Positron emission tomography in the diagnosis and staging of lung cancer: a systematic, quantitative review

Epithelial granuloma occurring on the staple-stump after segmentectomy for ovarian cancer lung metastasis

When a mass occurs at the staple line following lung resection, it can be difficult to distinguish between local cancer recurrence and granuloma. We present a case of a staple-line granuloma with 18F-fluorodeoxyglucose-positron emission tomography uptake and elevated serum carbohydrate antigen 19-9 (CA19-9) in a patient with ovarian cancer lung metastasis. After granuloma resection, serum CA19-9 levels normalized, and CA19-9 positive cells were identified in the resected tumor. Therefore, serum CA19-9 elevation does not rule out a staple-line granuloma. Whereas granulomas on computed tomography (CT) scans tend to show smooth shadows along the staple line unilaterally, detailed CT evaluation may help diagnostic differentiation. Differentiation based on imaging and tumor markers has limitations. However, core needle biopsy has the risk of misdiagnosis and tumor cell dissemination, therefore surgical resection should be considered when comprehensive findings indicate a potential recurrence.

Imaging biomarkers for evaluating tumor response: RECIST and beyond

Response Evaluation Criteria in Solid Tumors (RECIST) is the gold standard for assessment of treatment response in solid tumors. Morphologic change of tumor size evaluated by RECIST is often correlated with survival length and has been considered as a surrogate endpoint of therapeutic efficacy. However, the detection of morphologic change alone may not be sufficient for assessing response to new anti-cancer medication in all solid tumors. During the past fifteen years, several molecular-targeted therapies and immunotherapies have emerged in cancer treatment which work by disrupting signaling pathways and inhibited cell growth. Tumor necrosis or lack of tumor progression is associated with a good therapeutic response even in the absence of tumor shrinkage. Therefore, the use of unmodified RECIST criteria to estimate morphological changes of tumor alone may not be sufficient to estimate tumor response for these new anti-cancer drugs. Several studies have reported the low reliability of RECIST in evaluating treatment response in different tumors such as hepatocellular carcinoma, lung cancer, prostate cancer, brain glioma, bone metastasis, and lymphoma. There is an increased need for new medical imaging biomarkers, considering the changes in tumor viability, metabolic activity, and attenuation, which are related to early tumor response. Promising imaging techniques, beyond RECIST, include dynamic contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI), diffusion-weight imaging (DWI), magnetic resonance spectroscopy (MRS), and ¹⁸ F-fluorodeoxyglucose (FDG) positron emission tomography (PET). This review outlines the current RECIST with their limitations and the new emerging concepts of imaging biomarkers in oncology.

Does Tumor FDG-PET Avidity Represent Enhanced Glycolytic Metabolism in Non-Small Cell Lung Cancer?

BACKGROUND

In non-small cell lung cancer (NSCLC), 18fluoro-2-deoxyglucose-positron emission tomography (FDG-PET) assists in diagnosis, staging, and evaluating treatment response. One variable of FDG-PET, the maximum standard uptake value (SUVm), is considered an objective measure of glucose uptake. However, little is known about the fate of glucose in FDG-avid lung tumors in vivo. This study used stable glucose isotope tracing to determine whether the SUVm predicts glycolytic metabolism or other glucose fates in tumors.

METHODS

In this prospective Institutional Review Board-approved clinical trial, 52 untreated potentially resectable confirmed NSCLC patients underwent FDG-PET computed tomography. During the surgical procedure, the patients were infused with 13C-labeled glucose. Blood, tumor, and normal lung samples were analyzed by mass spectrometry to determine 13C enrichment in glycolytic intermediates. These values were compared with clinical variables, including SUVm, maximum tumor diameter, stage, grade, and MIB-1/Ki67 proliferation index.

RESULTS

For each patient, 13C enrichment in each metabolite was compared between tumor and adjacent lung. Although all tumors metabolized glucose, SUVm did not correlate with glycolytic intermediate labeling. Rather, SUVm correlated with markers indicating the use of other respiratory substrates, including lactate, and with the proliferation index.

CONCLUSIONS

SUVm does not correlate with glycolytic metabolism in human NSCLC but does correlate with the proliferation index, suggesting that SUVm predicts glucose use by pathways other than glycolysis. These pathways may offer alternative therapeutic targets, including biosynthetic pathways required for cell proliferation. The research techniques in this study offer the opportunity to understand the relationships between SUVm, tumor metabolism, and therapeutic vulnerabilities in human NSCLCs.

The synthesis of rare earth metal-doped upconversion nanoparticles coated with d-glucose or 2-deoxy-d-glucose and their evaluation for diagnosis and therapy in cancer

Silica coated NaY_0.8Yb_0.16Tm_0.04F₄ NPs functionalized with d-glucose or 2-deoxy-d-glucose were prepared. Cytotoxicity and uptake studies on MCF-7 cells revealed the potential of formulation in bioimaging, therapy.

Quantitative volumetric metabolic measurement of solitary pulmonary nodules by F-18 fluorodeoxyglucose positron emission tomography-computed tomography

Background

This study aims to evaluate the effect of quantitative volumetric metabolic measurements in F-18 fluorodeoxyglucose positron emission tomographycomputed tomography to distinguish benign and malignant solitary pulmonary nodules.

Methods

We retrospectively reviewed 78 patients (56 males; 22 females; mean age 61±11.9 years; range, 32 to 82 years) with solitary pulmonary nodules who underwent F-18 fluorodeoxyglucose positron emission tomography-computed tomography. Patients were classified as benign, malignant and metastatic lesions according to pathology results. Metabolic volume, maximum standardized uptake value, mean standardized uptake value, maximum metabolic index and mean metabolic index were measured. Mean, median and standard error values were calculated for each group. Nonparametric tests were used for the comparison of each group. Partial correlation analysis was used for the relationship between parameters. For all parameters, cut-off values were obtained with receiver operating characteristic analysis.

Results

Of 78 lesions, 10 were benign (12.8%), 38 were primary lung carcinoma (48.7%) and 30 were metastatic lung nodules (38.5%). There was a significant difference between benign lesions and primary lung cancer and between primary lung cancer and metastatic groups in all parameters (p<0.05). We determined highly significant positive correlation between maximum standardized uptake value and maximum metabolic index (r=0.73; p<0.05), and moderate positive correlation between mean standardized uptake value and mean metabolic index (r=0.56; p<0.05). In receiver operating characteristic analysis, maximum standardized uptake value and mean standardized uptake value were found to be the most sensitive and specific methods for benign/malignant discrimination. In the cut-off value=2.59, the sensitivity and specificity for maximum standardized uptake value were 98.0% and 91.7%, respectively. In the cut-off value=1.65, the sensitivity and specificity for mean standardized uptake value were 94.0% and 91.7%, respectively.

