Impact of 18F-FDG PET Used After Initial Treatment of Cancer: Comparison of the National Oncologic PET Registry 2006 and 2009 Cohorts

Inflammatory and immunopathological differences in brains of permissive and non-permissive hosts with Angiostrongylus cantonensis infection can be identified using 18F/FDG/PET-imaging

BACKGROUND

Angiostrongylus cantonensis is a parasite that mainly infects the heart and pulmonary arteries of rats and causes human eosinophilic meningitis or meningoencephalitis in certain geographical areas. Current diagnostic methods include detection of the parasite in cerebrospinal fluid (CSF) and eosinophilic immune examination after lumbar puncture, which may be risky and produce false-positive results. 18F- Fluorodeoxyglucose (FDG), a Positron emission tomography (PET) tracer, has been used to assess different pathological or inflammatory changes in the brains of patients. In this study, we hypothesized that A. cantonensis infection-induced inflammatory and immunomodulatory factors of eosinophils result in localized pathological changes in the brains of non-permissive hosts, which could be analyzed using in vivo 18F-FDG PET imaging.

METHODOLOGY/FINDINGS

Non-permissive host ICR mice and permissive host SD rats were infected with A. cantonensis, and the effects of the resulting inflammation on 18F-FDG uptake were characterized using PET imaging. We also quantitatively measured the distributed uptake values of different brain regions to build an evaluated imaging model of localized neuropathological damage caused by eosinophilic inflammation. Our results showed that the uptake of 18F-FDG increased in the cerebellum, brainstem, and limbic system of mice at three weeks post-infection, whereas the uptake in the rat brain was not significant. Immunohistochemical staining and western blotting revealed that Iba-1, a microglia-specific marker, significantly increased in the hippocampus and its surrounding area in mice after three weeks of infection, and then became pronounced after four weeks of infection; while YM-1, an eosinophilic chemotactic factor, in the hippocampus and midbrain, increased significantly from two weeks post-infection, sharply escalated after three weeks of infection, and peaked after four weeks of infection. Cytometric bead array (CBA) analysis revealed that the expression of TNF in the serum of mice increased concomitantly with the prolongation of infection duration. Furthermore, IFN-γ and IL-4 in rat serum were significantly higher than in mouse serum at two weeks post-infection, indicating significantly different immune responses in the brains of rats and mice. We suggest that 18F-FDG uptake in the host brain may be attributed to the accumulation of large numbers of immune cells, especially the metabolic burst of activated eosinophils, which are attracted to and induced by activated microglia in the brain.

CONCLUSIONS

An in vivo 18F-FDG/PET imaging model can be used to evaluate live neuroinflammatory pathological changes in the brains of A. cantonensis-infected mice and rats.

PET/NIR Fluorescence Bimodal Imaging for Targeted Tumor Detection

Cancer is one of the greatest threats to human health due to late diagnosis and incomplete resection. The bimodal probe combines positron emission tomography (PET) imaging for noninvasive whole-body scanning with intraoperative near-infrared fluorescence (NIRF) surgical guidance for preoperative tumor detection, tumor resection during surgery, and postoperative monitoring. We developed a new PET/NIRF bimodal imaging agent, [68Ga]Ga-DOTA-NPC, covalently coupled to DCDSTCY and DOTA via ethylenediamine and radiolabeled with gallium-68, and investigated it in vitro and in vivo. The probe was found to be preferential for colon cancer cells due to the organic anion-transporting polypeptide1B3 (OATP1B3). PET/NIRF imaging allowed us to confirm [68Ga]Ga-DOTA-NPC as a promising probe for tumor detection, as it provides good biosafety and high-contrast tumor accumulation. Orthotopic and subcutaneous colon tumors were successfully resected under real-time NIRF guidance. [68Ga]Ga-DOTA-NPC provides highly sensitive and unlimited tissue-penetrating PET/NIRF imaging, helping to visualize and differentiate tumors from adjacent tissue.

