National myeloma patient survey shows continuing inappropriate imaging and geographical inequalities.

OBJECTIVE: To evaluate the provision of imaging at diagnosis of myeloma from the service user perspective with a specific focus on how the experiences of patients align with the National Institute for Health and Care Excellence (NICE) guidelines (NG35, 2016) on first-line imaging practice for myeloma in the United Kingdom. METHODS: A national survey was performed to evaluate access to imaging from the patient's perspective. Patients with myeloma who received their diagnosis between 2017 and March 2022 were invited to participate. Data were collected using an online survey from 895 patients and carers between 4 and 14 March 2022. RESULTS: Most patients had more than one imaging test. First-line MRI was used in 69.2% of respondents. First-line skeletal survey (SS, whole body X-rays) remained common (48.7% of respondents). 18F-fluorodexyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) was used least often (23.1% of respondents). SS was used more often in East England (57.9%) and Scotland (61.2%) than in South East England (36.3%). CONCLUSIONS: Despite NICE recommendations, first-line MRI was not used in a third of patients surveyed, with geographical variation in imaging practice. Patients are still undergoing multiple imaging tests at diagnosis. Healthcare professionals should continue to emphasize the superiority of MRI compared to SS to drive for improvements in care. ADVANCES IN KNOWLEDGE: Current recommendations on first-line imaging for myeloma are not provided consistently across the United Kingdom. There is a need to drive change and support healthcare professionals to deliver guidance-based recommendations to improve experience and outcomes for patients.

Sociodemographic factors and Child Opportunity Index disparities associated with missed care opportunities in pediatric patients with lymphoma and leukemia referred for FDG-PET/CT.

BACKGROUND: Little data exists on the association of missed care opportunities (MCOs) in children referred for nuclear medicine/nuclear oncology imaging examinations and socioeconomic disparities. OBJECTIVE: To determine the prevalence of MCOs in children with lymphoma/leukemia scheduled for fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) and the impact of sociodemographic factors and Child Opportunity Index (COI). MATERIALS AND METHODS: Retrospective analysis of MCOs in children with lymphoma/leukemia scheduled for FDG-PET/CT (2012 to 2022) was performed. In univariate analysis, patient, neighborhood, and appointment data were assessed across MCOs and completed appointments. Logistic regression evaluated independent effects of patient-, neighborhood-, and appointment-level factors with MCOs. Two-sided P-value < .05 was considered statistically significant. RESULTS: In 643 FDG-PET/CT appointments (n = 293 patients; median age 15 years (IQR 11.0-17.0 years); 37.9% female), there were 20 MCOs (3.1%) involving 16 patients. Only 8.2% appointments involved Black/African American non-Hispanic/Latino patients, yet they made up a quarter of total MCOs. Patients living in neighborhoods with very low or low COI experienced significantly higher MCOs versus zip codes with very high COI (6.9% vs. 0.8%; P = 0.02). Logistic regression revealed significantly increased likelihood of MCOs for patients aged 18 to 21 [odds ratio (OR) 4.50; 95% CI 1.53-13.27; P = 0.007], Black/African American non-Hispanic/Latino (OR 3.20; 95% CI 1.08-9.49; P = 0.04), zip codes with very low or low COI (OR 9.60; 95% CI 1.24-74.30; P = 0.03), and unknown insurance status. CONCLUSION: Children with lymphoma/leukemia, living in zip codes with very low or low COI, and who identified as Black/African American non-Hispanic/Latino experienced more MCOs. Our study supports the need to address intersecting sociodemographic, neighborhood, and health system factors that will improve equitable access to necessary healthcare imaging for children.

Discordant results in 18F-FDG PET/CT and ultrasound-based assessment for axillary lymph node metastasis detection: A large retrospective analysis in 560 patients with breast cancer.

