Cost-effectiveness of PET imaging in clinical oncology

How to objectively evaluate the impact of image-guided surgery technologies

PURPOSE

This manuscript aims to provide a better understanding of methods and techniques with which one can better quantify the impact of image-guided surgical technologies.

METHODS

A literature review was conducted with regard to economic and technical methods of medical device evaluation in various countries. Attention was focused on applications related to image-guided interventions that have enabled procedures to be performed in a minimally invasive manner, produced superior clinical outcomes, or have become standard of care.

RESULTS

The review provides examples of successful implementations and adoption of image-guided surgical techniques, mostly in the field of neurosurgery. Failures as well as newly developed technologies still undergoing cost-efficacy analysis are discussed.

CONCLUSION

The field of image-guided surgery has evolved from solely using preoperative images to utilizing highly specific tools and software to provide more information to the interventionalist in real time. While deformations in soft tissue often preclude the use of such instruments outside of neurosurgery, recent developments in optical and radioactive guidance have enabled surgeons to better account for organ motion and provide feedback to the surgeon as tissue is cut. These technologies are currently undergoing value assessments in many countries and hold promise to improve outcomes for patients, surgeons, care teams, payors, and society in general.

Neuroimaging Assessment of Pain

Pain is an unpleasant sensory and emotional experience. Understanding the neural mechanisms of acute and chronic pain and the brain changes affecting pain factors is important for finding pain treatment methods. The emergence and progress of non-invasive neuroimaging technology can help us better understand pain at the neural level. Recent developments in identifying brain-based biomarkers of pain through advances in advanced imaging can provide some foundations for predicting and detecting pain. For example, a neurologic pain signature (involving brain regions that receive nociceptive afferents) and a stimulus intensity-independent pain signature (involving brain regions that do not show increased activity in proportion to noxious stimulus intensity) were developed based on multivariate modeling to identify processes related to the pain experience. However, an accurate and comprehensive review of common neuroimaging techniques for evaluating pain is lacking. This paper reviews the mechanism, clinical application, reliability, strengths, and limitations of common neuroimaging techniques for assessing pain to promote our further understanding of pain.

18F-FDG-PET/CT analysis in hospitalized patients affected by pulmonary disease: The experience of the Nuclear Medicine Unit of "Policlinico Tor Vegata"

OBJECTIVE

The main aim of this study was to retrospectively evaluate the clinical data and outcomes of a cohort of 492 hospitalized patients who underwent fluorine-18-fluorodeoxyglucose (F-FDG)-PET/CT analysis at the nuclear medicine unit of 'Policlinico Tor Vergata' in Rome during the years 2017 and 2018 with particular emphasis for patients affected by pulmonary diseases.

METHODS

Anamnestic data (age and gender), main pathologic conditions, results of F-FDG-PET/CT examination, appropriateness of the request, and medical records of 492 consecutive hospitalized patients who underwent F-FDG-PET/CT analysis (55.38 ± 3.78 years; range 33-81 years) from January 2017 to December 2018 were obtained.

RESULTS

Considering all examinations, positive results were observed in 66.9% of cases whereas it was not possible to perform a diagnosis in 12.7% of cases (doubt results). About 20-fold increase in the percentage of doubt results was observed in F-FDG-PET/CT analysis with no appropriateness as compared to those with double appropriateness (both the request and clinical). Noteworthy, our data showed a 95% higher concordance between the positive results of the F-FDG-PET/CT examination and the histologic diagnosis. Conversely, the concordance between the analysis of the bronchoalveolar lavages and the PET analysis was very low.

CONCLUSION

Data here reported showed the high accuracy of the F-FDG-PET/CT performed in our department, mainly for pulmonary diseases, also highlighting the importance of continuously updating the selection criteria for patients who need PET examinations.

A picture is worth a thousand words: a history of diagnostic imaging for lymphoma

The journey from early drawings of Thomas Hodgkin's patients to deep learning with radiomics in lymphoma has taken nearly 200 years, and in many ways, it parallels the journey of medicine. By tracing the history of imaging in clinical lymphoma practice, we can better understand the motivations for current imaging practices. The earliest imaging modalities of the 2D era each had varied, site-dependent sensitivity, and the improved accuracy of imaging studies allowed new diagnostic and therapeutic techniques. First, we review the initial imaging technologies that were applied to understand lymphoma spread and achieve practical guidance for the earliest lymphoma treatments. Next, in the 3D era, we describe how anatomical imaging advances replaced and complemented conventional modalities. Afterward, we discuss how the PET era scans were used to understand response of tumors to treatment and risk stratification. Finally, we discuss the emergence of radiomics as a promising area of research in personalized medicine. We are now able to identify involved lymph nodes and body sites both before and after treatment to offer patients improved treatment outcomes. As imaging methods continue to improve sensitivity, we will be able to use personalized medicine approaches to give targeted and highly focused therapies at even earlier time points, and ideally, we can obtain long-term disease control and cures for lymphomas.

Ultrasound, CT, MRI, or PET-CT for staging and re-staging of adults with cutaneous melanoma

BACKGROUND

Melanoma is one of the most aggressive forms of skin cancer, with the potential to metastasise to other parts of the body via the lymphatic system and the bloodstream. Melanoma accounts for a small percentage of skin cancer cases but is responsible for the majority of skin cancer deaths. Various imaging tests can be used with the aim of detecting metastatic spread of disease following a primary diagnosis of melanoma (primary staging) or on clinical suspicion of disease recurrence (re-staging). Accurate staging is crucial to ensuring that patients are directed to the most appropriate and effective treatment at different points on the clinical pathway. Establishing the comparative accuracy of ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET)-CT imaging for detection of nodal or distant metastases, or both, is critical to understanding if, how, and where on the pathway these tests might be used.