Impact of 18 F-FDG PET on the Management in Patients With Recurrent Gynecologic cancer : A Meta-analysis

PURPOSE

Gynecological cancer is the most prevalent cancer among women worldwide. We performed a meta-analysis to assess the impact of 18 F-FDG PET on the management of patients with recurrent gynecological cancers, including cervical, uterine, and ovarian cancers.

METHODS

We systematically searched MEDLINE and EMBASE databases for English-language publications. All published studies on the impact of PET scans on the management of patients with recurrent gynecological cancers were reviewed. The proportion of management change (%), defined as the percentage of patients whose management changed after FDG PET to those who underwent FDG PET, was calculated. The data from each study were analyzed using MedCalc Statistical Software version 14.12.0 (MedCalc Software, Ostend, Belgium).

RESULTS

Nineteen studies including 6191 patients were eligible for inclusion. The impact of FDG PET scan for detecting recurrence/metastasis in patients with gynecologic cancer was evaluated using management change rates, ranging from 9.4% to 60.7% with a pooled effect of 42.0% (95% confidence interval [CI], 34.5%-49.6%; I2 = 92.9%). In the subtype analysis, FDG PET scanning resulted in changes in the management in 48.5% (95% CI, 37.8%-59.3%; I2 = 67.8%) of cervical cancer, 34.7% (95% CI, 33.4%-36.0%; I2 = 0%) of uterine cancer, and 40.3% (95% CI, 26.7%-54.7%; I2 = 95.2%) of ovarian cancer cases.

CONCLUSIONS

FDG PET has a significant impact on the restaging of patients with gynecological cancer. These findings suggest that FDG PET should be performed, especially in cases of suspected recurrence/metastasis in the main gynecologic cancer types, including cervical, ovarian, and uterine cancers.

Diagnosis of Glioblastoma by Immuno-Positron Emission Tomography

Simple Summary

Neuroimaging has transformed the way brain tumors are diagnosed and treated. Although different non-invasive modalities provide very helpful information, in some situations, they present a limited value. By merging the specificity of antibodies with the resolution, sensitivity, and quantitative capabilities of positron emission tomography (PET), “Immuno-PET” allows us to conduct the non-invasive diagnosis and monitoring of patients over time using antibody-based probes as an in vivo, integrated, quantifiable, 3D, full-body “immunohistochemistry”, like a “virtual biopsy”. This review provides and focuses on immuno-PET applications and future perspectives of this promising imaging approach for glioblastoma.

Abstract

Neuroimaging has transformed neuro-oncology and the way that glioblastoma is diagnosed and treated. Magnetic Resonance Imaging (MRI) is the most widely used non-invasive technique in the primary diagnosis of glioblastoma. Although MRI provides very powerful anatomical information, it has proven to be of limited value for diagnosing glioblastomas in some situations. The final diagnosis requires a brain biopsy that may not depict the high intratumoral heterogeneity present in this tumor type. The revolution in “cancer-omics” is transforming the molecular classification of gliomas. However, many of the clinically relevant alterations revealed by these studies have not yet been integrated into the clinical management of patients, in part due to the lack of non-invasive biomarker-based imaging tools. An innovative option for biomarker identification in vivo is termed “immunotargeted imaging”. By merging the high target specificity of antibodies with the high spatial resolution, sensitivity, and quantitative capabilities of positron emission tomography (PET), “Immuno-PET” allows us to conduct the non-invasive diagnosis and monitoring of patients over time using antibody-based probes as an in vivo, integrated, quantifiable, 3D, full-body “immunohistochemistry” in patients. This review provides the state of the art of immuno-PET applications and future perspectives on this imaging approach for glioblastoma.

Impact of Follow-up 18F-FDG PET on the Management in Patients With Lung Cancer: A Meta-analysis

PURPOSE

The incidence of lung cancer has increased steadily. We meta-analyzed to assess the impact of 18F-FDG PET on the management of lung cancer to detect recurrence/metastasis.

MATERIALS AND METHODS

We performed systematic searches of Medline and Embase databases for English-language publications. All published studies regarding the impact of PET on the management of patients with lung cancer in detection of recurrence/metastasis were searched. The proportion of management change (%) defined as the percentage of patients who changed management after FDG PET to patients who had FDG PET was calculated. The data from each study were analyzed using MedCalc Statistical Software version 14.12.0 (MedCalc Software, Ostend, Belgium).