PURPOSE: Ultrasound is the recommended modality to assess axillary lymph node involvement in breast cancer; nevertheless, 18F-fluorodeoxyglucose (18F-FDG) integrated positron emission tomography/computed tomography (PET/CT) diagnostic efficiency, to identify suspicious lesions, is also considered. We aim to report discrepancies in ultrasound and 18F-FDG PET/CT results. METHODS: This single-centered retrospective analysis selected consecutive patients with invasive ductal biopsy-proven breast cancer, for whom divergent 18F-FDG PET/CT and axillary ultrasound imaging (and/or core needle biopsy if available) had been performed, and described clinical, histological, imaging, and surgery data. RESULTS: This retrospective study included 560 patients and identified discordant results between 18F-FDG PET/CT and ultrasound (suspicious 18F-FDG PET/CT and normal ultrasound imaging and/or core needle biopsy) in 20 (4%) patients. Axillary lymph node involvement was confirmed in 17 (85%) out of these 20 patients. Further, the lymph nodes were smaller than one centimeter in 12 (60%) patients, macrometastasic involvement (involvement >2 mm) was detected in 13 (65%) patients, and more than 3 macrometastases were detected in 6 (30%) patients. All patients had an aggressive breast cancer. The sentinel node biopsy performed in 9 (45%) patients allowed to reveal lymph node involvement, even in cases of macrometastatic involvement. CONCLUSION: Discordant results were issued from normal ultrasound imaging and/or core needle biopsy, and suspicious 18F-FDG PET/CT revealed that 18F-FDG PET/CT may overcome axillary ultrasound limits in the specific case of aggressive breast cancers, especially for axillary lymph nodes smaller than 1 centimeter. Sentinel node biopsy remains a valuable aid, even in patients with macrometastatic involvement.

Reproducibility and Repeatability of Assessment of Myocardial Light Chain Amyloidosis Burden Using 18F-Florbetapir PET/CT.

BACKGROUND: 18F-florbetapir PET is emerging as an excellent quantitative tool to quantify cardiac light chain (AL) amyloidosis burden. The primary aim of this study was to determine interobserver reproducibility and intraobserver repeatability, defined per the recommendations of the Quantitative Imaging Biomarker Alliance technical performance group, of PET 18F-florbetapir retention index (RI) in patients with cardiac AL amyloidosis. METHODS: The study cohort comprised 37 subjects with systemic AL amyloidosis enrolled in the prospective study: Molecular Imaging of Primary Amyloid Cardiomyopathy (clinical trials.gov NCT: 02641145). Using 10 mCi of 18F-florbetapir, a 60-minute dynamic cardiac scan was acquired. Global and segmental left ventricular estimates of retention index (RI) of 18F-florbetapir were calculated (Carimas 2.9 software, Turku, Finland). RI was analyzed twice, at least 24 hours apart, by two independent observers. Intraobserver repeatability and interobserver reproducibility were evaluated using Bland-Altman plots and scatter plots with fitted linear regression curves. RESULTS: All reproducibility (interobserver, r = 0.98) and repeatability (intraobserver, R=0.99 for each observer) measures of 18F-florbetapir RI are excellent. On the Bland-Altman plots, the agreement limits for global 18F-florbetapir RI were high and ranged for reproducibility (interobserver) from - 9.3 to + 9.4% (Fig. 1), and for repeatability (observer 1 from - 10.8 to + 10.7% and from - 9.2 to + 11.4%, for observer 2). CONCLUSIONS: The present study showed excellent interobserver reproducibility and intraobserver repeatability of 18F-florbetapir PET retention index in patients with cardiac AL amyloidosis.

Assessment of cardiac tumors by 18F-FDG PET/CT imaging: Histological correlation and clinical outcomes.