Conclusion

Maximum metabolic index value is highly correlated with maximum standardized uptake value in benign/malignant solitary pulmonary nodules discrimination by F-18 fluorodeoxyglucose positron emission tomographycomputed tomography. Maximum metabolic index can also be used for discrimination of primary/metastatic malignant lesions.

Gated 18F-FDG PET/CT of the Lung Using a Respiratory Spirometric Gating Device: A Feasibility Study

Spirometric gating devices (SGDs) can measure the respiratory signal with high temporal resolution and accuracy. The primary objective of this study was to assess the feasibility and tolerance of a gated lung PET/CT acquisition using an SGD. The secondary objective was to compare the technical quality, accuracy, and interoperability of the SGD with that of a standard respiratory gating device, Real-Time Position Management (RPM), based on measurement of vertical thoracoabdominal displacement. Methods: A prospective phase I monocentric clinical study was performed on patients undergoing ¹⁸F-FDG PET/CT for assessment of a solitary lung nodule, staging of lung malignancy, or planning of radiotherapy. After whole-body PET/CT, a centered gated acquisition of both PET and CT was simultaneously obtained with the SGD and RPM during normal breathing. Results: Of the 46 patients who were included, 6 were prematurely excluded (1 because of hyperglycemia and 5 because of distant metastases revealed by whole-body PET/CT, leading to an unjustified extra gated acquisition). No serious adverse events were observed. Of the 40 remaining patients, the gated acquisition was prematurely stopped in 1 patient because of mask discomfort (2.5%; confidence interval [CI], 0.1%-13.2%). This event was considered patient tolerance failure. The SGD generated accurately gated PET/CT images, with more than 95% of the breathing cycle detected and high temporal resolution, in 34 of the 39 patients (87.2%; 95% CI, 60.0%-100.0%) and failed to generate a biologic tumor volume in 1 of 21 patients with increased ¹⁸F-FDG uptake (4.8%; 95% CI, 0.1%-26.5%). The quality and accuracy of respiratory signal detection and synchronization were significantly better than those obtained with RPM (P < 0.05). Conclusion: This trial supports the use of an SGD for gated lung PET/CT because of its high patient tolerance and accuracy. Although this technique seems to technically outperform RPM for gated PET/CT, further assessment of its superiority and the clinical benefit is warranted. We believe that this technique could be used as a gold standard to develop innovative approaches to eliminate respiration-induced blurring artifacts.

An assessment of 18 F-FDG PET/CT for thoracic screening and risk stratification of pulmonary nodules in multiple endocrine neoplasia type 1

CONTEXT

Bronchopulmonary neuroendocrine tumours (bpNETs) and thymic carcinoid (ThC) are features of multiple endocrine neoplasia type 1 (MEN 1), and surveillance guidelines recommend periodic thoracic imaging. The optimal thoracic imaging modality and screening frequency remain uncertain as does the prognosis of small lung nodules when identified.

OBJECTIVES

To evaluate fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸ F-FDG PET/CT) for identification and prognostic assessment of thoracic lesions in MEN 1.

DESIGN

Retrospective observational study.

SETTING AND PARTICIPANTS

Fifty consecutive MEN 1 patients undergoing screening with ¹⁸ F-FDG PET/CT at a tertiary referral hospital between July 2011 and December 2016.

INTERVENTIONS

¹⁸ F-FDG PET/CT.

OUTCOME MEASURES

Pulmonary and thymic lesion prevalence, size, functional characteristics and behaviour.

RESULTS

Thirteen patients (26.0%) exhibited pulmonary nodules with multiple nodules identified in nine (18.0%). An asymptomatic 31 mm FDG-avid ThC was identified in one patient (2%). Of the 13 patients with pulmonary nodules, four (8.0%) exhibited 13 FDG-avid nodules (mean size 10.1 ± 9.1 mm), and nine (18.0%) demonstrated 26 FDG nonavid nodules (mean size 6.9 ± 5.8 mm). All FDG-avid lesions increased in size vs 11 (42.3%) FDG nonavid lesions (P = .0004). For FDG-avid and nonavid nodules, the median doubling time was 24.2 months (IQR 11.4-40.7) and 48.6 months (IQR 37.0-72.2), respectively. Nodule resection was undertaken in two patients, typical bronchial carcinoid diagnosed in one (FDG nonavid) and metastatic renal cell carcinoma in the second (FDG avid).

CONCLUSION

Thoracic imaging with ¹⁸ F-FDG PET/CT effectively identifies pulmonary nodules and ThC. FDG-avid pulmonary lesions are significantly more likely to progress than nonavid lesions.

[Role of PET/CT in primitive non-small cell bronchopulmonary cancer]

Bronchopulmonary cancer is a real public health problem. Morphological imaging plays a central role in its diagnosis, staging as well as post-therapeutic assessment but it has some limitations. Metabolic imaging is a more recent technique which allows to significantly improve the overall imagery performance. We conducted a retrospective, descriptive and analytical study at the Ibn Sina Hospital and at the Military Hospital of instruction Mohammed V in Rabat over a period of 18 months, between September 2014 and February 2016, in order to evaluate the role of Fluorodeoxyglucose-PET/CT in the staging and restaging of non-small cell bronchopulmonary cancer. Initial staging showed a vast majority of locally advanced and metastatic stages: stage IV (40%), Stage IIIB (36%), Stage IIIA (16%), Stage II (8%). PET-CT allowed to detect new sites which were not initially seen on CT scan in 24 cases: 15 new ganglion sites, 8 new adrenal sites and 6 sites of bone lesions. PET/CT allowed to modify initial tumor stage in 60% of cases: upstaging in 23 patients (46%) and downstaging in 7 patients(14%). The initial stage remained unchanged in 40% of patients. Our study confirms the data from the literature concerning the superiority of PET-CT in comparison with CT scan, but only in the optimization of the non-small cell bronchopulmonary cancer management, in particular in locoregional and distant staging.

Diagnostic value of 18F-fluordesoxyglucose positron emission tomography for patients with brain metastasis from unknown primary site

BACKGROUND

In 30% of patients with brain metastasis (BM), neurological symptoms are the first clinical manifestation of systemic malignancy, referred to as BM from cancer of unknown primary site (BM-CUPS). Here, we define the diagnostic value of ¹⁸F-fluordesoxyglucose positron emission tomography (FDG-PET/CT) in the workup of BM-CUPS.

