Tc-MAA and bremsstrahlung SPECT/CT imaging separately. Unit tumor activity ( 90 Y radioactivity delivered to each cubic centimeter of tumor) was estimated based on a lobar infusion approach. Correlation between proportions of 99m Tc-MAA and 90 Y delivered to the tumor was investigated. Survival analysis was performed using Kaplan-Meier estimations. Results 90 Y therapy was administered in 18 consecutive patients (median age, 55.3 y; mean tumor volume, 588 cm 3 ). Higher intratumoral 90 Y dose predicted prolonged survival, with 13.2-month median survival in patients with HCC and mean 90 Y dose of ≥ 100 Gy versus 4.6-month median survival for other patients ( P 90 Y dose, 51.9% was delivered to the targeted tumors compared with 74.1% of 99m Tc-MAA with linear correlation between biodistribution of 99m Tc-MAA and 90 Y observed (Pearson r = 0.774, P Conclusions The findings in this study suggest that approximately 50% of administered 90 Y dose is taken up by targeted infiltrative HCC with PVT. Intratumoral 90 Y dose ≥ 100 Gy in unresectable infiltrative HCC via a lobar intraarterial approach is a positive prognostic factor for survival.

We set out to develop normal databases and prospectively validate abnormality criteria for a low-dose Tc-99m tetrofosmin myocardial perfusion SPECT protocol using the 530c CZT camera. All patients received 6 mCi rest/20 mCi stress doses of Tc-99m tetrofosmin. Rest and stress images were obtained over 7-9 and 5-7 minutes according to the chest size. Low-dose CT of the chest was obtained on a standalone CT scanner. Forty patients with very low likelihood (LLK) of coronary artery disease (CAD) were used to define the normal count distributions. The abnormality criteria were prospectively validated in 55 patients who had coronary angiography and in 40 patients with LLK of CAD. The results for quantitative non-attenuation-corrected (AC) and AC analysis and visual analysis were as follows: sensitivity of 79%, 85%, and 92% (P = NS) and specificity of 44%, 75%, and 56% (P = NS), respectively. The normalcy rates for quantitative non-AC and AC analyses and visual analysis were 95%, 98%, and 98% (P = NS). We have developed non-AC and AC normal databases for low-dose rest/stress Tc-99m tetrofosmin myocardial perfusion SPECT protocol using the 530c CZT camera. The per-patient diagnostic performance of quantitative analyses is not significantly different from visual analysis by an experienced reader.

Assessment of benign and malignant lesions of the parotid gland, including metastatic lesions, is challenging with current imaging methods. Fluorine-18 FDG PET/CT is a noninvasive imaging modality that provides both anatomic and metabolic information. Semiquantitative data obtained from PET/CT, also known as PET/CT parameters, are maximum, mean, or peak standardized uptake values (SUVs); metabolic tumor volume; total lesion glycolysis; standardized added metabolic activity; and normalized standardized added metabolic activity. Our aim was to determine whether FDG PET/CT parameters can differentiate benign, malignant, and metastatic parotid tumors.Thirty-four patients with parotid neoplasms underwent PET/CT before parotidectomy; maximum SUV, mean SUV, peak SUV, total lesion glycolysis, metabolic tumor volume, standardized added metabolic activity, and normalized standardized added metabolic activity were calculated on a dedicated workstation. Univariate analyses were performed. A ROC analysis was used to determine the ability of PET/CT parameters to predict pathologically proven benign, malignant, and metastatic parotid gland neoplasms.Fourteen patients had a benign or malignant primary parotid tumor. Twenty had metastases to the parotid gland. When the specificity was set to at least 85% for each parameter to identify cut points, the corresponding sensitivities ranged from 15% to 40%. Assessment of benign versus malignant lesions of parotid tumors, as well as metastasis from squamous cell carcinoma versus other metastatic causes, revealed that none of the PET/CT parameters has enough power to differentiate among these groups.PET/CT parameters, including total lesion glycolysis, metabolic tumor volume, standardized added metabolic activity, and normalized standardized added metabolic activity, are not able to differentiate benign from malignant parotid tumors, primary parotid tumors from metastasis, or metastasis from squamous cell carcinoma and nonsquamous cell carcinoma metastasis.