BACKGROUND: To evaluate the diagnostic value of 18F-FDG PET/CT in distinguishing benign versus malignant cardiac tumors as well as to assess its prognostic value. METHODS: We analyzed 38 patients with cardiac tumors who underwent 18F-FDG PET/CT and followed for median 8.5 ± 12.5 months. SUVmax and TBRmax (maximum tumor-to-background ratio) by receiver-operating characteristic (ROC) curve analysis were used to obtain threshold for the diagnosis of malignancy as defined by histology (n = 38). Survival was assessed and correlated with the dignity of the lesions and PET parameters. RESULTS: Optimal cut-off values indicating malignancy were as follows: SUVmax = 3.44, with 100% sensitivity and 92.9% specificity, and TBRmax = 1.55, with 95.8% sensitivity and 92.9% specificity. A significant difference of 18F-FDG uptake was observed between primary benign (n = 14, SUVmax = 2.35 ± 1.31, TBRmax = 1.05 ± 0.50) compared to primary malignant cardiac tumors (n = 11, SUVmax = 8.90 ± 4.23, TBRmax = 3.82 ± 1.44) as well as cardiac metastases and lymphoma (n = 13, SUVmax = 14.37 ± 8.05, TBRmax = 6.19 ±  3.38) (all P < .001). Survival rate was significantly lower in patients with malignant as compared to benign cardiac tumors (P < .05). Regression analysis revealed that the lesion dignity determined by the cut-off value of SUVmax was an independent predictor for death in patients with cardiac tumors (P < .05). CONCLUSION: 18F-FDG uptake in cardiac tumors can differentiate between benign and malignant cardiac tumors and predicts survival.

Multi-observer concordance and accuracy of the British Thoracic Society scale and other visual assessment qualitative criteria for solid pulmonary nodule assessment using FDG PET-CT.

AIM: To compare the interobserver reliability and diagnostic accuracy of the British Thoracic Society (BTS) scale and other visual assessment criteria in the context of 2-[18F]-fluoro-2-deoxy-d-glucose (FDG) positron-emission tomography (PET)-computed tomography (CT) evaluation of solid pulmonary nodules (SPNs). MATERIALS AND METHODS: Fifty patients who underwent FDG PET-CT for assessment of a SPN were identified. Seven reporters with varied experience at four centres graded FDG uptake visually using the British Thoracic Society (BTS) four-point scale. Five reporters also scored SPNs according to three- and five-point visual assessment scales and using semi-quantitative assessment (maximum standardised uptake value [SUVmax]). Interobserver reliability was assessed with the intra-class correlation coefficient (ICC) and weighted Cohen's kappa (κ). Diagnostic performance was evaluated by receiver operator characteristic (ROC) analysis. RESULTS: Good interobserver reliability was demonstrated with the BTS scale (ICC=0.78, 95% confidence interval [CI]: 0.69-0.85) and five-point scale (ICC=0.78, 95 CI 0.68-0.86), whilst the three-point scale demonstrated moderate reliability (ICC=0.70, 95% CI: 0.59-0.80). Almost perfect agreement was achieved between two consultants (κ=0.85), and substantial agreement between two other consultants (κ=0.78) using the BTS scale. ROC curves for the BTS and five-point scales demonstrated equivalent accuracy (BTS area under the ROC curve [AUC]=0.768; five-point AUC=0.768). SUVmax was no more accurate compared to the BTS scale (SUVmax AUC=0.794; BTS AUC=0.768, p=0.43). CONCLUSIONS: The BTS scale can be applied reliably by reporters with varied levels of PET-CT reporting experience, across different centres and has a diagnostic performance that is not surpassed by alternative scales.

The quantitative assessment of interstitial lung disease with positron emission tomography scanning in systemic sclerosis patients.