METHODS

We screened 565 patients operated for BM at the University Hospital Zurich and identified 64 patients with BM-CUPS with data on both FDG-PET/CT and contrast-enhanced chest/abdomen computed tomography (CT) available at BM diagnosis. A cohort of 125 patients with BM-CUPS from Lille and Vienna was used for validation.

RESULTS

FDG-PET/CT was not superior to chest/abdomen CT in localising the primary lesion in the discovery cohort, presumably because most primary tumours were lung cancers. However, FDG-PET/CT identified additional lesions suspicious of extracranial metastases in 27 of 64 patients (42%). The inclusion of FDG-PET/CT findings shifted the graded prognostic assessment (GPA) score from 3 with CT alone to 2.5 for PET/CT (p = 3.8 × 10^-5, Wilcoxon's test), resulting in a predicted survival of 5.3 versus 3.8 months (p = 6.1 × 10^-5; Wilcoxon's test). All observations were confirmed in the validation cohort.

CONCLUSIONS

Lung cancers are the most common primary tumour in BM-CUPS; accordingly, CT alone shows similar overall sensitivity for detecting the primary tumour as FDG-PET/CT. Yet, FDG-PET/CT improves the accuracy of staging by detecting more metastases, reflected by decreased GPA scores and decreased predicted survival. Therefore, randomised trials on patients with BM should standardise methods of staging, notably when stratifying for GPA.

Combining Independent Studies of Diagnostic Fluorodeoxyglucose Positron-Emission Tomography and Computed Tomography in Mediastinal Lymph Node Staging for Non-Small Cell Lung Cancer

Aims and background

A meta-analysis of diagnostic test performance was conducted to compare the results of relevant studies reporting diagnostic accuracy values for mediastinal staging in patients with non-small cell lung cancer (NSCLC). This paper deals with the two most accurate imaging techniques currently in use: positron emission tomography (PET) with FDG and computed tomography (CT). A statistical pooling method was used to perform a quantitative meta-analysis aimed at demonstrating the potential advantage of one of these two methods.

Methods

Studies in all languages published between 1998 and 2005 that examined the use of FDG-PET and CT for mediastinal staging in NSCLC patients, enrolled at least 18 participants, and provided enough data to allow calculation of sensitivity and specificity rates were considered eligible for the quantitative meta-analysis. Statistical methods to pool the overall estimates of sensitivity and specificity and to compare the discriminant power of PET and CT were discussed and used.

Results

Of the 13 studies included in the analysis, 12 reported greater accuracy of FDG-PET than CT in detecting mediastinal lymph node metastases. The sensitivity of FDG-PET ranged from 50% to 100%. The estimate of the overall sensitivity was 0.83% with 95% CI (0.749–0.913). Specificity ranged from 79% to 100%, with an overall estimated specificity of 0.87% with 95% CI (0.80–0.95). For CT, the sensitivity and specificity ranged from 50% to 97% and 58% to 94%, respectively; the overall estimate was 0.68% with 95% CI (0.582–0.788) and 0.76% with 95% CI (0.668–0.859). The summary receiver operating characteristic (SROC) approach was used to assess the superior diagnostic accuracy of one of the two methods. The areas under the two SROC curves were AUCPET = 0.909 vs AUCCT = 0.794.

Conclusions

Numerical and visual results of the meta-analysis of recent relevant reports agreed that FDG-PET is more accurate than CT in identifying mediastinal lymph node metastases in non-small cell lung cancer.

18F-Fluoro-2-Deoxy-d-Glucose PET/Computed Tomography Evaluation of Lung Cancer in Populations with High Prevalence of Tuberculosis and Other Granulomatous Disease

Pulmonary tuberculosis infects one-third of world's population and is responsible for the high mortality and morbidity in developing countries. The presence of a high number of macrophages and lymphocytes in active tuberculosis granulomas is associated with high uptake of ¹⁸F-fluoro-2-deoxy-d-glucose on PET imaging mimicking lung cancer. In many cases, radiological features of pulmonary tuberculosis are undistinguishable from lung cancer, which makes the diagnosis difficult. Clinical history and computed tomographic (CT) findings on a hybrid PET/CT are as important as findings on a PET in the diagnosis of lung cancer.

Monitoring and management of lung cancer patients following curative-intent treatment: clinical utility of 2-deoxy-2-[fluorine-18]fluoro-d-glucose positron emission tomography/computed tomography

A large number of studies have demonstrated that 2-deoxy-2-[fluorine-18]fluoro-d-glucose positron emission tomography/computed tomography (FDG-PET/CT) is superior to conventional modalities for the diagnosis of lung cancer and the evaluation of the extent of the disease. However, the efficacy of PET/CT in a follow-up surveillance setting following curative-intent treatments for lung cancer has not yet been established. We reviewed previous papers and evaluated the potential efficacy of PET-CT in the setting of follow-up surveillance. The following are our findings: 1) PET/CT is considered to be superior or equivalent to conventional modalities for the detection of local recurrence. However, inflammatory changes and fibrosis after treatments in local areas often result in false-positive findings; 2) the detection of asymptomatic distant metastasis is considered to be an advantage of PET/CT in a follow-up setting. However, it should be noted that detection of brain metastasis with PET/CT has some limitation, similar to its use in pretreatment staging; 3) additional radiation exposure and higher medical cost arising from the use of PET/CT should be taken into consideration, particularly in patients who might not have cancer after curative-intent treatment and are expected to have a long lifespan. The absence of any data regarding survival benefits and/or improvements in quality of life is another critical issue. In summary, PET/CT is considered to be more accurate and sensitive than conventional modalities for the detection of asymptomatic recurrence after curative-intent treatments. These advantages could modify subsequent management in patients with suspected recurrence and might contribute to the selection of appropriate treatments for recurrence. Therefore, PET/CT may be an alternative to conventional follow-up modalities. However, several important issues remain to be solved. PET/CT in a follow-up surveillance setting is generally not recommended in clinical practice at the moment.

[Positron emission tomography and stereotactic body radiation therapy for lung cancer: From treatment planning to response evaluation]

Stereotactic body radiation therapy is the standard treatment for inoperable patients with early-stage lung cancer. Local control rates range from 80 to 90 % 2 years after treatment. The role of positron emission tomography in patient selection is well known, but its use for target definition or therapeutic response evaluation is less clear. We reviewed the literature in order to assess the current state of knowledge in this area.