F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) is known to be a useful diagnostic tool for staging, restaging, and monitoring therapy for lymphoma. The purpose of this retrospective study is to present a spectrum of FDG PET findings at initial presentation of Burkitt lymphoma and subsequent findings after therapy.We retrospectively reviewed 48 patients with Burkitt lymphoma referred for a total of 160 FDG PET/computed tomography (CT) scans at our institution. We characterized the disease distribution of Burkitt lymphoma in all patients and measured representative FDG activity from initial staging scans. Therapeutic response and disease remission were assessed in patients with PET/CT and clinical follow-up studies.Of the 48 patients diagnosed with Burkitt lymphoma, 25 patients had FDG PET/CT scans for initial staging. All untreated lesions of Burkitt lymphoma were highly FDG avid. The mean maximum standardized uptake value of 54 representative lesions is 16.5 (range: 6-54). Twelve patients were immune compromised. The majority of patients had disease localized to the abdomen and the pelvis. Extranodal involvement was identified in more than half of the patients studied.The American (or sporadic) form of Burkitt lymphoma presented with intense hypermetabolic lesions when untreated. The information is useful in evaluating post-treatment studies in the absence of a pretreatment scan.

Christopher L. Hansen, MD, Richard A. Goldstein, MD, Olakunle O. Akinboboye, MBBS, MPH, MBA, Daniel S. Berman, MD, Elias H. Botvinick, MD, Keith B. Churchwell, MD, C. David Cooke, MSEE, James R. Corbett, MD, S. James Cullom, PhD, Seth T. Dahlberg, MD, Regina S. Druz, MD, Edward P. Ficaro, PhD, James R. Galt, PhD, Ravi K. Garg, MD, Guido Germano, PhD, Gary V. Heller, MD, PhD, Milena J. Henzlova, MD, Mark C. Hyun, CNMT, NCT, RT(N)(R), Lynne L. Johnson, MD, April Mann, CNMT, NCT, RT(N), Benjamin D. McCallister, Jr, MD, Robert A. Quaife, MD, Terrence D. Ruddy, MD, Senthil N. Sundaram, MD, MPH, Raymond Taillefer, MD, R. Parker Ward, MD, John J. Mahmarian, MD

Standardized added metabolic (SAM) activity is a functional objective measurement of the total tumoral metabolic activity that avoids partial volume effect and thresholding, which limit conventional PET parameters. The purpose of this study is to investigate the role of SAM in predicting survival in unresectable, chemorefractory colorectal hepatic metastatic disease treated with resin-based Y radioembolization.This is a prospective correlative study of patients with unresectable, chemorefractory colorectal liver metastasis who underwent F-FDG PET/CT and CT/MRI before and after Y. Target RECIST, PERCIST, change in total glycolytic activity (ΔTGA), and ΔSAM treatment response were assessed. Percentage changes in diameter, SUVpeak, TGA, and SAM were calculated pre- and post-Y therapy and objective response was defined as30% change (responders). Survival analysis by Kaplan-Meier, log-rank, and Cox proportional hazard models were performed and significance was set at0.05.Sixteen patients (mean age of 61.6) were enrolled and performed a total of 20 Y therapies. After Y, target ΔSAM showed an objective response rate of 40% vs. 35%, 30%, and 22.2% based on target ΔTGA, PERCIST, and RECIST criteria, respectively. Median overall survival (OS) of the cohort after Y was 9.2 months (CI 95% 2.2-16.2). Patients demonstrating objective response based on ΔSAM had a median OS of 22.7 months (CI 95% 12.4-33.0) vs. 6.7 (CI 95% 4.2-9.2) in non-responders (P = 0.007). On multivariate analysis, hazard ratios for the objective response group based on target ΔSAM were 0.01 (P = 0.03) vs. 0.05 (P = 0.08), 0.20 (P = 0.29), and 0.91 (P = 0.98) based on target ΔTGA, PERCIST, and RECIST criteria, respectively.In unresectable colorectal liver metastatic disease refractory to standard chemotherapy, ΔSAM predicted OS for assessment of response following Y radioembolization therapy, whereas RECIST, PERCIST, and ΔTGA did not.