RESULTS

Eight studies including 523 patients were eligible for inclusion in the study. The impact of 18F-FDG PET for the purpose of detecting recurrence/metastasis in patients with lung cancer was evaluated using management change rates, which were ranged from 28.6% to 79.2% with a pooled effect of 61.4% (95% confidence interval, 49.5%-72.7%; I2 = 85.7%). In a subgroup analysis, impact of 18F-FDG PET was evaluated in studies of patients with non-small cell lung cancer with indication of abnormal findings of conventional imaging, elevated tumor markers, and clinical symptoms with the pooled rate of management change of 62.2% (95% confidence interval, 44.2%-78.5%; I2 = 88.0%).

CONCLUSIONS

We have highlighted that 18F-FDG PET has a major impact on the management of patients with recurrent lung cancer. These findings suggest that 18F-FDG PET should be performed in patients with lung cancer, especially in cases involving equivocal or suspicious recurrence/metastasis on conventional imaging, elevated tumor markers, or clinical symptoms during follow-up.

ACR Appropriateness Criteria® Post-Treatment Surveillance of Bladder Cancer: 2021 Update

Urothelial cancer is the second most common cancer, and cause of cancer death, related to the genitourinary tract. The goals of surveillance imaging after the treatment of urothelial cancer of the urinary bladder are to detect new or previously undetected urothelial tumors, to identify metastatic disease, and to evaluate for complications of therapy. For surveillance, patients can be stratified into one of three groups: 1) nonmuscle invasive bladder cancer with no symptoms or additional risk factors; 2) nonmuscle invasive bladder cancer with symptoms or additional risk factors; and 3) muscle invasive bladder cancer. This document is a review of the current literature for urothelial cancer and resulting recommendations for surveillance imaging. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

ACR Appropriateness Criteria® Post-Treatment Surveillance of Bladder Cancer

Urothelial cancer is the second most common cancer, and cause of cancer death, related to the genitourinary tract. The goals of surveillance imaging after the treatment of urothelial cancer of the urinary bladder are to detect new or previously undetected urothelial tumors, to identify metastatic disease, and to evaluate for complications of therapy. For surveillance, patients can be stratified into one of three groups: (1) nonmuscle invasive bladder cancer with no symptoms or additional risk factors; (2) nonmuscle invasive bladder cancer with symptoms or additional risk factors; and (3) muscle invasive bladder cancer. This article is a review of the current literature for urothelial cancer and resulting recommendations for surveillance imaging. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

The Future of Nuclear Medicine as an Independent Specialty

In this article, we provide an overview of established and emerging conventional nuclear medicine and PET imaging biomarkers, as the diagnostic nuclear medicine portfolio is rapidly expanding. Next, we review briefly nuclear theranostic approaches that have already entered or are about to enter clinical routine. Using some approximations and taking into account emerging applications, we also provide some simplified business forecasts for nuclear theranostics. We argue that an optimistic outlook by the nuclear medicine community is crucial to the growth of the specialty and emphasize the urgent need for training adaptations.

Using Big Data in oncology to prospectively impact clinical patient care: A proof of concept study

OBJECTIVE

Big Data is widely seen as a major opportunity for progress in the practice of personalized medicine, attracting the attention from medical societies and presidential teams alike as it offers a unique opportunity to enlarge the base of evidence, especially for older patients underrepresented in clinical trials. This study prospectively assessed the real-time availability of clinical cases in the Health & Research Informatics Total Cancer Care™ (TCC) database matching community patients with cancer, and the impact of such a consultation on treatment.

MATERIALS AND METHODS

Patients aged 70 and older seen at the Lynn Cancer Institute (LCI) with a documented malignancy were eligible. Geriatric screening information and the oncologist's pre-consultation treatment plan were sent to Moffitt. A search for similar patients was done in TCC and additional information retrieved from Electronic Medical Records. A report summarizing the data was sent and the utility of such a consultation was assessed per email after the treatment decision.