Role of PET/Computed Tomography in Radiofrequency Ablation for Malignant Pulmonary Tumors

Radiofrequency ablation (RFA) is a useful tool for local control of unresectable pulmonary neoplastic lesions. However, RFA is limited to tumors smaller than 4 cm and peripheral lesions. The sensitivity and specificity of FDG-PET are higher than those of computed tomography. FDG-PET at 3 to 6 months after RFA is important for predicting recurrence. Complications associated with RFA, such as infection and abscess formation, which concentrate glucose in the ablation area, can cause false-positive findings in PET examination. Knowledge of the morphologic imaging features of these complications is important in avoiding these potential pitfalls.

Appropriateness criteria of FDG PET/CT in oncology

(18)Fluorine-2-fluoro-2-Deoxy-d-glucose ((18)F-FDG) positron emission tomography/computerized tomography (PET/CT) is a well-established functional imaging method widely used in oncology. In this article, we have incorporated the various indications for (18)FDG PET/CT in oncology based on available evidence and current guidelines. Growing body of evidence for use of (18)FDG PET/CT in select tumors is also discussed. This article attempts to give the reader an overview of the appropriateness of using (18)F-FDG PET/CT in various malignancies.

Pulmonary Mycobacterium kansasii Infection Mimicking Malignancy on the (18)F-FDG PET Scan in a Patient Receiving Etanercept: A Case Report and Literature Review

A 66-year-old male presented with chest pain, malaise, generalized weakness, and weight loss. He had been receiving etanercept injection for rheumatoid arthritis. Chest X-ray revealed a right upper lobe mass. Chest computed tomography (CT) showed a right apical mass, highly suggestive of a Pancoast tumor. The thoracic fluorine-18 fluoro-deoxy-glucose (¹⁸F-FDG) positron emission tomography (PET) scan demonstrated significantly high metabolic pulmonary lesions with the standardized uptake value (SUV) of 12.5, consistent with lung cancer. The patient underwent bronchoscopy and bronchoalveolar lavage (BAL). BAL cytology was negative for malignant cells. BAL acid fast bacilli (AFB) smears were positive, and Mycobacterium kansasii was eventually isolated. He received a 12-month course of rifampin, isoniazid, and ethambutol. Interval resolution of pulmonary lesions was noted on follow-up serial CT chest studies. There has been increasing incidence of nontuberculous mycobacterial infections reported in patients treated with the antitumor necrosis factor-alpha (anti-TNF-alpha) agents. Infectious foci have an increased glucose metabolism which potentially causes a high FDG uptake on the ¹⁸F-FDG PET scan, leading to undue anxiety and cost to the patients. This is the first reported case of pulmonary M. kansasii infection with a positive thoracic ¹⁸F-FDG PET study mimicking malignancy in a patient on etanercept.

Positron emission tomography/computerized tomography in lung cancer

Positron emission tomography (PET) using 2-(18F)-flouro-2-deoxy-D-glucose (FDG) has emerged as a useful tool in the clinical work-up of lung cancer. This review article provides an overview of applications of PET in diagnosis, staging, treatment response evaluation, radiotherapy planning, recurrence assessment and prognostication of lung cancer.

Indeterminate lung nodules in cancer patients: pretest probability of malignancy and the role of 18F-FDG PET/CT

OBJECTIVE

The purpose of this study was to determine likelihood of malignancy for indeterminate lung nodules identified on CT comparing two standardized models with (18)F-FDG PET/CT.

MATERIALS AND METHODS

Fifty-nine cancer patients with indeterminate lung nodules (solid tumors; diameter, ≥5 mm) on CT had FDG PET/CT for lesion characterization. Mayo Clinic and Veterans Affairs Cooperative Study models of likelihood of malignancy were applied to solitary pulmonary nodules. High probability of malignancy was assigned a priori for multiple nodules. Low (<5%), intermediate (5-60%), and high (>60%) pretest malignancy probabilities were analyzed separately. Patients were reclassified with PET/CT. Histopathology or 2-year imaging follow-up established diagnosis. Outcome-based reclassification differences were defined as net reclassification improvement. A null hypothesis of asymptotic test was applied.

RESULTS

Thirty-one patients had histology-proven malignancy. PET/CT was true-positive in 24 and true-negative in 25 cases. Negative predictive value was 78% and positive predictive value was 89%. On the basis of the Mayo Clinic model (n=31), 18 patients had low, 12 had intermediate, and one had high pretest likelihood; on the basis of the Veterans Affairs model (n=26), 5 patients had low, 20 had intermediate, and one had high pretest likelihood. Because of multiple lung nodules, 28 patients were classified as having high malignancy risk. PET/CT showed 32 negative and 27 positive scans. Net reclassification improvements respectively were 0.95 and 1.6 for Mayo Clinic and Veterans Affairs models (both p<0.0001). Fourteen of 31 (45.2%) and 12 of 26 (46.2%) patients with low and intermediate pretest likelihood, respectively, had positive findings on PET/CT for the Mayo Clinic and Veterans Affairs models, respectively. Of 15 patients with high pretest likelihood and negative findings on PET/CT, 13 (86.7%) did not have lung malignancy.

CONCLUSION

PET/CT improves stratification of cancer patients with indeterminate pulmonary nodules. A substantial number of patients considered at low and intermediate pretest likelihood of malignancy with histology-proven lung malignancy showed abnormal PET/CT findings.

[¹⁸F]FDG positron emission tomography within two weeks of starting erlotinib therapy can predict response in non-small cell lung cancer patients

Purpose

The aim of this prospective study was to evaluate whether [¹⁸F]FDG-PET/CT, performed within two weeks of starting erlotinib therapy can predict tumor response defined by RECIST 1.1 criteria after 8 weeks of treatment in patients with inoperable (stage IIIA to IV) non-small cell lung cancer patients.

Patients and Methods

Three [¹⁸F]FDG-PET/CT scans were acquired in 12 patients before (5±4 days) and after 9±3 days (early PET) and 60±6 days (late PET) of erlotinib therapy. Conventional evaluation, including at least chest CT (baseline versus after 8 weeks of treatment), was performed according to RECIST 1.1 criteria. Change in [¹⁸F]FDG uptake was compared with conventional response, progression-free survival (PFS), and overall survival (OS).

Results

By using ROC analysis, the Area Under the Curve for prediction of metabolic non-progressive disease (mNP) by early PET was 0.86 (95% CI, 0.62 to 1.1; P = 0.04) at a cut-off of 21.6% reduction in maximum Standardized Uptake Value (SUVmax). This correctly classified 11/12 patients (7 with true progressive disease; 4 with true non-progressive disease; 1 with false progressive disease). Non-progressive disease after 8 weeks of treatment according to RECIST 1.1 criteria was significantly more frequent in patients classified mNP (P = 0.01, Fisher's exact test). mNP patients showed prolonged PFS (HR = 0.27; 95% CI, 0.04 to 0.59; P<0.01) and OS (HR = 0.34; 95% CI, 0.06 to 0.84; P = 0.03). Late PET analysis provided concordant results.