OBJECTIVES

Primary objectivesWe estimated accuracy separately according to the point in the clinical pathway at which imaging tests were used. Our objectives were:• to determine the diagnostic accuracy of ultrasound or PET-CT for detection of nodal metastases before sentinel lymph node biopsy in adults with confirmed cutaneous invasive melanoma; and• to determine the diagnostic accuracy of ultrasound, CT, MRI, or PET-CT for whole body imaging in adults with cutaneous invasive melanoma:○ for detection of any metastasis in adults with a primary diagnosis of melanoma (i.e. primary staging at presentation); and○ for detection of any metastasis in adults undergoing staging of recurrence of melanoma (i.e. re-staging prompted by findings on routine follow-up).We undertook separate analyses according to whether accuracy data were reported per patient or per lesion.Secondary objectivesWe sought to determine the diagnostic accuracy of ultrasound, CT, MRI, or PET-CT for whole body imaging (detection of any metastasis) in mixed or not clearly described populations of adults with cutaneous invasive melanoma.For study participants undergoing primary staging or re-staging (for possible recurrence), and for mixed or unclear populations, our objectives were:• to determine the diagnostic accuracy of ultrasound, CT, MRI, or PET-CT for detection of nodal metastases;• to determine the diagnostic accuracy of ultrasound, CT, MRI, or PET-CT for detection of distant metastases; and• to determine the diagnostic accuracy of ultrasound, CT, MRI, or PET-CT for detection of distant metastases according to metastatic site.

SEARCH METHODS

We undertook a comprehensive search of the following databases from inception up to August 2016: Cochrane Central Register of Controlled Trials; MEDLINE; Embase; CINAHL; CPCI; Zetoc; Science Citation Index; US National Institutes of Health Ongoing Trials Register; NIHR Clinical Research Network Portfolio Database; and the World Health Organization International Clinical Trials Registry Platform. We studied reference lists as well as published systematic review articles.

SELECTION CRITERIA

We included studies of any design that evaluated ultrasound (with or without the use of fine needle aspiration cytology (FNAC)), CT, MRI, or PET-CT for staging of cutaneous melanoma in adults, compared with a reference standard of histological confirmation or imaging with clinical follow-up of at least three months' duration. We excluded studies reporting multiple applications of the same test in more than 10% of study participants.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted all data using a standardised data extraction and quality assessment form (based on the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2)). We estimated accuracy using the bivariate hierarchical method to produce summary sensitivities and specificities with 95% confidence and prediction regions. We undertook analysis of studies allowing direct and indirect comparison between tests. We examined heterogeneity between studies by visually inspecting the forest plots of sensitivity and specificity and summary receiver operating characteristic (ROC) plots. Numbers of identified studies were insufficient to allow formal investigation of potential sources of heterogeneity.

MAIN RESULTS

We included a total of 39 publications reporting on 5204 study participants; 34 studies reporting data per patient included 4980 study participants with 1265 cases of metastatic disease, and seven studies reporting data per lesion included 417 study participants with 1846 potentially metastatic lesions, 1061 of which were confirmed metastases. The risk of bias was low or unclear for all domains apart from participant flow. Concerns regarding applicability of the evidence were high or unclear for almost all domains. Participant selection from mixed or not clearly defined populations and poorly described application and interpretation of index tests were particularly problematic.The accuracy of imaging for detection of regional nodal metastases before sentinel lymph node biopsy (SLNB) was evaluated in 18 studies. In 11 studies (2614 participants; 542 cases), the summary sensitivity of ultrasound alone was 35.4% (95% confidence interval (CI) 17.0% to 59.4%) and specificity was 93.9% (95% CI 86.1% to 97.5%). Combining pre-SLNB ultrasound with FNAC revealed summary sensitivity of 18.0% (95% CI 3.58% to 56.5%) and specificity of 99.8% (95% CI 99.1% to 99.9%) (1164 participants; 259 cases). Four studies demonstrated lower sensitivity (10.2%, 95% CI 4.31% to 22.3%) and specificity (96.5%,95% CI 87.1% to 99.1%) for PET-CT before SLNB (170 participants, 49 cases). When these data are translated to a hypothetical cohort of 1000 people eligible for SLNB, 237 of whom have nodal metastases (median prevalence), the combination of ultrasound with FNAC potentially allows 43 people with nodal metastases to be triaged directly to adjuvant therapy rather than having SLNB first, at a cost of two people with false positive results (who are incorrectly managed). Those with a false negative ultrasound will be identified on subsequent SLNB.Limited test accuracy data were available for whole body imaging via PET-CT for primary staging or re-staging for disease recurrence, and none evaluated MRI. Twenty-four studies evaluated whole body imaging. Six of these studies explored primary staging following a confirmed diagnosis of melanoma (492 participants), three evaluated re-staging of disease following some clinical indication of recurrence (589 participants), and 15 included mixed or not clearly described population groups comprising participants at a number of different points on the clinical pathway and at varying stages of disease (1265 participants). Results for whole body imaging could not be translated to a hypothetical cohort of people due to paucity of data.Most of the studies (6/9) of primary disease or re-staging of disease considered PET-CT, two in comparison to CT alone, and three studies examined the use of ultrasound. No eligible evaluations of MRI in these groups were identified. All studies used histological reference standards combined with follow-up, and two included FNAC for some participants. Observed accuracy for detection of any metastases for PET-CT was higher for re-staging of disease (summary sensitivity from two studies: 92.6%, 95% CI 85.3% to 96.4%; specificity: 89.7%, 95% CI 78.8% to 95.3%; 153 participants; 95 cases) compared to primary staging (sensitivities from individual studies ranged from 30% to 47% and specificities from 73% to 88%), and was more sensitive than CT alone in both population groups, but participant numbers were very small.No conclusions can be drawn regarding routine imaging of the brain via MRI or CT.