One of the fundamental quests of nuclear cardiology is the search for elements with appropriate chemical properties for use in radiopharmaceuticals, which have radioactive isotopes that produce photons well suited for imaging, and deliver only a small radiation dose to the patient. This requires that that the emission of any radiation that does not contribute to the image be kept to a minimum and that the isotope remains radioactive only for a short period of time. Understanding the emission of radiation from atoms requires an understanding of atomic and nuclear structure and forces.

Attenuation correction minimizes the impact of body habitus on the acquired myocardial count distribution. The superior diagnostic performance of corrected over uncorrected SPECT images is due to improved specificity and normalcy rate. The transmission image used for attenuation correction is obtained using CT or Gd-153 line sources. Artifactual defects may develop with attenuation correction if the transmission image is truncated, of poor count density, significantly contaminated by downscatter or misregistered with the emission image. Attenuation correction can help decrease the radiation exposure to the patient and improve the workflow in the nuclear laboratory by obviating the need for rest imaging on stress-first myocardial perfusion SPECT protocols. Coronary calcium on the CT attenuation image can add diagnostic and prognostic value to normal myocardial perfusion SPECT in patients without known coronary artery disease. Incidental noncardiac findings of potential clinical relevance are frequently found on the CT attenuation image and should be described on the clinical report.

Nuclear cardiac imaging is solidly based on many branches of science and engineering, including nuclear, optical and mathematical physics, electrical and mechanical engineering, chemistry and biology. This chapter uses principles from these scientific fields to provide an understanding of both the signals used, and the imaging system that captures these signals. Nuclear cardiology’s signals are the x-rays or ?-rays photons emitted from a radioactive tracer and its imaging systems are either single-photon emission computed tomography (SPECT) or positron emission tomography (PET) cameras. This combination has met with remarkable success in clinical cardiology. This success is due to the combination of sophisticated electronic nuclear instruments with a highly specific and thus powerful signal. The signal is as important as or more important than the imaging system. There is a misconception that cardiac magnetic resonance (CMR) cardiac computed tomography (CCT) and echocardiography are superior to nuclear cardiology imaging because of their superior spatial resolution. Yet, in detecting perfusion defects what is really necessary is superior contrast resolution. It is this superior contrast resolution that allows us to differentiate between normal and hypoperfused myocardium facilitating the visual analysis of nuclear cardiology perfusion images. Because these objects are bright compared to the background radioactivity, computer algorithms have been developed that allow us to automatically and objectively process and quantify our images. This chapter explains many of the important scientific principles necessary to understand nuclear cardiology imaging in general, i.e., how these sophisticated imaging systems detect the radiation emitted from the radiotracers.

Primary and metastatic liver cancers are responsible for considerable morbidity and mortality, and many patients are not curable at presentation. Therefore, new therapies such as radioembolization with yttrium 90 ((90)Y)-labeled microspheres are an alternative method to treat patients with unresectable primary or secondary liver tumors. Patient selection, treatment technique, and early recognition of potential complications are the keys for successful patient outcomes. The activity of administered (90)Y microspheres depends on multiple variables, including the tumor burden, the volume of the liver lobe to be treated, the type of (90)Y microspheres, and the hepatopulmonary shunt fraction. Preprocedural planning relies on the results of cross-sectional imaging to determine the extent of disease, tumoral and nontumoral liver volumes, patency of the portal vein, and the degree of extrahepatic disease. A multidisciplinary approach that combines expertise in cross-sectional imaging, nuclear medicine, and flow dynamics is critical to adequately target malignant tissue. Preprocedural multimodality imaging, particularly combined single photon emission computed tomography (SPECT) and computed tomography (CT) imaging (SPECT/CT), may be used to identify nontarget imaging patterns that, if recognized, can potentially be corrected with either branch vessel embolization or catheter repositioning. Postprocedural multimodality imaging is also useful to confirm the appropriate delivery of (90)Y microspheres, enabling early identification of potential complications and the adequacy of microsphere distribution, thereby optimizing planning for subsequent therapies.