Conclusion

Morphologic response, PFS and OS survival in non-small cell lung cancer patients can be predicted by [¹⁸F]FDG-PET/CT scan within 2 weeks after starting erlotinib therapy.

Pioneering and fundamental achievements on the development of positron emission tomography (PET) in oncology

Positron emission tomography (PET) with (18)F-fluorodeoxyglucose ((18)F-FDG), a glucose analog, is widely used throughout the world as an indispensable imaging modality for the management of cancer treatment. This article reviews the pioneering achievements of PET in oncology with a focus on the development of PET that occurred from 1980 through the early-1990s. (18)F-FDG was first applied for imaging of animal tumors in 1980 and for brain tumor imaging clinically in 1982. (18)F-FDG enabled to visualize liver metastasis as clear positive image that could not be obtained by conventional nuclear imaging. Subsequently, (18)F-FDG was used for imaging various cancers, such as lung, pancreas, colorectal and hepatoma. (11)C-L-methionine ((11)C-MET) that reflects amino acid transport of cancers has an advantage that its uptake is lower in the brain and inflammatory tissue compared to (18)F-FDG, and was first applied for imaging lung cancer and brain tumor. (18)F-FDG and (11)C-MET were proved to be sensitive tracers that can be used to objectively evaluate the effectiveness of cancer treatment. The diagnostic accuracy of PET, which is critical in clinical practice, was evaluated for the differential diagnosis of malignant and benign lung nodules using (18)F-FDG or (11)C-MET. In addition to (18)F-FDG and (11)C-MET, many radiopharmaceuticals were developed, such as (18)F-labled thymidine analogs for evaluating proliferative activity, (18)F-fluoromisonidazole for imaging of hypoxia, and (18)F-fluorodeoxygalactose for evaluating liver-specific galactose metabolism and for imaging of hepatoma that retains galactose metabolic activity. These early efforts and achievements have greatly contributed to the development and clinical application of (18)F-FDG PET in oncology.

Functional imaging in lung cancer

Lung cancer represents an increasingly frequent cancer diagnosis worldwide. An increasing awareness on smoking cessation as an important mean to reduce lung cancer incidence and mortality, an increasing number of therapy options and a steady focus on early diagnosis and adequate staging have resulted in a modestly improved survival. For early diagnosis and precise staging, imaging, especially positron emission tomography combined with CT (PET/CT), plays an important role. Other functional imaging modalities such as dynamic contrast-enhanced CT (DCE-CT) and diffusion-weighted MR imaging (DW-MRI) have demonstrated promising results within this field. The purpose of this review is to provide the reader with a brief and balanced introduction to these three functional imaging modalities and their current or potential application in the care of patients with lung cancer.

Benefits of point-spread function and time of flight for PET/CT image quality in relation to the body mass index and injected dose

The PET image quality of overweight patients and patients who receive low injected doses deteriorates because of increases in statistical noise. The purpose of this study was to investigate the benefits of the point-spread function (PSF) and time-of-flight (TOF) for PET/CT image quality in such patients.

METHODS

The PET images were reconstructed using the baseline ordered-subsets expectation-maximization algorithm (OSEM), OSEM + PSF, OSEM + TOF, and OSEM + PSF + TOF. In the phantom study, we used a National Electrical Manufacturers Association body phantom with different radioactivity concentrations and analyzed image quality using the coefficient of variance in the background (CVphantom). In the clinical study, we retrospectively studied 39 patients who underwent clinical F-FDG PET/CT. The patients were classified into groups based on body mass index and injected dose. Image quality was evaluated using the CV in the liver (CVliver).

RESULTS

In the phantom study, PSF and TOF improved the CVphantom, especially in low-activity models. Among all of the reconstructions, the best CVphantom was obtained with OSEM + PSF + TOF. In the clinical study, the CVliver of the low-dose group with OSEM + PSF + TOF was comparable to that of the high-dose group with conventional OSEM.

CONCLUSIONS

Point-spread function and TOF improved PET/CT image quality for overweight patients who received a lower injected dose. Therefore, the use of PSF and TOF is suggested to maintain the image quality of such patients without extending scanning times. It is greatly beneficial to obtain sufficient image quality for larger patients, especially in delivery institutions where the injection dose cannot be easily increased.

Variation in background intensity affects PET-based gross tumor volume delineation in non-small-cell lung cancer: the need for individualized information

PURPOSE

Efficient tumor volume delineation by the combined use of PET/CT scanning is necessary for the proper treatment of non-small cell lung cancer (NSCLC). To understand the effect of variation in background intensity on PET-based gross tumor volume (GTV) delineation, we determined the background standard uptake values (SUVs) in normal lung, aorta (blood pool), and liver tissues and determined GTVs using different methods.

METHODS

Thirty-seven previously untreated patients with pathologically confirmed NSCLC underwent PET/CT scanning with (18)F-fluorodeoxyglucose ((18)F-FDG). To obtain (18)F-FDG uptake values in normal tissues, regions of interest in the lung lobes (left upper, left lower, right upper, right middle, and right lower), aorta, and liver zones (left, intermediate, and right) were measured. The coefficient of variation (CV) of the SUV was measured for each normal structure. The CT-based GTV (GTV(CT)) was considered as the standard to which all PET-based GTVs were compared, and the correlation coefficient was analyzed to compare GTV obtained by the various delineation methods. Linear and logarithmic regression analyses were used to determine the relationship between GTV(CT) and GTV(PET).

RESULTS

Normal lung tissue showed a significantly lower SUV and less stability than tissue of the aorta or liver. For the lung, aorta, and liver, the maximum SUV (SUV(max)) was 0.82 ± 0.32, 2.35 ± 0.37, and 3.24 ± 0.50 (CV: 38.79%, 15.82%, and 15.30%) and average SUV (SUV(ave)) was 0.49 ± 0.18, 1.68 ± 0.32, and 2.34 ± 0.36 (CV: 36.38%, 18.92%, and 15.44%), respectively. The SUVs of the lung varied from lobe to lobe. The GTV delineation method using the SUV(ave) of the lung lobe in which the tumor was found as background in the source-to-background ratio (SBR) method showed the best correlation with the volume of CT-based GTV (r=0.81).

CONCLUSIONS

Our results show vast variation in the SUV among normal tissues, as well as in the different lung lobes. The tumor volume delineated using the SBR method correlated well with the CT-based tumor volume. We conclude that it is reasonable and precise to contour GTV in patients with NSCLC after taking into account the background intensity of the lung lobe in which the tumor is found.