RESULTS

Thirty one patients were included. The geriatric screening was positive in 87.1% (27) of them. The oncogeriatric consultation took on average 2.2 working days. It influenced treatment in 38.7% (12), and modified it in 19.4% (6). The consultation was perceived as "somewhat" to "very useful" in 83.9% (26).

CONCLUSION

This study establishes a proof of concept of the feasibility of real time use of Big Data for clinical practice. The geriatric screening and the consultation report influenced treatment in 38.7% of cases and modified it in 19.4%, which compares very well with oncogeriatric literature. Additional steps are needed to render it financially and clinically viable.

PET-PANC: multicentre prospective diagnostic accuracy and health economic analysis study of the impact of combined modality 18fluorine-2-fluoro-2-deoxy-d-glucose positron emission tomography with computed tomography scanning in the diagnosis and management of pancreatic cancer

BACKGROUND

Pancreatic cancer diagnosis and staging can be difficult in 10-20% of patients. Positron emission tomography (PET)/computed tomography (CT) adds precise anatomical localisation to functional data. The use of PET/CT may add further value to the diagnosis and staging of pancreatic cancer.

OBJECTIVE

To determine the incremental diagnostic accuracy and impact of PET/CT in addition to standard diagnostic work-up in patients with suspected pancreatic cancer.

DESIGN

A multicentre prospective diagnostic accuracy and clinical value study of PET/CT in suspected pancreatic malignancy.

PARTICIPANTS

Patients with suspected pancreatic malignancy.

INTERVENTIONS

All patients to undergo PET/CT following standard diagnostic work-up.

MAIN OUTCOME MEASURES

The primary outcome was the incremental diagnostic value of PET/CT in addition to standard diagnostic work-up with multidetector computed tomography (MDCT). Secondary outcomes were (1) changes in patients' diagnosis, staging and management as a result of PET/CT; (2) changes in the costs and effectiveness of patient management as a result of PET/CT; (3) the incremental diagnostic value of PET/CT in chronic pancreatitis; (4) the identification of groups of patients who would benefit most from PET/CT; and (5) the incremental diagnostic value of PET/CT in other pancreatic tumours.

RESULTS

Between 2011 and 2013, 589 patients with suspected pancreatic cancer underwent MDCT and PET/CT, with 550 patients having complete data and in-range PET/CT. Sensitivity and specificity for the diagnosis of pancreatic cancer were 88.5% and 70.6%, respectively, for MDCT and 92.7% and 75.8%, respectively, for PET/CT. The maximum standardised uptake value (SUVmax.) for a pancreatic cancer diagnosis was 7.5. PET/CT demonstrated a significant improvement in relative sensitivity (p = 0.01) and specificity (p = 0.023) compared with MDCT. Incremental likelihood ratios demonstrated that PET/CT significantly improved diagnostic accuracy in all scenarios (p < 0.0002). PET/CT correctly changed the staging of pancreatic cancer in 56 patients (p = 0.001). PET/CT influenced management in 250 (45%) patients. PET/CT stopped resection in 58 (20%) patients who were due to have surgery. The benefit of PET/CT was limited in patients with chronic pancreatitis or other pancreatic tumours. PET/CT was associated with a gain in quality-adjusted life-years of 0.0157 (95% confidence interval -0.0101 to 0.0430). In the base-case model PET/CT was seen to dominate MDCT alone and is thus highly likely to be cost-effective for the UK NHS. PET/CT was seen to be most cost-effective for the subgroup of patients with suspected pancreatic cancer who were thought to be resectable.

CONCLUSION

PET/CT provided a significant incremental diagnostic benefit in the diagnosis of pancreatic cancer and significantly influenced the staging and management of patients. PET/CT had limited utility in chronic pancreatitis and other pancreatic tumours. PET/CT is likely to be cost-effective at current reimbursement rates for PET/CT to the UK NHS. This was not a randomised controlled trial and therefore we do not have any information from patients who would have undergone MDCT only for comparison. In addition, there were issues in estimating costs for PET/CT. Future work should evaluate the role of PET/CT in intraductal papillary mucinous neoplasm and prognosis and response to therapy in patients with pancreatic cancer.