The purpose of this study was to assess the value of routine image of the kidneys to detect occult renovascular disease following stress thallium imaging in patients being evaluated for coronary artery disease

OBJECTIVE The aim of this study was to explore the relationship of PET/CT parameters with human papillomavirus (HPV) status of oropharyngeal (OP) and oral cavity (OC) squamous cell carcinomas (SCCs). PATIENTS AND METHODS We retrospectively reviewed 39 patients with OC and OP-SCC who underwent staging 18F-FDG PET/CT. PET/CT parameters were measured for the primary tumor and the hottest involved node, including SUV max, SUV mean, SUV peak, metabolic tumor volume, total lesion glycolysis, standardized added metabolic activity (SAM), and normalized SAM. Patient characteristics were compared between HPV positive (HPV+) and negative (HPV-) groups. Receiver operating characteristic analysis was used to dichotomize PET/CT parameters into high and low. Logistic regression models predicting HPV status were fit for each PET/CT parameter. RESULTS The HPV+ group was composed of 18 patients all with OP-SCC; the HPV- group consisted of 21 patients, 4 OP cancer patients and 17 OC cancer patients. The HPV+ group had a higher proportion of N2 stage (94% vs 43%; P < 0.001). Nodal PET/CT parameters were higher in the HPV+ group (P < 0.01); this difference was not present for the primary lesion. After adjusting for sex and age, the association of higher nodal SUV max (odds ratio [OR], 9.67), SUV mean (OR, 10.48), SUV peak (OR 9.67), metabolic tumor volume (OR, 14.52), total lesion glycolysis (OR, 11.84), and SAM, normalized SAM (OR, 16.21) with HPV+ status remained statistically significant (P < 0.05). CONCLUSIONS Nodal PET/CT parameters predict HPV status. High nodal FDG uptake should raise suspicion for positive HPV status in the evaluation of the primary lesion.

Background Deconvolution of septal penetration (DSP) has been developed to improve quantification so as to allow the use of low-energy high-resolution collimators for iodine 123 cardiac single photon emission computed tomography (SPECT) imaging. The purpose of this study is to optimize its acquisition and processing protocols. Methods and Results Planar images of a 9-compartment phantom loaded with variable radioactive concentrations were acquired to derive optimal scatter compensation scaling factors for 20% and 15% photopeak energy window configurations, respectively. A cardiac phantom, loaded with high and low heart-to-calibration ratios (HCRs), respectively, was imaged with both configurations. Repeated acquisitions were done for medium-energy all-purpose collimators for comparison. Critical frequencies for Butterworth filtering were optimized by use of defect contrast and normal short-axis uniformity as selection indices. HCRs were calculated with planar projection and different reconstruction methods, respectively, and then compared with the true HCRs. SPECT produced more accurate HCRs than planar imaging. With the optimized parameters for scatter compensation and filtering, the 2 energy window configurations yielded similar results. Iterative reconstructions with DSP yielded more accurate HCRs than other reconstructions without DSP. Conclusion The optimized protocols based on DSP show promise that quantification of I-123 cardiac SPECT imaging can be achieved with the widely available low-energy high-resolution collimators.