Are discordant positron emission tomography and pathological assessments of the mediastinum in non-small cell lung cancer significant?

OBJECTIVE

Many patients with non-small cell lung cancer have positive mediastinal lymph nodes on preoperative positron emission tomography (PET) but do not have mediastinal involvement after surgery. The prognostic significance of this discordance was assessed.

METHODS

This Institutional Review Board-approved study evaluated patients treated with upfront surgery at Duke Cancer Institute (Durham, NC) for non-small cell lung cancer from 1995 to 2008. Those staged with PET with pN0-1 disease after negative invasive mediastinal assessment were included. Mediastinal lymph nodes were scored as positive or negative based on visual analysis of the preoperative PET. Clinical outcomes of the PET-positive and PET-negative cohorts were estimated using the Kaplan-Meier method and compared using a log-rank test. Prognostic factors were assessed using a multivariate analysis.

RESULTS

A total of 547 patients were assessed, of whom 105 (19%) were PET positive in the mediastinum. The median number of mediastinal lymph node stations sampled was 4 (range, 1-9). The 5-year risk of local recurrence was 26% in PET-positive versus 21% in PET-negative patients (P = .50). Patterns of local failure were similar between the 2 groups. Distant recurrence (35% vs 29%; P = .63) and overall survival (44% vs 54%; P = .52) were comparable for PET-positive and PET-negative patients. On multivariate analysis, a positive PET was not significant for local recurrence (hazard ratio [HR], 1; P = 1), distant recurrence (HR, 0.82; P = .42), or overall survival (HR, 1.08; P = .62).

CONCLUSIONS

Patients with positive mediastinal lymph nodes on preoperative PET, but negative on histologic analysis, are not at increased risk of disease recurrence. Pathologic staging remains the standard.

In vitro and in vivo characterization of 2-deoxy-2-18F-fluoro-D-mannose as a tumor-imaging agent for PET

2-Deoxy-2-(18)F-fluoro-d-mannose ((18)F-FDM) is an (18)F-labeled mannose derivative and a stereoisomer of (18)F-FDG. Our preliminary study demonstrated that (18)F-FDM accumulated in tumors to the same extent as (18)F-FDG, with less uptake in the brain and faster clearance from the blood. However, detailed studies on the uptake of (18)F-FDM in tumors have not been conducted. We undertook this study to establish a practical method of (18)F-FDM synthesis based on an (18)F-nucleophilic substitution (SN2) reaction and to advance the biologic characterization of (18)F-FDM for potential application as a tumor-imaging agent.

METHODS

We synthesized 4,6-O-benzylidene-3-O-ethoxymethyl-1-O-methyl-2-O-trifluoromethanesulfonyl-β-D-glucopyranoside as a precursor for the nucleophilic synthesis of (18)F-FDM. The precursor was radiofluorinated with (18)F-KF/Kryptofix222, followed by removal of the protecting groups with an acid. (18)F-FDM was purified by preparative high-performance liquid chromatography and then subjected to in vitro evaluation regarding phosphorylation by hexokinase as well as uptake and metabolism in AH109A tumor cells. The in vivo properties of (18)F-FDM were examined in Donryu rats bearing AH109A tumor cells by biodistribution studies and imaging with a small-animal PET system.

RESULTS

We radiosynthesized (18)F-FDM in sufficient radiochemical yields (50%-68%) with excellent purities (97.6%-98.7%). (18)F-FDM was phosphorylated rapidly by hexokinase, resulting in 98% conversion into (18)F-FDG-6-phosphate within 30 min. Tumor cells showed significant uptake of (18)F-FDM with time in vitro, and uptake was dose-dependently inhibited by D-glucose. (18)F-FDM injected into tumor-bearing rats showed greater uptake in tumors (2.17 ± 0.32 percentage injected dose per gram [%ID/g]) than in the brain (1.42 ± 0.10 %ID/g) at 60 min after injection. PET studies also revealed the tumor uptake of (18)F-FDM (quasi-standardized uptake value, 2.83 ± 0.22) to be the same as that of (18)F-FDG (2.40 ± 0.30), but the brain uptake of (18)F-FDM (1.89 ± 0.13) was ≈ 30% lower than that of (18)F-FDG (2.63 ± 0.26).

CONCLUSION

We prepared (18)F-FDM with good radiochemical yield and purity by an SN2 reaction. We demonstrated that (18)F-FDM had adequate tumor cell uptake by a metabolic trapping mechanism and can afford high-contrast tumor images with less uptake in the brain, indicating that (18)F-FDM has almost the same potential as (18)F-FDG for PET tumor imaging, with better advantages with regard to the imaging of brain tumors.

18F-FDG PET/CT features of pulmonary sclerosing hemangioma

BACKGROUND

Pulmonary sclerosing hemangioma (PSH) has been reported to show increased FDG uptake and be potential false-positives on 18F-FDG PET/CT examination. However, it is still unclear whether the previously-reported high FDG uptake is a universal characteristic of PSH, and furthermore, there have been no investigations on what kind of radiologic or histologic features may have been related with its FDG uptake values.

PURPOSE

To investigate the 18F-FDG PET/CT features of pulmonary sclerosing hemangiomas (PSHs), and to evaluate the relating factors with their FDG uptake values.

MATERIAL AND METHODS

We identified 10 PSHs in eight patients who had a pathologic diagnosis and available antecedent 18F-FDG PET/CT images. 18F-FDG PET/CT images were investigated both qualitatively and quantitatively, along with their histopathologic features. Correlation between 18F-FDG PET features and radiologic as well as histopathologic features were also evaluated.

RESULTS

Mean diameter of the 10 PSHs in our study was 16.9 mm ± 6.26 (range 5-25 mm). Four tumors showed intense uptake, and four tumors showed moderate uptake on 18F-FDG PET/CT scans. In the remaining two tumors, there were no significant FDG uptakes. The SUVmax of tumors ranged from 0.60-4.7 (median 2.30; 2.51 ± 1.42), and was significantly correlated with the tumor size (r = 0.754, P = 0.012) and three out of four tumors ≥2 cm (75%) showed intense FDG uptake and their SUVmax values were greater than 2.5. Immunohistochemical results for GLUT-1, GLUT-4, and Ki-67 and other pathologic features were not correlated with the tumors' FDG uptake.

CONCLUSION

The majority of PSHs show increased FDG uptakes, and their SUVmax values are significantly correlated with their tumor size. PSH ≥2 cm can frequently be falsely interpreted as malignancy in FDG-PET/CT. Further studies with large study population are warranted to confirm our observations.