OBJECTIVES: The reversibility of interstitial lung disease (ILD) in SSc is difficult to assess by current diagnostic modalities and there is clinical need for imaging techniques that allow for treatment stratification and monitoring. 18F-Fluorodeoxyglucose (FDG) PET/CT scanning may be of interest for this purpose by detection of metabolic activity in lung tissue. This study aimed to investigate the potential role of 18F-FDG PET/CT scanning for the quantitative assessment of SSc-related active ILD. METHODS: 18F-FDG PET/CT scans and high resolution CT scans of eight SSc patients, including five with ILD, were analysed. For comparison, reference groups were included: eight SLE patients and four primary Sjögren's syndrome (pSS) patients, all without ILD. A total of 22 regions of interest were drawn in each patient at apical, medial and dorsobasal lung levels. 18F-FDG uptake was measured as mean standardized uptake value (SUVmean) in each region of interest. Subsequently, basal/apical (B/A) and medial/apical (M/A) ratios were calculated at patient level (B/A-p and M/A-p) and at tissue level (B/A-t and M/A-t). RESULTS: SUVmean values in dorsobasal ROIs and B/A-p ratios were increased in SSc with ILD compared with SSc without ILD (P = 0.04 and P = 0.07, respectively), SLE (P = 0.003 and P = 0.002, respectively) and pSS (P = 0.03 and P = 0.02, respectively). Increased uptake in the dorsobasal lungs and increased B/A-t ratios corresponded to both ground glass and reticulation on high resolution CT. CONCLUSION: Semi-quantitative assessment of 18F-FDG PET/CT is able to distinguish ILD from non-affected lung tissue in SSc, suggesting that it may be used as a new biomarker for SSc-ILD disease activity.

Fluorodeoxyglucose positron emission tomography/computed tomography in the diagnosis, assessment of disease activity and therapeutic response in relapsing polychondritis.

OBJECTIVE: To evaluate 18F-fluorodeoxyglucose (FDG) PET/CT in the assessment of disease activity, extent of the disease and response to therapy in relapsing polychondritis. METHODS: Twenty-five patients (9 men, 16 women) with a mean age of 38.2 years (s.d. 13.7; range 18-62), diagnosed to have relapsing polychondritis according to Damiani and Levine's modification of McAdam's criteria, who underwent PET/CT examination were included. Ten patients underwent a second PET/CT examination after therapy or during follow-up. Clinical symptoms and auxiliary examination findings were recorded. PET/CT findings were reviewed and correlated with the clinical symptoms. RESULTS: The major symptoms were aural pain (n = 21), nasal pain (n = 10), stridor (n = 5), cough (n = 9), fever (n = 8) and laryngeal tenderness (n = 8). The initial PET/CT was positive in 23/25 patients. PET/CT revealed involvement of auricular (n = 14), nasal (n = 8), laryngeal (n = 7), tracheobronchial (n = 6) and Eustachian (n = 3) cartilages with a mean maximum standardized uptake value (SUVmax) of 4.1 (s.d. 2.5; range 1.7-12.7). Fair correlation of aural/nasal pain/stridor with FDG avidity of cartilage involvement on PET/CT was noted. The key finding was detection of asymptomatic large airway involvement in seven patients (28%). Re-examination PET in 10 patients revealed complete therapeutic response (n = 5), partial response (n = 1), stable disease (n = 1), progressive disease (n = 1) and disease recurrence (n = 2). CONCLUSION: FDG PET/CT is a useful tool for the assessment of the disease activity and extent. It identified activity in clinically inaccessible sites that are of clinical significance. It is also useful in assessing treatment response and finding relapse.

RESISTing the Need to Quantify: Putting Qualitative FDG-PET/CT Tumor Response Assessment Criteria into Daily Practice.