STUDY REGISTRATION

Current Controlled Trials ISRCTN73852054 and UKCRN 8166.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Concurrent Diffuse Pyelonephritis and Prostatitis: Discordant Findings on Sequential FDG PET/CT and 67Ga SPECT/CT Imaging

A 45-year-old man underwent FDG PET/CT for initial imaging evaluation of recurrent Escherichia coli urinary tract infections, which demonstrated no significant FDG uptake in either kidney and subtle FDG uptake in the right prostate lobe. Subsequent Ga SPECT/CT demonstrated abnormal intense gallium uptake throughout the right kidney and entire prostate gland, clearly discordant with PET/CT findings and consistent with unexpected concurrent pyelonephritis and prostatitis. Although FDG has effectively replaced Ga in everyday clinical practice, the current case serves as a reminder that there is still a role for Ga in the evaluation of genitourinary infections.

Impact on Patient Management of [18F]-Fluorodeoxyglucose-Positron Emission Tomography (PET) Used for Cancer Diagnosis: Analysis of Data From the National Oncologic PET Registry

INTRODUCTION

We assessed the impact of [(18)F]-fluorodeoxyglucose (FDG)-positron emission tomography (PET) on intended management of patients in the National Oncologic PET Registry (NOPR) for three different diagnostic indications: (a) determining whether a suspicious lesion is cancer (Dx), (b) detecting an unknown primary tumor site when there is confirmed or strongly suspected metastatic disease (cancer of unknown primary origin [CUP]), and (c) detecting a primary tumor site when there is a presumed paraneoplastic syndrome (PNS).

METHODS

We reviewed a sample of randomly selected reports of NOPR subjects who underwent PET for Dx and CUP and all reports for PNS to find subjects for analysis. For these studies, we evaluated the impact of PET on referring physicians' intended management, based on their management plans reported before and after PET.

RESULTS

Intended management was changed more frequently in the CUP group (43.1%) than in the Dx (23.9%) and PNS (25.4%) groups (CUP vs. Dx, p < .0001; PNS vs. Dx, p < .0001; CUP vs. PNS, p < .0002). Referring physicians reported that, in light of PET results, they were able to avoid further testing in approximately three-fourths of patients (71.8%-74.6%). At the time when the post-PET forms were completed, biopsies of suspicious sites had been performed in 21.2%, 32.4%, and 23.2%, respectively, of Dx, CUP, and PNS cases.

CONCLUSION

Our analysis of NOPR data shows that PET appears to have a substantial impact on intended management when used for three common diagnostic indications.

IMPLICATIONS FOR PRACTICE

[(18)F]-fluorodeoxyglucose-positron emission tomography appears to have a substantial impact on intended management when used for three targeted diagnostic indications: (a) determining whether a suspicious lesion is cancer, (b) detecting an unknown primary tumor site in a patient with confirmed or strongly suspected metastatic disease, and (c) detecting a primary tumor site in a patient with a presumed paraneoplastic syndrome.

Acquisition with (11)C-choline and (18)F-fluorocholine PET/CT for patients with biochemical recurrence of prostate cancer: a systematic review and meta-analysis