FDG PET and PET/CT

Molecular imaging with positron emission tomography (PET) using tumour-seeking radiopharmaceuticals has gained wide acceptance in oncology with many clinical applications. The hybrid imaging modality PET/CT allows assessing molecular as well as morphologic information at the same time. Therefore, PET/CT represents an efficient tool for whole body staging and re-staging within one imaging modality. In oncology the glucose analogue (18)F-fluorodeoxyglucose (FDG) is the most widely used PET and PET/CT radiopharmaceutical in clinical routine. FDG PET and PET/CT have been used for staging and re-staging tumour patients in numerous studies. This chapter will discuss the use and the main indications of FDG PET and PET/CT in oncology with special emphasis on lung cancer, oesophageal cancer, colorectal cancer, head and neck cancer, lymphoma and breast cancer (among other tumour entities). A review of the current literature will be given with respect to primary diagnosis, staging and diagnosis of recurrent disease (local, lymph node and distant metastases). Besides its integral role in diagnosis, staging and re-staging of disease in oncology, there is increasing evidence that FDG PET and PET/CT can significantly contribute to therapy response assessment possibly influencing therapeutic management and treatment planning, to therapy tumour control and prediction of prognosis in oncologic patients, which will also be discussed in this chapter.

Optimal imaging protocols for lung cancer staging: CT, PET, MR imaging, and the role of imaging

Chest radiography, the most commonly performed imaging technique for the detection of lung disease, is limited in accurately detecting early lung cancer. The main imaging modality for the staging of lung cancer is computed tomography (CT), supplemented by positron emission tomography (PET), usually as a hybrid technique in conjunction with CT (PET/CT). Magnetic resonance (MR) imaging is a useful diagnostic tool for specific indications and has the advantage of not using ionizing radiation. This article discusses the optimal imaging protocols for lung cancer staging using CT, PET (PET/CT), and MR imaging, and the role of imaging in patient management.

Therapeutic effect of γ-secretase inhibition in KrasG12V-driven non-small cell lung carcinoma by derepression of DUSP1 and inhibition of ERK

Here, we have investigated the role of the Notch pathway in the generation and maintenance of Kras(G12V)-driven non-small cell lung carcinomas (NSCLCs). We demonstrate by genetic means that γ-secretase and RBPJ are essential for the formation of NSCLCs. Of importance, pharmacologic treatment of mice carrying autochthonous NSCLCs with a γ-secretase inhibitor (GSI) blocks cancer growth. Treated carcinomas present reduced HES1 levels and reduced phosphorylated ERK without changes in phosphorylated MEK. Mechanistically, we show that HES1 directly binds to and represses the promoter of DUSP1, encoding a dual phosphatase that is active against phospho-ERK. Accordingly, GSI treatment upregulates DUSP1 and decreases phospho-ERK. These data provide proof of the in vivo therapeutic potential of GSIs in primary NSCLCs.

Imaging-based tumor treatment response evaluation: review of conventional, new, and emerging concepts

Tumor response may be assessed readily by the use of Response Evaluation Criteria in Solid Tumor version 1.1. However, the criteria mainly depend on tumor size changes. These criteria do not reflect other morphologic (tumor necrosis, hemorrhage, and cavitation), functional, or metabolic changes that may occur with targeted chemotherapy or even with conventional chemotherapy. The state-of-the-art multidetector CT is still playing an important role, by showing high-quality, high-resolution images that are appropriate enough to measure tumor size and its changes. Additional imaging biomarker devices such as dual energy CT, positron emission tomography, MRI including diffusion-weighted MRI shall be more frequently used for tumor response evaluation, because they provide detailed anatomic, and functional or metabolic change information during tumor treatment, particularly during targeted chemotherapy. This review elucidates morphologic and functional or metabolic approaches, and new concepts in the evaluation of tumor response in the era of personalized medicine (targeted chemotherapy).

[Role of imaging techniques in the TNM classification of non-small cell bronchogenic carcinoma]

The Seventh Edition of the TNM Classification for non-small cell bronchogenic carcinomas include a series of changes in the T and M descriptor, in particular a re-classification of malignant pleural and pericardial effusions and of separated tumour nodes, new tumour size cut-off values and sub-divisions of the T1-T2 and M1 categories. We review these corrections that led to the changes in the staging system that affects stages II-III. Furthermore, we describe and illustrate the role of the different imaging techniques in tumour staging (CT, PET, PET-CT and MRI), highlighting their respective indications, advantages and disadvantages, as well their complementary function.

Impact of 18F-FDG PET scan on the prevalence of benign thoracic lesions at surgical resection

OBJECTIVE: The main utility of 18-fluorodeoxyglucose positron emission tomography (FDG-PET) lies in the staging of lung cancer. However, it can also be used to differentiate indeterminate pulmonary lesions, but its impact on the resection of benign lesions at surgery is unknown. The aim of this study was to compare the prevalence of benign lesions at thoracotomy carried out for suspected lung cancer, before and after the introduction of PET scanning in a large thoracic surgical centre. MATERIALS AND METHODS: We reviewed our prospectively recorded surgical database for all consecutive patients undergoing thoracotomy for suspected or proven lung cancer and compared the prevalence of benign lesions in 2 consecutive 2-year groups, before (group I) and after (group II) the introduction of FDG-PET scan respectively. RESULTS: Surgical resection was performed on 1233 patients during the study period. The prevalence of benign lesions at surgery in groups I and II was similar (44/626 and 41/607, both 7%), and also in group II between those who underwent FDG-PET scan and the remainder (21/301 and 20/306 respectively, both 7%). In group II, of the 21 patients with benign lesions, who underwent FDG-PET, 19 had a false positive scan (mean standardised uptake value 5.3 [range 2.6-12.7]). Of these, 13 and 4 patients respectively had non-diagnostic bronchoscopy and percutaneous transthoracic lung biopsy pre thoracotomy. There was no difference in the proportion of different benign lesions resected between group I and those with FDG-PET in group II. CONCLUSION: The introduction of FDG-PET scanning has not altered the proportion of patients undergoing thoracotomy for ultimately benign lesions, mainly due to the avidity for the isotope of some non-malignant lesions. Such false positive results need to be considered when patients with unconfirmed lung cancer are contemplated for surgical resection.

Non-small cell lung cancer: prognostic importance of positive FDG PET findings in the mediastinum for patients with N0-N1 disease at pathologic analysis

PURPOSE

To assess the prognostic implications of mediastinal positron emission tomographic (PET) findings in patients undergoing curative resection of non-small cell lung cancer (NSCLC) who have histologically negative mediastinal lymph nodes (LNs), with the hypothesis that positive findings at PET are prognostic even in patients with negative histologic findings in the LNs.