AUTHORS' CONCLUSIONS

Review authors found a disappointing lack of evidence on the accuracy of imaging in people with a diagnosis of melanoma at different points on the clinical pathway. Studies were small and often reported data according to the number of lesions rather than the number of study participants. Imaging with ultrasound combined with FNAC before SLNB may identify around one-fifth of those with nodal disease, but confidence intervals are wide and further work is needed to establish cost-effectiveness. Much of the evidence for whole body imaging for primary staging or re-staging of disease is focused on PET-CT, and comparative data with CT or MRI are lacking. Future studies should go beyond diagnostic accuracy and consider the effects of different imaging tests on disease management. The increasing availability of adjuvant therapies for people with melanoma at high risk of disease spread at presentation will have a considerable impact on imaging services, yet evidence for the relative diagnostic accuracy of available tests is limited.

Positron emission tomography/computed tomography imaging appearance of benign and classic “do not touch” osseous lesions

BACKGROUND

Classic “do not touch” and benign osseous lesions are sometimes detected on ¹⁸-F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) studies. These lesions are often referred for biopsy because the physician interpreting the PET/CT may not be familiar with the spectrum of ¹⁸F-FDG uptake patterns that these lesions display.

AIM

To show that “do not touch” and benign osseous lesions can have increased ¹⁸F-FDG uptake above blood-pool on PET/CT; therefore, the CT appearance of these lesions should dictate management rather than the standardized uptake values (SUV).

METHODS

This retrospective study evaluated 287 independent patients with 287 classic “do not touch” (benign cystic lesions, insufficiency fractures, bone islands, bone infarcts) or benign osseous lesions (hemangiomas, enchondromas, osteochondromas, fibrous dysplasia, Paget’s disease, osteomyelitis) who underwent ¹⁸F-FDG positron emission tomography/computed tomography (PET/CT) at a tertiary academic healthcare institution between 01/01/2006 and 12/1/2018. The maximum and mean SUV, and the ratio of the maximum SUV to mean blood pool were calculated. Pearson’s correlations between lesion size and maximum SUV were calculated.

RESULTS

The ranges of the maximum SUV were as follows: For hemangiomas (0.95-2.99), bone infarcts (0.37-3.44), bone islands (0.26-3.29), enchondromas (0.46-2.69), fibrous dysplasia (0.78-18.63), osteochondromas (1.11-2.56), Paget’s disease of bone (0.93-5.65), insufficiency fractures (1.06-12.97) and for osteomyelitis (2.57-12.64). The range of the maximum SUV was lowest for osteochondromas (maximum SUV 2.56) and was highest for fibrous dysplasia (maximum SUV of 18.63). There was at least one lesion that demonstrated greater ¹⁸F-FDG avidity than the blood pool amongst each lesion type, with the highest maximum SUV ranging from 9.34 times blood pool mean (osteomyelitis) to 1.42 times blood pool mean (hemangiomas). There was no correlation between the maximum SUV and the lesion size except for enchondromas. Larger enchondromas had higher maximum SUV (r = 0.36, P = 0.02).

CONCLUSION

The classic “do not touch” lesions and classic benign lesions can be ¹⁸F-FDG avid. The CT appearance of these lesions should dictate clinical management rather than the maximum SUV.

Cost-effectiveness of second-line diagnostic investigations in patients included in the DANTE trial: a randomized controlled trial of lung cancer screening with low-dose computed tomography

AIM

The aim of this study was to analyze the economic efficiency of second-line diagnostic investigations in patients with undetermined lung nodules.

PARTICIPANTS AND METHODS

A retrospective review of all surgical cases included in the DANTE trial from 2001 to 2006 for lung cancer screening was performed. Overall, 217 patients and 261 lung nodules were analyzed. The cohort was divided into patients investigated with PET and/or computed tomography (CT)-guided biopsy (PET-CTB protocol; N=100), compared with those assessed with serial low-dose CT scans (standard protocol; N=161). Outpatient's and inpatient's costs were expressed in euros and derived from the Italian National Health Service. Ineffective costs were defined as the cost of procedures that lead to avoidable surgical intervention.

RESULTS

The diagnostic accuracy of the two protocols was 91% for the standard (sensitivity 100%, specificity 91%, positive predictive value 26%, and negative predictive value 100%) and 90% for the PET-CTB protocol (sensitivity 98%, specificity 81%, positive predictive value 85%, and negative predictive value 97%). Average costs for outpatient's diagnostics were 694 and 1.462 euros, respectively, for the standard and PET-CTB protocol. Average inpatient's costs for both protocols were 12.121 euros. The two protocols showed comparable effectiveness in terms of outpatient's costs (94 and 90%, respectively; P=0.252). Inpatient's costs were effective in 36% of cases monitored according to the standard protocol compared with 85% of patients investigated with PET-CTB protocol. Ineffective costs corresponded to 64 and 15%, respectively (P<0.0001).

CONCLUSION

Despite a higher average cost for outpatient's diagnostics, the implementation of PET imaging with or without CT-guided needle biopsy in the workup of suspicious lung nodules results in reduced unnecessary harm and costs related to inpatient's procedures.