The objective of the systematic review and meta-analysis was to evaluate whether the choice between two radiotracers, (11)C-choline ((11)C-cho) and (18)F-fluorocholine ((18)F-FCH) for PET/CT, and different acquisition protocols contributed to detect metastases for patients with biochemical recurrence of prostate cancer after radical prostatectomy or radiotherapy. We searched in January 2016 in Pubmed and Embase for articles that had used radiolabeled choline PET/CT in restaging. The meta-analysis evaluated technical and clinical aspects. Across 18 articles 1 219 of 2 213 patients (54.9 %) had a positive radiolabeled PET/CT image. Mean of the mean/median restaging PSA levels was 3.6 ± 2.7 ng/mL (range 0.5-10.7 ng/mL). Six articles with (11)C-cho PET/CT had a radiation activity of 561 ± 122 MBq and it was 293 ± 47 MBq in 12 articles with (18)F-FCH PET/CT. The difference was significant (P = 0.007, t test). Uptake time was 5 min in articles with (11)C-cho PET/CT and it was 29 ± 24 min in articles with (18)F-FCH PET/CT. The difference was significant (P = 0.02, t test). Thereby the detection rates of metastatic sites in articles with (11)C-cho (30 ± 5 %) and (18)F-FCH (39 ± 5 %) did not differ significantly (P = 0.26, t test). In linear regression analyses of the articles, the radiation activity of (11)C-cho and (18)F-FCH was not significantly associated with the detection rate of metastatic sites (P = 0.75 and P = 0.60). Restaging with radiolabeled choline PET/CT detected metastatic sites for patients with biochemical recurrence and PSA levels of 1-10 ng/mL at clinically relevant level. The choice between the two choline radiotracers and different acquisition protocols had no significant impact on detection.

Combined PET/MR: The Real Work Has Just Started. Summary Report of the Third International Workshop on PET/MR Imaging; February 17-21, 2014, Tübingen, Germany

This paper summarises the proceedings and discussions at the third annual workshop held in Tübingen, Germany, dedicated to the advancement of the technical, scientific and clinical applications of combined PET/MRI systems in humans. Two days of basic scientific and technical instructions with "hands-on" tutorials were followed by 3 days of invited presentations from active researchers in this and associated fields augmented by round-table discussions and dialogue boards with specific themes. These included the use of PET/MRI in paediatric oncology and in adult neurology, oncology and cardiology, the development of multi-parametric analyses, and efforts to standardise PET/MRI examinations to allow pooling of data for evaluating the technology. A poll taken on the final day demonstrated that over 50 % of those present felt that while PET/MRI technology underwent an inevitable slump after its much-anticipated initial launch, it was now entering a period of slow, progressive development, with new key applications emerging. In particular, researchers are focusing on exploiting the complementary nature of the physiological (PET) and biochemical (MRI/MRS) data within the morphological framework (MRI) that these devices can provide. Much of the discussion was summed up on the final day when one speaker commented on the state of PET/MRI: "the real work has just started".

Future of thoracic PET scanning

The advances in PET scanning for thoracic diseases that are deemed most likely to have clinical impact in the near-term future are highlighted in this article. We predict that the current practice of medicine will continue to embrace the power of molecular imaging and specifically PET scanning. 18F-fluorodeoxyglucose-PET scanning will continue to evolve and will expand into imaging of inflammatory disorders. New clinically available PET scan radiotracers, such as PET scan versions of octreotide and amyloid imaging agents, will expand PET imaging into different disease processes. Major improvements in thoracic PET/CT imaging technology will become available, including fully digital silicone photomultipliers and Bayesian penalized likelihood image reconstruction. These will result in significant improvements in image quality, improving the evaluation of smaller lung nodules and metastases and allowing better prediction of prognosis. The birth of clinical PET/MRI scan will add new imaging opportunities, such as better PET imaging of pleural diseases currently obscured by complex patient motion.

PET/CT imaging in cancer: current applications and future directions

Positron emission tomography (PET) is a radiotracer imaging method that yields quantitative images of regional in vivo biology and biochemistry. PET, now used in conjunction with computed tomography (CT) in PET/CT devices, has had its greatest impact to date on cancer and is now an important part of oncologic clinical practice and translational cancer research. In this review of current applications and future directions for PET/CT in cancer, the authors first highlight the basic principles of PET followed by a discussion of the biochemistry and current clinical applications of the most commonly used PET imaging agent, (18) F-fluorodeoxyglucose (FDG). Then, emerging methods for PET imaging of other biologic processes relevant to cancer are reviewed, including cellular proliferation, tumor hypoxia, apoptosis, amino acid and cell membrane metabolism, and imaging of tumor receptors and other tumor-specific gene products. The focus of the review is on methods in current clinical practice as well as those that have been translated to patients and are currently in clinical trials.