MATERIALS AND METHODS

Records of patients with a preoperative PET undergoing curative surgery, without adjuvant radiation, for pathologic T1-3N0-1 NSCLC at the University of North Carolina between 2000 and 2006 were reviewed as an institutional review board-approved HIPAA-compliant retrospective study. Ninety patients were evaluable (all histologically negative in mediastinum; 44 with both mediastinoscopy and surgery); 13 patients had positive mediastinal PET findings, and 77 had negative mediastinal PET findings. Local-regional and distant failure rates in patients with and those without mediastinal abnormalities at preoperative PET were compared by using logistic regression and log-rank tests.

RESULTS

Median follow-up was 54.3 months (range, 1-99 months). There were higher rates of local-regional (P = .001) and distant (P < .001) failure as well as death (P = .001) in patients with postive PET findings than in patients with negative findings. In multivariable analysis (adjusting for other prognostic factors), positive PET findings in the mediastinum remained prognostic for distant failure (P < .001, hazard ratio = 6.9) and were marginally prognostic for local-regional failure (P = .093, hazard ratio = 1.9).

CONCLUSION

Positive findings at preoperative PET in the mediastinum appear to have prognostic implications despite the mediastinal LNs being histologically negative. The high rate of local-regional and distant failure suggests that postoperative radiation therapy and/or chemotherapy may be particularly helpful in patients with positive mediastinal findings at preoperative PET.

Is 18F-FDG PET/CT useful for the early prediction of histopathologic response to neoadjuvant erlotinib in patients with non-small cell lung cancer?

Early prediction of treatment response is of value in avoiding the unnecessary toxicity of ineffective treatment. The objective of this study was to prospectively evaluate the role of integrated (18)F-FDG PET/CT for the early identification of response to neoadjuvant erlotinib, an epidermal growth factor receptor tyrosine kinase inhibitor.

METHODS

From October 2006 to March 2009, 23 patients with non-small cell lung cancer eligible for surgical resection were evaluated for this study. Patients received preoperative erlotinib (150 mg) once daily for 3 wk. (18)F-FDG PET/CT was performed before and at 1 wk after the administration of erlotinib. Changes in tumor (18)F-FDG uptake during treatment were measured by standardized uptake values and assessed prospectively according to the criteria of the European Organization for Research and Treatment of Cancer. Patients with a decrease in standardized uptake values of 25% or more after 1 wk were classified as "metabolic responders." The metabolic response was compared with the pathologic response, obtained by histopathologic examination of the resected specimen.

RESULTS

Following the (18)F-FDG PET/CT criteria of the European Organization for Research and Treatment of Cancer, 6 patients (26%) had a partial response within 1 wk, 16 patients (70%) had stable disease, and 1 patient (4%) had progressive disease. The median percentage of necrosis in the early metabolic responder group was 70% (interquartile range, 30%-91%), and the median percentage of necrosis in the nonresponder group was 40% (interquartile range, 20%-50%; P = 0.09). The kappa-agreement between the metabolic and pathologic responders was 0.55 (P = 0.008).

CONCLUSION

The results of this study suggest that early during the course of epidermal growth factor receptor tyrosine kinase inhibitor therapy, (18)F-FDG PET/CT can predict response to erlotinib treatment in patients with non-small cell lung cancer.

Lista de recomendações do Exame PET/CT com 18F-FDG em Oncologia: consenso entre a Sociedade Brasileira de Cancerologia e a Sociedade Brasileira de Biologia, Medicina Nuclear e Imagem Molecular

Apresentamos uma lista de recomendações sobre a utilização de 18F-FDG PET em oncologia, no diagnóstico, estadiamento e detecção de recorrência ou progressão do câncer. Foi realizada pesquisa para identificar estudos controlados e revisões sistemáticas de literatura composta por estudos retrospectivos e prospectivos. As consequências e o impacto da 18F-FDG PET no manejo de pacientes oncológicos também foram avaliados. A 18F-FDG PET deve ser utilizada como ferramenta adicional aos métodos de imagem convencionais como tomografia computadorizada e ressonância magnética. Resultados positivos que sugiram alteração no manejo clínico devem ser confirmados por exame histopatológico. A 18F-FDG PET deve ser utilizada no manejo clínico apropriado para o diagnóstico de cânceres do sistema respiratório, cabeça e pescoço, sistema digestivo, mama, melanoma, órgão genitais, tireoide, sistema nervoso central, linfoma e tumor primário oculto.

Anthracosis and large mediastinal mass in a patient with healed pulmonary tuberculosis

A Mexican woman, aged 71 years, with life-long exposure to soot from a wood cook stove in a closed environment, who was treated for tuberculosis 4-years prior, presented with prominent mediastinal lymphadenopathy with anthracosis. Mediastinal lymphadenopathy is a common presentation of diverse granulomatous, malignant and infectious conditions like tuberculosis. Anthracotic pigment is found in different conditions such as tuberculosis or domestically acquired particulate lung disease. Accurate assessment of chronology and causative factors presents a challenge. Recognizing that pneumoconiosis can mimic or coexist with other granulomatous, infectious and malignant conditions presenting as mediastinal lymphadenopathy is important. Misdiagnosis may result in under- or over-treatment of potentially curable conditions such as tuberculosis, under-treatment of a lethal condition such as melanoma, or exposure of patients to inappropriate administration of costly therapy with potential untoward effects.

Evidence-Based Approach to the Introduction of Positron Emission Tomography in Ontario, Canada

Purpose

The uptake of new health care technologies is usually driven by industry promotion, physician interest, patient demand, and institutional ability to acquire the technology. The introduction of positron emission tomography (PET) scanning in the province of Ontario, Canada, followed a different path.

Methods

The Ontario provincial government, through its Ministry of Health and Long-Term Care, commissioned a systematic review of the literature. When this found only weak evidence that PET has a positive impact on clinical outcomes, the Ministry introduced a provincial PET evaluation program to close the evidence gap.

Results

This article describes the challenges encountered establishing the PET evaluation program. These included the design and conduct of the initial clinical trials, the establishment of a PET cancer registry, standardizing how PET scans were performed and reported, and gaining acceptance by health professionals for the evaluative program.

Conclusion

The proliferation of health technologies is a key driver of increasing health care costs. The Ontario approach to the introduction of PET is a model worth consideration by health systems seeking to ensure that they receive value for money based on a strong evidentiary base when introducing new health technologies.