Background Small–field-of-view (FOV) dedicated cardiac single photon emission computed tomography (SPECT) systems will frequently exhibit severe transmission scan truncation that may degrade attenuation correction (AC). This study evaluated the impact of transmission scan truncation on AC and developed automated transmission scan truncation quality control (ATSTQC) for small-FOV systems. Methods and Results Small-FOV data were simulated from the data of 10 patients acquired by a full-FOV Philips Vertex system. AC images of the full- and small-FOV data were compared by mean and maximum absolute differences of myocardial counts, and differences in stress and rest severity scores were calculated by use of the Emory Cardiac Toolbox.small-FOV systems. ATSTQC was developed to identify critical truncation that significantly increased these indices and then tested with 18 independent patients. Left-side truncation resulted in significant distortion of the quantitative indices. ATSTQC, developed on the condition that left-side truncation is critical, showed high concordance with the qualitative assessment in identification of critical truncation. Conclusions Identification of left-side truncation as critical truncation is necessary to judge whether accurate AC can be obtained. The developed ATSTQC can accurately detect critical truncation and will help clinicians decide whether to use AC in a particular study.

The quality of a Teboroxime single-photon emission computed tomography (SPECT) study can be degraded by Teboroxime's rapid myocardial washout and high liver uptake. Described is the use of fast-fanning acquisition and nonlinear regression with distance penalty (NLRDP) to compensate for the two effects. Tl-201/conventional single-rotation Sestamibi (MIBI) and Tl-201/dynamic fast-fanning Teboroxime (TEBO) rest/stress acquisitions were conducted on 18 subjects. TEBO reconstructions were processed by NLRDP using group-averaged kinetics to separate images into liver, myocardium, and background. Reprojections of these compartments were registered with the measured projections. This made possible the extraction of patient-specific kinetics. NLRDP identified defects (abnormal myocardium with different kinetics from normal tissue) by differences in the kinetics of the defect pixels. Enhanced-TEBO (E-TEBO) images were produced by using the kinetic curves to calculate the Teboroxime concentration in each pixel at the time of expected peak myocardial uptake and by omitting the liver compartment. Stress and reversibility total severity scores and total impaired and reversible myocardial mass were computed for the MIBI, TEBO, and E-TEBO images using the Emory Cardiac Toolbox. Regression and correlation analyses of these quantitative indices indicate that Teboroxime SPECT can produce results similar to those of Sestamibi SPECT if E-TEBO images are generated.

Background Attenuation artifact remains a substantial limitation to confident interpretation of images and reduces laboratory efficiency by requiring comparison of stress and rest image sets. Attenuation-corrected stress-only imaging has the potential to ameliorate these limitations.

Background A gender-independent stress normal database and criteria for abnormality for attenuation-corrected rest-stress technetium 99m sestamibi same-day myocardial perfusion imaging were developed by evaluation of 112 patients, validated against an obese population of 95 patients from four different clinical sites, and compared with conventional gender-matched database quantification of non-attenuation-corrected studies.

Improvements in technology and methods have resulted in a field that is ready to unlock the body's secrets. The advancements reviewed in this article are remarkable. Just ten years ago, SPECT myocardial tomograms exhibited a spatial resolution of close to 2 cm and PET scanners were prohibitively expensive. The instrumentation reviewed can image down to a 1.8 mm spatial resolution, and high-performance PET scanners and PET/SPECT cameras are being routinely sold for one-third the cost of the high-end PET scanners of ten years ago. These gains, coupled with the relative ease of developing positron-emitting radiopharmaceuticals, opens a new chapter in physiologic imaging. Add to this that these modalities are inherently digital, facilitating their progress in totally automatic analysis; multidimensional, multimodality display; and computer-assisted image interpretation by the use of AI techniques. The result is a field poised to unlock the secrets of the body's functions, when the only limitation is one's own imagination and the number of scientists working to bring it to its full potential.

Nuclear cardiology imaging is solidly based on many branches of science and engineering, including nuclear, optical, and mathematical physics; electrical and mechanical engineering; chemistry; and biology. This chapter uses principles from these scientific fields to provide an understanding of both the signals used and the imaging system that captures these signals. These principles have been simplified to fit the scope of this atlas.

The quality field of view (QFOV) of a GE Healthcare Discovery NM 530c cardiac single-photon emission computed tomograph (D530c) is the volume representing the intersection of the 19 conic volumes defined by the system's 19 pinhole/detectorarray pairs. Here are reported phantom experiments conducted to investigate and characterize aspects of the D530c QFOV.