Impact of (18)F-Fluoride PET on Intended Management of Patients with Cancers Other Than Prostate Cancer: Results from the National Oncologic PET Registry

The National Oncologic PET Registry prospectively assessed the impact of PET with (18)F-sodium fluoride (NaF PET) on intended management of Medicare patients with suspected or known osseous metastasis. We report our findings for cancers other than prostate and make selected comparisons to our previously reported prostate cancer cohort.

METHODS

Data were collected from both referring and interpreting physicians before and after NaF PET in patients (age ≥ 65 y) stratified for initial staging (IS; n = 570), for suspected first osseous metastasis (FOM; n = 1,814; breast, 781 [43%]; lung, 380 [21%]; and all other cancers, 653 [36%]), and for suspected progression of osseous metastasis (POM; n = 435).

RESULTS

The dominant indication was bone pain. If NaF PET were unavailable, conventional bone scintigraphy would have been ordered in 85% of patients. In IS, 28% of patients had suspected or confirmed nonosseous metastasis. If neither conventional bone scintigraphy nor NaF PET were available, referring physicians would have ordered other advanced imaging more than 70% of the time rather than initiate treatment for suspected FOM (11%-16%) or POM (18%-22%). When intended management was classified as either treatment or nontreatment, the intended management change for each cancer type was highest in POM, lower in IS, and lowest in FOM. For suspected FOM, intended management change was lower in breast (24%), lung (36%), or other cancers (31%), compared with prostate cancer (44%) (P < 0.0001), but the NaF PET finding (normal/benign/equivocal, probable, or definite metastases) frequencies were similar across cancer types. After normal/benign/equivocal PET results, 15% of breast, 30% lung, and 38% prostate cancer patients had treatment, likely reflecting differences in management of nonosseous disease. For patients with definite metastasis on NaF PET, nonprostate, compared with prostate, cancer patients had post-PET plans for more frequent biopsy, alternative imaging, chemotherapy, and radiotherapy. In the smaller IS and POM cohorts, differences among cancer types were not significant.

CONCLUSION

Overall, NaF PET led to change in intended management in a substantial fraction of nonprostate cancer patients. In the setting of suspected FOM, NaF PET had a lower immediate impact on the treat/nontreat decision in nonprostate versus prostate cancer patients, which is consistent with current practice guidelines.

Follow-up or Surveillance (18)F-FDG PET/CT and Survival Outcome in Lung Cancer Patients

The value of performing follow-up PET/CT imaging more than 6 mo after the conclusion of therapy-either as a routine practice or because of clinically suspected recurrence-is not well established. The purpose of this study was to evaluate the added value of follow-up PET/CT to the clinical assessment and survival outcome of lung cancer patients.

METHODS

This was a retrospective study of 261 biopsy-proven lung cancer patients at a single tertiary center. In total, 488 follow-up PET/CT scans done 6 or more months after the completion of initial treatment were included in this study. Median follow-up from the completion of primary treatment was 29.3 mo (range, 6.1-295.1 mo). Overall survival (OS) benefit was measured using Kaplan-Meier plots with a Mantel-Cox log-rank test. A multivariate Cox regression model was provided with clinical covariates.

RESULTS

Of the 488 PET/CT scans, 281 were positive and 207 negative for recurrence. Overall median survival from the time of the PET/CT study was 48.5 mo. The median survival of PET-positive and PET-negative groups was 32.9 and 81.6 mo, respectively (P < 0.0001). A subgroup analysis demonstrated a similar difference in OS for 212 scans completed between 6 and 24 mo after treatment (P = 0.0004) and 276 scans completed after 24 mo (P = 0.0006). In the context of clinical assessment, PET/CT identified recurrence in 43.7% (107/245) of scans without prior clinical suspicion and ruled out recurrence in 15.2% (37/243) of scans with prior clinical suspicion. There was a significant difference in OS when grouped by clinical suspicion (P = 0.0112) or routine follow-up (P < 0.0001). In a multivariate Cox regression model, factors associated with OS were age (P < 0.0001) and PET/CT result (P = 0.0003). An age-stratified subgroup analysis demonstrated a significant difference in OS by PET scan result among patients younger than 60 y and between 60 and 70 y but not in those older than 70 y (P < 0.0001, P = 0.0004, and P = 0.8193, respectively).