The role of PET/CT in the management of patients affected by head and neck tumors: a review of the literature

The management of head and neck tumor (HNSCC) has been changing over the years, especially due to the aid of imaging techniques that help physicians to attain a correct diagnosis. These techniques represent a valuable tool to help tailor treatment and during follow-up of patients affected by malignancies. The aim of this review is to summarize the results of the most recent and relevant studies about the use of PET imaging in HNSCCs. This review is divided into six chapters: (1) The role of PET/CT in the pre-treatment phase; (2) PET/CT and radiotherapy planning; (3) PET/CT in the post-treatment setting; (4) PET/CT and SUVmax for prediction of prognosis; (5) miscellanea on the utility of PET in specific HNSCCs; (6) non-FDG PET tracers used in HNSCC. Promising results have been obtained so far. Despite the encouraging outcomes, more investigations are needed to warrant the value of this technique, especially in the pre-treatment setting.

PET-CT imaging in patients with chronic sternal wound infections prior to reconstructive surgery: A case series

Late presenting and recurrent sternal wound infections post-sternotomy are difficult to treat, with the clinical picture not necessarily reflecting the underlying problem. As a result of our experience, we suggest that these chronic cases should be managed using a different algorithm to acute sternal wound infection. Positron emission tomography combined with computerized tomography (PET-CT) imaging may be potentially useful in enabling accurate localization of disease sites, which guides adequate debridement prior to definitive reconstruction. It may also allow for disease surveillance and monitoring of the response to antimicrobial treatment. We present three cases which support the need for pre-operative imaging using PET-CT.

PET/CT Is Complementary to Fine-Needle Aspiration Cytology in Assessment of Irradiated Neck in Head and Neck Cancers

Background. Accurate assessment of irradiated neck in squamous cell carcinoma of the head and neck (HNSCC) is essential. Fine-needle aspiration cytology is often performed for suspicious lesions but it is limited by its low negative predictive value (NPV). We postulated that F-18 fluorodeoxyglucose (FDG) positron emission tomography combined with computed tomography (PET/CT) can overcome this limitation by its high NPV value and allow for a more accurate assessment of irradiated neck in HNSCC. Methods. Fifty-four HNSCC patients were included for the study. They all received previous irradiation to the neck. Clinical characteristics, details of radiotherapy, PET/CT results, follow-up findings, and final histological diagnosis were analyzed. Results. The sensitivity, specificity, positive predictive value (PPV), and NPV were 95.8%, 96.7%, 95.8%, and 96.7%, respectively. Age, sex, radiation dose, interval between PET/CT and radiotherapy completion, nature of radiotherapy, and use of second course of radiotherapy were not found to affect diagnostic accuracy of PET/CT. A new algorithm for investigation of masses in irradiated neck is proposed. Conclusions. PET/CT is an effective diagnostic tool and has a complementary role to FNAC in the management of irradiated neck in head and neck cancers, particularly in cases where suspicious lesions were identified but FNAC showed negative results.

Clinical impact of (18)F-FDG PET-CT in recurrent stage III/IV melanoma: a tertiary centre Specialist Skin Cancer Multidisciplinary Team (SSMDT) experience

Objectives

To assess the clinical impact of ¹⁸F-fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET-CT) compared with contrast-enhanced computed tomography (CECT) in patients referred via the Specialist Skin Cancer Multidisciplinary Team (SSMDT) with recurrent stage III/IV malignant melanoma (MM).

Methods

Forty-five patients were referred for further evaluation with FDG PET-CT. Findings on FDG PET-CT were compared with prior CECT and the clinical impact on subsequent management decisions was determined retrospectively. A major clinical impact was defined as a change in treatment plan resulting from identification of additional sites of disease or by characterisation of indeterminate findings on prior imaging. A minor impact was defined as confirmation of known sites of disease as identified on prior CECT.

Results

Fifty-one PET-CT examinations were performed. FDG PET-CT had a major clinical impact in 21 cases (41.2 %), of which 18 examinations were performed in patients with proven or suspected stage IV MM. FDG PET-CT had a minor impact in 23 cases (45.1 %), and there were five false-positive cases (9.8 %) and two false-negative cases (3.9 %).

Conclusion

FDG PET-CT is an effective tool in recurrent stage III/IV MM with a significant clinical impact on management decisions in patients who are appropriately referred via the highly specialised forum of the SSMDT.

Key Points

• FDG PET-CT is an effective tool in recurrent stage III/IV malignant melanoma.

• FDG PET-CT has a significant clinical impact on management decisions.

• Effective use of FDG PET-CT is via referral from the Specialist Skin Cancer Multidisciplinary Team.

Should positron emission tomography/computed tomography be the first rather than the last test performed in the assessment of cancer?

Cancer is a major cause of illness and death in Western society and is associated with a heavy concomitant economic burden. Although use of imaging comprises only a small proportion of the fiscal impact of cancer, its use has been increasing over recent decades, causing concern amongst funders of health care and efforts to constrain the use of new imaging tests with a relatively high unit cost. In clinical practice, positron emission tomography/computed tomography (PET/CT) is generally performed when less expensive tests have left some uncertainty regarding appropriate management. In this setting, its utility relates to provision of incremental diagnostic information. However, given that superior diagnostic information can positively affect patient management, wherein the majority of costs reside, it may be both more efficient and cost effective to go directly to the most accurate investigation in certain situations. For PET/CT, the ability to provide more accurate assessment of metastatic status than is available from conventional diagnostic paradigms provides a rationale for its independent rather than incremental use in patients presenting with either a high likelihood of malignancy or proven malignancy of a locally advanced nature and an accordingly high risk of metastatic disease. A randomized trial design is described that could be used to test this hypothesis.

Cost-effectiveness of adding FDG-PET or CT to the diagnostic work-up of patients with stage III melanoma

OBJECTIVE

The aim of this prospective study was to assess predictive value of fludeoxyglucose-positron emission tomography (FDG-PET) and computed tomography (CT) and to analyze their cost-effectiveness in several diagnosis-treatment combinations.