Tumor response assessments are essential to evaluate cancer treatment efficacy and prognosticate survival in patients with cancer. Response criteria have evolved over multiple decades, including many imaging modalities and measurement schema. Advances in FDG-PET/CT have led to tumor response criteria that harness the power of metabolic imaging. Qualitative PET/CT assessment schema are easy to apply clinically, are reproducible, and yield good prognostic results. We present 3 such criteria, namely, the Lugano classification for lymphoma, the Hopkins criteria, and the Neck Imaging Reporting and Data Systems criteria for head and neck cancers. When comparing baseline PET/CTs with interim or end-of-treatment PET/CTs, radiologists can classify the tumor response as complete metabolic response, partial metabolic response, no metabolic response, or progressive disease, which has important implications in directing further cancer management and long-term patient prognosis. The purpose of this article is to review the progression of tumor response assessments from CT- and PET/CT-based quantitative and semi-quantitative systems to PET/CT-based qualitative systems; introduce the classification schema for these systems; and describe how to use these rapid, powerful, and qualitative PET/CT-based systems in daily practice through illustrative cases.

Frequency, Determinants, and Costs of Recommendations for Additional Imaging in Clinical 18F-FDG PET/CT Reports.

Our purpose was to determine the frequency, determinants, and costs of recommendations for additional imaging (RAIs) in clinical 18F-FDG PET/CT reports. Methods: This retrospective study included a random sample of 2,643 18F-FDG PET/CT scans that were performed for various clinical reasons at a tertiary-care academic medical center without financial incentives for self-referral, within a 1.5-y period. Results: Ninety-eight (3.7%) of 2,643 18F-FDG PET/CT reports contained an RAI. None of the investigated variables (patient age, hospital status [inpatient or outpatient], indication for 18F-FDG PET/CT scanning [oncologic, infection/inflammation, or miscellaneous], type of 18F-FDG PET/CT scan [low-dose 18F-FDG PET/CT or low-dose 18F-FDG PET/CT combined with diagnostic CT of any body region], or years of experience of the [most senior] signing author) was univariately associated with the presence of an RAI in the 18F-FDG PET/CT report. The hypothesis that RAIs more frequently occur when the anatomic area to which the RAI relates is not covered by a diagnostic CT scan (as part of the 18F-FDG PET/CT examination) was also rejected (P = 0.419). The total costs of all RAIs (regardless of whether they were actually performed by the referring clinicians) were €23,922.21 ($27,065.47), which corresponds to an average of €9.08 ($10.27) RAI costs per 18F-FDG PET/CT exam. The total costs of all RAIs that were actually performed by the referring clinicians were €16,498.62 ($18,666.46), which corresponds to an average of €6.26 ($7.08) RAI costs per 18F-FDG PET/CT exam. Conclusion: RAIs in 18F-FDG PET/CT reports in a European tertiary-care academic medical center without financial incentives for self-referral are infrequent, cannot be anticipated, and result in relatively low overall costs.

Assessment of skeletal tumour burden on 18F-NaF PET/CT using a new quantitative method.

PURPOSE: The purpose of this study was to test a method of quantifying skeletal tumour burden with F-NaF PET/CT. PATIENTS AND METHODS: We retrospectively reviewed the charts of 117 patients who underwent F-NaF PET/CT for the detection of bone metastases, 68 women and 49 men, 16-82 years old (mean±SD: 62.9±10.7 years). Mean standardized uptake values (SUVmean) were measured in five anatomic sites to evaluate normal skeleton activity. The influence of sex and age was investigated. Skeletal tumour burden was calculated in 69 exams positive for bone metastases using volumetric data and SUVmean values. Intraobserver and interobserver reproducibility was tested. In 10 patients with breast cancer, skeletal tumour burden in pretreatment and post-treatment F-NaF PET/CT was compared with tumour marker and clinical evolution. RESULTS: The range of normal skeleton SUVmean for the 410 volume of interests analysed was 2.2-5.9 (mean±SD: 4.4±1.5). A threshold of 10 was chosen to exclude F-NaF normal skeleton uptake. An inverse relationship was found between normal skeleton SUVmean and age (r=-0.237; P=0.032). Our results show excellent intraobserver and interobserver reproducibility, with intraclass correlation values of 0.995 and 0.997, respectively. The percentage change in the skeletal tumour burden in response to therapy shows a moderate direct correlation with the percentage variation of the tumour marker (r=0.668; P=0.035). CONCLUSION: The methodology that we used to quantify skeletal tumour burden is easy to perform, highly reproducible and allows for the evaluation of bone tumour response to therapy in a subgroup of breast cancer patients. The possibility of skeletal tumour burden quantification is another advantage of F-NaF PET/CT over the visual and subjective interpretation of bone scintigraphy.