CONCLUSION

(18)F-FDG PET/CT performed for follow-up more than 6 mo after the completion of primary treatment adds value to clinical judgment and is a prognostic marker of OS in lung cancer patients, regardless of the timing of the follow-up scan, and especially in patients younger than 70 y.

Impact of 18F-fluoride PET in patients with known prostate cancer: initial results from the National Oncologic PET Registry

Under Medicare's Coverage with Evidence Development policy, PET using (18)F-sodium fluoride (NaF PET) to identify osseous metastasis became a covered service if prospective registry data were collected. The National Oncologic PET Registry (NOPR) developed a NaF PET registry built on the foundation of its prior registry for PET with (18)F-FDG. Men with prostate cancer represented 72% of the cases.

METHODS

Prospective data before and after NaF PET were collected from referring and interpreting physicians. The analysis set consisted of consenting men age 65 y or older with prostate cancer undergoing NaF PET for initial staging (IS, n = 1,024), suspected first osseous metastasis (FOM, n = 1,997), or suspected progression of osseous metastasis (POM, n = 510).

RESULTS

Referring physicians indicated that if NaF PET were not available, other advanced imaging (body CT, MR imaging, or (18)F-FDG PET) would be their plan in about half of the cases. After NaF PET, the postimaging plan was revised to treatment in 77%, 52%, and 71% for IS, FOM, and POM, respectively. When intended management was classified as either treatment or nontreatment, the overall change in intended management ranged from 44% to 52% and from 12% to 16% if no effect was assumed for those cases with pre-PET plans for other imaging (imaging-adjusted impact). Interpreting physicians recorded definite findings of bone metastasis in 14%, 29%, and 76% for IS, FOM, and POM, respectively. The intended care patterns varied widely across indication and scan abnormality category combinations.

CONCLUSION

NaF PET has high overall impact, principally related to its effect on replacing intended use of other advanced imaging. Its imaging-adjusted impact was similar to that observed with (18)F-FDG PET for restaging or suspected recurrence in other cancer types.

Intended versus inferred care after PET performed for initial staging in the National Oncologic PET Registry

The National Oncologic PET Registry (NOPR) collected data on intended management before and after PET in cancer patients. We have previously reported that PET was associated with a change in intended management of about one third of patients and was consistent across cancer types. It is uncertain if intended management plans reflect the actual care these patients received. One approach to assess actual care received is using administrative claims to categorize the type and timing of clinical services.

METHODS

NOPR data from 2006 to 2008 were linked to Medicare claims for consenting patients aged 65 y or older undergoing initial-staging PET scanning for bladder, ovarian, pancreatic, small cell lung, or stomach cancers. We determined the 60-d agreement between claims-inferred care and NOPR treatment plans.

RESULTS

Patients (n = 4,661) were assessed, and 30%-52% had metastatic disease. Planned treatments were about two-thirds monotherapy, of which 46% was systemic therapy only, and one-third combinations. Claims paid by 60 d confirmed the NOPR plan of any systemic therapy, radiotherapy, or surgery in 79.3%, 64.7%, and 63.6%, respectively. Single-mode plans were much more often confirmed: systemic therapy in more than 85% of patients with ovarian, pancreatic, and small cell lung cancers and surgery in more than 73% of those with bladder, pancreatic, and stomach cancers. Intended combination treatments had claims for both in only 28% of patients receiving surgery-based combinations and in 55% receiving chemoradiotherapy. About 90% of patients with NOPR-planned systemic therapy had evaluation or management claims from a medical oncologist. An age of less than 75 y was associated more often with confirmation of chemotherapy, less often for radiotherapy but not with confirmation of surgery. Performance status or comorbidity did not explain confirmation rates within action categories, but confirmation rates were higher if the referrer specialized in the planned treatment.

CONCLUSION

Claims confirmations of NOPR intent for initial staging were widely variable but were higher than previously reported for restaging PET, suggesting that measuring change in intended management is a reasonable method for assessing the impact diagnostic tests have on actual care.