BACKGROUND

The incidence of melanoma continues to rise. A proportion will present or recur with lymph node metastases (American Joint Committee on Cancer/Union for International Cancer Control stage III). To detect distant metastases, CT and/or FDG-PET are available. However, few studies have assessed their value and costs in stage III.

METHODS

All consecutive patients with melanoma with palpable, proven lymph node metastases (2003-2008) referred for examination with FDG-PET and CT were prospectively included. Sensitivity, specificity, and accuracy, and positive predictive value (PPV) and negative predictive value (NPV) were calculated. In economic evaluation, the costs of diagnostic work-up with and without FDG-PET and CT were compared.

RESULTS

Overall, 253 patients with melanoma were included. FDG-PET showed a higher sensitivity than CT: 86.1% compared with 78.2%. Specificity was higher for CT (93.7%) compared with FDG-PET (93.1%). Overall, FDG-PET showed a higher PPV and NPV. Cost-consequence analysis showed that adding CT (True-Positive upstaging in 61 patients) to diagnostic work-up decreased cost by 5.5%, adding FDG-PET (True-Positive upstaging in 68 patients) increased cost by 7.2%, and adding both (True-Positive upstaging in 78 patients) increased cost by 15.1%.

CONCLUSIONS

In this study, FDG-PET had higher sensitivity and predictive value, whereas CT had a higher specificity. Adding one of these diagnostic tools improved the staging of stage III patients with less than 10% cost increase. A proposal for stage-specific use of imaging modalities for clinicians caring for patients with melanoma is presented.

Cost-effectiveness analysis of amino acid PET-guided surgery for supratentorial high-grade gliomas

High-grade gliomas are brain tumors associated with a devastating prognosis. Recent studies have indicated that the combined use of amino acid PET and MRI is superior to MRI alone to plan the surgical resection of high-grade gliomas. The aim of the study was to analyze the cost-effectiveness of the use of amino acid PET for the surgical resection of high-grade gliomas, compared with MRI alone, from the perspective of the national health insurance in Germany.

METHODS

A decision-tree model was set up to compare 2 strategies: the use of MRI alone and the combined use of MRI and PET for surgical resection of high-grade gliomas. For the analysis, 2 scenarios were calculated: a baseline scenario and a more expensive scenario, accounting for disease severity. To test the robustness of the results, probabilistic sensitivity analyses using Monte Carlo simulation were calculated.

RESULTS

Compared with MRI alone, the combined use of MRI and PET showed an incremental cost-effectiveness ratio of €2,948 (€1 ~ U.S.$1.3)per life-year gained for the baseline scenario and an incremental cost-effectiveness ratio of €4,105 per life-year gained for the admissible-charge-rate scenario. In the probabilistic sensitivity analysis in about 60% of the iterations, the combined use of PET and MRI was superior to MRI alone when assuming a willingness-to-pay threshold of €30,000.

CONCLUSION

The model indicates that the combined use of MRI and PET may be cost-effective. The results of this analysis have to be considered carefully because there was only limited empiric evidence for several input parameters.

Systematic review of the cost-effectiveness of positron-emission tomography in staging of non--small-cell lung cancer and management of solitary pulmonary nodules

Implementation of positron-emission tomography (PET) is variable depending on jurisdiction in part due to uncertainty about cost-effectiveness. Our objective was to perform a systematic review describing cost-effectiveness of PET in staging of non-small-cell lung cancer (NSCLC) and management of solitary pulmonary nodules (SPN). Systematic literature searches were conducted using separate search strategies for multiple databases. Our validity criteria included measurement of study quality by means of the validated Quality of Health Economic Studies (QHES) instrument. Metrics such as mean PET costs, median average cost savings per patient, incremental cost-effectiveness ratio based on life years saved and quality-adjusted life years were calculated. Eighteen studies met our inclusion criteria with average QHES scores > 75. Studies were primarily based on the national health insurance payer perspective from 10 different countries. Cost-effectiveness was assessed primarily using decision-tree modeling and sensitivity analysis to determine the effects of changing variables on expected cost and life expectancy. After adjusting for currency exchange rates and inflation to 2010 United States dollars, the mean cost of PET was $1478. The cost-effectiveness metrics used in these studies were variable depending on sensitivity and specificity of diagnostic tests used in the models, probability of malignancy, and baseline strategy. Despite observed study heterogeneity, the consensus of these studies conclude that the additional information gained from PET imaging in the staging of NSCLC and diagnosis of SPNs is worth the cost in context of proper medical indications.

Delivering affordable cancer care in high-income countries

The burden of cancer is growing, and the disease is becoming a major economic expenditure for all developed countries. In 2008, the worldwide cost of cancer due to premature death and disability (not including direct medical costs) was estimated to be US$895 billion. This is not simply due to an increase in absolute numbers, but also the rate of increase of expenditure on cancer. What are the drivers and solutions to the so-called cancer-cost curve in developed countries? How are we going to afford to deliver high quality and equitable care? Here, expert opinion from health-care professionals, policy makers, and cancer survivors has been gathered to address the barriers and solutions to delivering affordable cancer care. Although many of the drivers and themes are specific to a particular field-eg, the huge development costs for cancer medicines-there is strong concordance running through each contribution. Several drivers of cost, such as over-use, rapid expansion, and shortening life cycles of cancer technologies (such as medicines and imaging modalities), and the lack of suitable clinical research and integrated health economic studies, have converged with more defensive medical practice, a less informed regulatory system, a lack of evidence-based sociopolitical debate, and a declining degree of fairness for all patients with cancer. Urgent solutions range from re-engineering of the macroeconomic basis of cancer costs (eg, value-based approaches to bend the cost curve and allow cost-saving technologies), greater education of policy makers, and an informed and transparent regulatory system. A radical shift in cancer policy is also required. Political toleration of unfairness in access to affordable cancer treatment is unacceptable. The cancer profession and industry should take responsibility and not accept a substandard evidence base and an ethos of very small benefit at whatever cost; rather, we need delivery of fair prices and real value from new technologies.