Pediatric Hodgkin Lymphoma: Predictive value of interim 18F-FDG PET/CT in therapy response assessment.

We investigated the prognostic value of interim F-FDG PET/CT (PET-2) in pediatric Hodgkin lymphoma (pHL), evaluating both visual and semiquantitative analysis.Thirty pHL patients (age ≤16) underwent serial F-FDG PET/CT: at baseline (PET-0), after 2 cycles of chemotherapy (PET-2) and at the end of first-line chemotherapy (PET-T). PET response assessment was carried out visually according to the Deauville Score (DS), as well as semiquantitatively by using the semiquantitative parameters reduction from PET-0 to PET-2 (ΔΣSUVmax0-2, ΔΣSUVmean0-2). Final clinical response assessment (outcome) at the end of first-line chemotherapy was the criterion standard, considering patients as responders (R) or nonresponders (NR). Disease status was followed identifying patients with absence or relapsed/progression disease (mean follow-up: 24 months, range 3-78).Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of visual and semiquantitative assessment were calculated; furthermore, Fisher exact test was performed to evaluate the association between both visual and semiquantitative assessment and outcome at the end of the first-line chemotherapy. The prognostic capability of PET-2 semiquantitative parameters was calculated by ROC analysis and expressed as area under curve (AUC). Finally, progression-free survival (PFS) was analyzed according to PET-2 results based on the 5-point scale and semiquantitative criteria, using the Kaplan-Meier method.Based on the outcome at the end of first-line chemotherapy, 5 of 30 patients were NR, the remnant 25 of 30 were R. Sensitivity, specificity, PPV, NPV, and accuracy of visual analysis were 60%,72%,30%,90%,70%; conversely, sensitivity, specificity, PPV, NPV, and accuracy of semiquantitative assessment were 80%, 92%, 66.7%, 95.8%, 90%. The highest AUC resulted for ΔΣSUVmax0-2 (0.836; cut-off <12.5; sensitivity 80%; specificity 91%). The association between ΔΣSUVmax0-2 and outcome at the end of first-line chemotherapy resulted to have a strong statistical significance (P = 0.0026). Both methods demonstrated to influence PFS, even if the semiquantitative assessment allowed a more accurate identification of patients with a high risk of treatment failure (P = 0.005).Our preliminary results showed that PET-2 visual assessment, by using Deauville criteria, can be improved by using the semiquantitative analysis. The SUV max reduction (ΔΣSUVmax0-2) evaluation might provide a support for the interpretation of intermediate scores, predicting with good confidence those patients who will have a poor outcome and require alternative therapies.

The Value of FDG PET/CT in Treatment Response Assessment, Follow-Up, and Surveillance of Lung Cancer.

OBJECTIVE: The purpose of this article is to summarize the evidence regarding the role of FDG PET/CT in treatment response assessment and surveillance of lung cancer and to provide suggested best practices. CONCLUSION: FDG PET/CT is a valuable imaging tool for assessing treatment response for patients with lung cancer, though evidence for its comparative effectiveness with chest CT is still evolving. FDG PET/CT is most useful when there is clinical suspicion or other evidence for disease recurrence or metastases. The sequencing, cost analysis, and comparative effectiveness of FDG PET/CT and conventional imaging modalities in the follow-up setting need to be investigated.

Inappropriateness of diagnostic imaging examinations in the inpatient setting: a case study research.