Clinical impact of FDG PET-CT in patients with potentially operable metastatic colorectal cancer

AIM

To assess the clinical impact of 2-[(18)F]-fluoro-2-deoxy-d-glucose (FDG) positron-emission tomography-computed tomography (PET-CT) in patients with potentially resectable metastatic colorectal cancer.

MATERIALS AND METHODS

One hundred and two patients with potentially resectable metastatic colorectal cancer underwent FDG PET-CT in addition to conventional imaging over an 18-month period. The findings were compared to conventional imaging, with histological or clinico-radiological validation. The impact on subsequent management was evaluated using information from clinico-radiological databases.

RESULTS

Of 102 patients (mean age 67 years, range 27-85 years), 94 had liver, five had isolated lung, and three had limited peritoneal metastases. In 31 patients (30%) PET-CT had a major impact on subsequent management, by correctly clarifying indeterminate lesions on conventional imaging as inoperable metastatic disease in 16 patients, detecting previously unsuspected metastatic disease in nine patients, identifying occult second primary tumours in three patients, and correctly down-staging three patients. PET-CT had a minor impact in 12 patients (12%), no impact in 49 cases (48%), and a potentially negative impact in 10 cases (10%). Following PET-CT, 36 (35%) patients were no longer considered for surgery. Of those remaining operative 45 of 66 (68%) underwent potentially curative metastatic surgery. In this cohort PET-CT saved 16 futile laparotomies.

CONCLUSION

FDG PET-CT has a valuable role in selected patients with metastatic colorectal cancer by improving staging accuracy and characterizing indeterminate lesions and helps triage patients to the appropriate treatment.

The value of 18F-FDG-PET/CT imaging for sinonasal malignant melanoma

The aim this study was to evaluate imaging findings using position emission tomography (PET) in combination with computed tomography (CT) and 18F-fluorodeoxyglucose ((18)F-FDG) in sinonasal malignant melanoma (SNMM) of the head and neck in a retrospective analysis of a consecutive cohort of patients. (18)F-FDG-PET/CT examinations were performed for initial staging and compared with CT or magnetic resonance tomography (MRI), and (18)F-FDG-PET alone. Medical records were reviewed retrospectively with regard to the location and the size of the tumor. Furthermore, locoregional and distant metastases with a consecutive change in therapy detected by (18)F-FDG-PET/CT were assessed. Ten patients suffering from sinonasal malignant melanoma were staged and followed by (18)F-FDG-PET/CT imaging. A total of 34 examinations were obtained. (18)F-FDG-PET/CT depicted all primary tumors adequately. Aside from one cerebral metastasis all regional and distant metastases were truly identified by using this method. In summary, if available, (18)F-FDG-PET/CT is a valuable imaging modality for staging and re-staging sinonasal malignant melanoma to evaluate expansion of the primary tumor, locoregional disease, and distant metastases.

Does Medicare Have an Implicit Cost-Effectiveness Threshold?

Background. Despite the huge cost of the program, the Centers for Medicare and Medicaid Services (CMS) has maintained a policy that cost-effectiveness is not considered in national coverage determinations (NCDs). Objective. To assess whether an implicit cost-effectiveness threshold exists and to determine if economic evidence has been considered in previous NCDs. Methods. A literature search was conducted to identify estimates of cost-effectiveness relevant to each NCD from 1999—2007 (n = 103). The economic evaluation that best represented each coverage decision was included in a review of the cost-effectiveness of medical interventions considered in NCDs. Results. Of the 64 coverage decisions determined to have a corresponding cost-effectiveness estimate, 49 were associated with a positive coverage decision and 15 with a noncoverage decision. Of the positive decisions, 20 were associated with an economic evaluation that estimated the intervention to be dominant (costs less and was more effective than the alternative), 12 with an incremental cost-effectiveness ratio (ICER) of less than $50,000, 8 with an ICER greater than $50,000 but less than $100,000, and 9 with an ICER greater than $100,000. Fourteen of the sample of 64 decision memos cited or discussed cost-effectiveness information. Conclusions. CMS is covering a number of interventions that do not appear to be cost-effective, suggesting that resources could be allocated more efficiently. Although the authors identified several instances where cost-effectiveness evidence was cited in NCDs, they found no clear evidence of an implicit threshold.

Economic evaluation of PET and PET/CT in oncology: evidence and methodologic approaches

PET and PET/CT have changed the diagnostic algorithm in oncology. Health care systems worldwide have recently approved reimbursement for PET and PET/CT for staging of non-small cell lung cancer and differential diagnosis of solitary pulmonary nodules because PET and PET/CT have been found to be cost-effective for those uses. Additional indications that are covered by health care systems in the United States and several European countries include staging of gastrointestinal tract cancers, breast cancer, malignant lymphoma, melanoma, and head and neck cancers. Regarding these indications, diagnostic effectiveness and superiority over conventional imaging modalities have been shown, whereas cost-effectiveness has been demonstrated only in part. This article reports on the current knowledge of economic evaluations of PET and PET/CT in oncologic applications. Because more economic evaluations are needed for several clinical indications, we also report on the methodologies for conducting economic evaluations of diagnostic tests and suggest an approach toward the implementation of these tests in future clinical studies.