OBJECTIVE: The purpose of our study was to audit the clinical appropriateness of the prescriptions of whole body CT (WB-CT), PET-CT and chest X-rays (CXRs) performed at Tor Vergata University Hospital in the inpatient setting. MATERIALS AND METHODS: WB-CT, PET-CT and CXRs examinations were retrospectively analysed in the period between January and December 2014. CXR examinations were divided into bedside CXRs and traditional CXRs. The appropriateness of the examinations was defined according the American College of Radiology Appropriateness Criteria. Inappropriate examinations were divided into six inappropriateness categories in accordance with the European Union Medical Imaging Guidelines. RESULTS: Appropriateness was suboptimal for all analysed techniques CXRs (A = 38%, I = 62%); bedside CXRs (A = 45%, I = 53%); WB-CT (A = 45%, I = 55%); PET-CT (A = 48%, I = 52%). With respect to WB-CT the highest rate of inappropriate imaging prescriptions came from the haematology clinical operative unit (OU) (44%) and emergency medicine (33%); with respect to PET-CT, the thoracic surgery OU (53%) and haematology OU (48%) showed the most inappropriate prescriptions. For CXRs, the percentage of inappropriateness was consistently distributed among all surgical OUs. For bedside CXRs, the largest inappropriate prescribers were the emergency medicine OU (48%), the cardiac surgery OU (58%), the intensive care OU (67%) and anaesthesia resuscitation OU (78%). The most represented classes of inappropriateness were 2, 3, 4 and 6. CONCLUSIONS: The elimination of inappropriate prescriptions would result in an annual savings of approximately 390,000 Euro. An implementation plan to increase prescription appropriateness is under development by our group.

The Impact That Number of Analyzed Metastatic Breast Cancer Lesions Has on Response Assessment by 18F-FDG PET/CT Using PERCIST.

UNLABELLED: The PET Response Criteria in Solid Tumors (PERCIST) are not specific regarding the number of lesions that should be analyzed per patient. This study evaluated how the number of analyzed lesions affects response assessment in metastatic breast cancer. METHODS: In 60 patients, response was assessed by the change in SUVpeak, normalized to lean body mass, of the most (18)F-FDG-avid lesion (PERCIST 1) and by the change in the sum of normalized SUVpeak for up to 5 lesions (PERCIST 5). The correlation between response by PERCIST and progression-free and disease-specific survival was evaluated. RESULTS: In responders and nonresponders, the respective progression-free survival at 2 y was 37.26% and 6.43% for PERCIST 1 (P < 0.0001) and 33.65% and 7.14% for PERCIST 5 (P < 0.0001) and the respective disease-specific survival at 4 y was 58.96% and 25.44% for PERCIST 1 (P < 0.012) and 59.12% vs 20.01% for PERCIST 5 (P < 0.002). CONCLUSION: The number of analyzed lesions does not appear to have a major impact on the prognostic value of response assessment with (18)F-FDG PET/CT in metastatic breast cancer.

18-Month Performance Assessment of Gemini TF 16 PET/CT System in a High-Volume Department.

UNLABELLED: Acceptance testing is a set of quality control tests performed to verify various manufacturer-specified parameters before a newly installed PET/CT system can be accepted for clinical use. A new PET/CT system, Gemini TF 16, installed in our department in September 2012 has a PET component capable of time-of-flight imaging using lutetium-yttrium-oxyorthosilicate crystals and operates in 3-dimensional mode. Our aim was to evaluate the system before acceptance and observe the consistency of its performance during high-volume work for 18 mo after installation (we perform an average of 30 PET/CT scans daily). METHODS: We performed NEMA (National Electrical Manufacturers Association) NU-2 2007 acceptance testing on the Gemini TF 16; continuously evaluated its gain calibration, timing resolution, and energy resolution during the subsequent 18 mo; and analyzed the results. RESULTS: The system passed the acceptance testing and showed few fluctuations in energy and timing resolutions during the observation period. CONCLUSION: The Gemini TF 16 whole-body PET/CT system performed excellently during the 18-mo study period despite the high volume of work.