Meta-analysis of the performance of (18)F-FDG PET in cutaneous melanoma

INTRODUCTION

The aim of this study was to perform a systematic review of the literature to evaluate the accuracy of FDG-PET in staging and restaging of cutaneous melanoma.

METHODS

Systematic methods were used to identify, select, and evaluate the methodologic quality of the studies as well as to summarize the overall findings of sensitivity and specificity. The search strategy consisted of identifying studies published between 2000 and 2006. Inclusion criteria were studies that evaluated the diagnostic performance of FDG-PET in staging/restaging of cutaneous melanoma. The results were compared and pooled with a meta-analysis published previously that included studies published until 1999. The meta-analysis included 95% confidence intervals (CI) of sensitivity, specificity, likelihood-ratio (LR), and diagnostic-odds-ratio (DOR).

RESULTS

The quantitative meta-analysis included 24 studies that were analysed in two groups: eight studies were included only in the regional staging analysis (group I), 13 studies were included only in the detection of distant metastases analysis (group II), and three studies were included in both analyses. Compliance with the methodologic-quality criteria was acceptable. We analysed the results of data presented in patients, lesions, basins, lymph-nodes, areas, and scans. Regarding the performance of FDG-PET in the detection of metastases, the pooled studies presented homogeneity for the negative-LR (0.15; 95% CI, 0.10-0.22) when analyzing lesions. When analyzing scans, there was global homogeneity for specificity (0.86; 95% CI, 0.77-0.92), positive-LR (5.86; 95% CI, 3.64-9.43), and DOR (37.89; 95% CI, 15.80-90.86). The pooled studies presented heterogeneity for the other items analysed. Regarding the detection of regional metastases, when analyzing lymph-nodes there was global homogeneity for specificity (0.99; 95% CI, 0.97-0.99; P = 0.101). The meta-regression evidenced that the variable that most influenced the DOR of the different studies and that can explain the heterogeneity was the year of publication; this may be related to the evolution of PET technology and an improvement of sensitivity/specificity.

CONCLUSION

FDG-PET is not useful in the evaluation of regional metastases, as it does not detect microscopic disease. However, FDG-PET could be useful in the detection of distant metastases, and could suggest its utility in the management of patients with cutaneous melanoma.

Clinical Applications of FDG PET and PET/CT in Head and Neck Cancer

18F-FDG PET plays an increasing role in diagnosis and management planning of head and neck cancer. Hybrid PET/CT has promoted the field of molecular imaging in head and neck cancer. This modality is particular relevant in the head and neck region, given the complex anatomy and variable physiologic FDG uptake patterns. The vast majority of 18F-FDG PET and PET/CT applications in head and neck cancer related to head and neck squamous cell carcinoma. Clinical applications of 18F-FDG PET and PET/CT in head and neck cancer include diagnosis of distant metastases, identification of synchronous 2nd primaries, detection of carcinoma of unknown primary and detection of residual or recurrent disease. Emerging applications are precise delineation of the tumor volume for radiation treatment planning, monitoring treatment, and providing prognostic information. The clinical role of 18F-FDG PET/CT in N0 disease is limited which is in line with findings of other imaging modalities. MRI is usually used for T staging with an intense discussion concerning the preferable imaging modality for regional lymph node staging as PET/CT, MRI, and multi-slice spiral CT are all improving rapidly. Is this review, we summarize recent literature on 18F-FDG PET and PET/CT imaging of head and neck cancer.

Role of functional imaging in head and neck squamous cell carcinoma: fluorodeoxyglucose positron emission tomography and beyond

Positron emission tomography (PET) has emerged as an integral diagnostic tool in the management of head and neck squamous cell carcinoma (HNSCC). This article reviews the usefulness and ongoing dilemmas of fluorine-18 fluorodeoxyglucose (18-F FDG) PET and FDG PET/CT in HNSCC. In addition, it examines the potential role of novel markers and biologic characterization of disease, which in the future may assist in targeted therapeutic strategies.

Abnormal FDG uptake on 18F-fluorodeoxyglucose positron emission tomography in patients with cancer diagnosis: case reports of tuberculous lymphadenitis

Although 18F-FDG-PET is very sensitive for a variety of malignancies, it can lack specificity. In addition to malignant tissue, any active infectious or inflammatory process can demonstrate FDG avidity. We report 3 patients with different types of cancer who had abnormal 18F-FDG uptake on PET scan caused by tuberculous lymphadenitis. All were found to have incidental multiple lymph adenopathies with increased FDG uptake on PET scan. All three patients were proved to have tuberculosis lymphadenitis by pathologic examination and were successfully treated with anti-tuberculous therapy.

The cost-effectiveness of 18FDG-PET in selecting patients with suspicion of recurrent laryngeal carcinoma after radiotherapy for direct laryngoscopy

The aim of this study was to estimate the cost-effectiveness of ¹⁸FDG-PET in the selection for direct laryngoscopy in patients with suspicion of recurrent laryngeal carcinoma after radiotherapy. The direct medical costs of 30 patients with suspicion of a recurrence were calculated from the first visit where suspicion was raised until one year after. A conventional strategy, in which all these patients underwent direct laryngoscopy, was compared to an ¹⁸FDG-PET strategy in which only patients with a positive or equivocal ¹⁸FDG-PET underwent direct laryngoscopy. A sensitivity analysis was performed to examine the influence of the type of camera and ‘setting’. The mean costs of an ¹⁸FDG-PET strategy were €399 less than a direct laryngoscopy strategy. The type of camera and setting had no influence. In patients with suspicion for recurrent laryngeal carcinoma after radiotherapy, ¹⁸FDG-PET seems to be effective and less costly in selecting patients for direct laryngoscopy.

Assessing short-term effects and costs at an early stage of innovation: the use of positron emission tomography on radiotherapy treatment decision making

OBJECTIVES

Positron emission tomography (PET) is an innovative imaging tool. Associated with computed tomography (CT), it allows a better definition for the tumor volume for radiotherapy, compared with CT only. The aim of this study was to assess the effects of PET on resource allocation (costs and savings) and on the choice of the following treatment in radiotherapy.

METHODS

In 2004 and 2005, 209 patients were enrolled (97 patients with Hodgkin's disease and 112 with non-small cell lung cancer) in a national study conducted in eight hospitals. Two treatment decisions made on the basis of CT only or CT associated with PET, were compared in a prospective study where each subject was his/her own control. The direct medical cost of using PET was assessed by microcosting, using data collected from specific questionnaires. The costs of new tests and the costs and savings associated with changes in the chosen treatment were calculated on the basis of reimbursement rates.

RESULTS

The mean cost of using PET was approximately euro 800 per patient (50 percent for the radionuclide 18F-FDG [2-[18F]fluoro-2-deoxy-D-glucose]). Radiotherapy treatments were modified for 10 percent of patients with Hodgkin's disease versus 40 percent of patients with lung cancer. Overall, the use of PET induced both increases and decreases in the mean cost per patient: the net effect was a euro 425 and euro 931 cost increase in lung cancer and Hodgkin's disease, respectively.

CONCLUSIONS

The use of PET for radiotherapy decision making seems more valuable for lung cancer than for Hodgkin's disease, both in terms of costs and changes in radiotherapy treatment. This result might help policy makers for prioritization.

Noninvasive staging of non-small cell lung cancer: ACCP evidenced-based clinical practice guidelines (2nd edition)

BACKGROUND

Correctly staging lung cancer is important because the treatment options and the prognosis differ significantly by stage. Several noninvasive imaging studies including chest CT scanning and positron emission tomography (PET) scanning are available. Understanding the test characteristics of these noninvasive staging studies is critical to decision making.

METHODS

Test characteristics for the noninvasive staging studies were updated from the first iteration of the lung cancer guidelines using systematic searches of the MEDLINE, HealthStar, and Cochrane Library databases up to May 2006, including selected metaanalyses, practice guidelines, and reviews. Study designs and results are summarized in evidence tables.

RESULTS

The pooled sensitivity and specificity of CT scanning for identifying mediastinal lymph node metastasis were 51% (95% confidence interval [CI], 47 to 54%) and 85% (95% CI, 84 to 88%), respectively, confirming that CT scanning has limited ability either to rule in or exclude mediastinal metastasis. For PET scanning, the pooled estimates of sensitivity and specificity for identifying mediastinal metastasis were 74% (95% CI, 69 to 79%) and 85% (95% CI, 82 to 88%), respectively. These findings demonstrate that PET scanning is more accurate than CT scanning. If the clinical evaluation in search of metastatic disease is negative, the likelihood of finding metastasis is low.

CONCLUSIONS

CT scanning of the chest is useful in providing anatomic detail, but the accuracy of chest CT scanning in differentiating benign from malignant lymph nodes in the mediastinum is poor. PET scanning has much better sensitivity and specificity than chest CT scanning for staging lung cancer in the mediastinum, and distant metastatic disease can be detected by PET scanning. With either test, abnormal findings must be confirmed by tissue biopsy to ensure accurate staging.

Clinical impact of positron emission tomography (PET) with (18F)fluorodeoxyglucose (FDG) in head and neck tumours

CONCLUSION

PET plays an important role in staging, on suspicion of recurrence and for detection of occult primary tumours in the head and neck.

OBJECTIVE

Since 1998 we have used positron emission tomography (PET) with (18F)fluorodeoxyglucose (FDG) to assess selected patients. This procedure has often helped in making decisions on staging and treatment.

PATIENTS AND METHODS

The case records of the first 80 patients (104 PET examinations) were studied retrospectively.

RESULTS

A total of 39 examinations were performed for staging. PET detected all primary tumours except two (stage T1), and staging was adjusted after 13%. In all, 33 PET examinations were performed on suspicion of recurrent tumour. In 52% of these PET determined further treatments; in 21% PET had a direct impact on the surgical planning. In 18 patients with metastases from an occult primary tumour, PET detected 39% of those tumours; in 22% it was the sole modality to do so. No recurrences or second primary tumours were detected when PET was used for follow-up of clinically cured patients. Results were similar when squamous cell carcinomas (SCCs) were considered alone as compared to the complete material. The mean standardized uptake value (SUV) was higher for cases deemed tumour-positive than in negative cases.

The role of positron emission tomography in the management of recurrent colorectal cancer: a review

PURPOSE

Surgery remains the only option for potential cure in patients with recurrent colorectal cancer. Accurate staging modalities aid in the avoidance of futile surgery, which may result in considerable morbidity in patients with incurable disease. Current imaging techniques used in disease staging often are not sensitive enough to identify low-volume metastatic disease. This study reviews the role of positron emission tomography in the assessment of patients with suspected recurrent colorectal cancer.

METHODS

A literature search using the PubMed, MEDLINE, and Embase database was performed, locating English language articles on positron emission tomography, positron emission tomography, recurrent colon, and/or rectal cancer. The references of these papers were searched manually for further references.

RESULTS

Positron emission tomography is more sensitive and more specific than conventional diagnostic imaging for metastatic disease and local recurrence respectively. Studies confirm the superior ability of positron emission tomography scans compared with conventional diagnostic imaging in differentiating between scar tissue and invasive tumor. Positron emission tomography scanning is more sensitive and specific for the assessment of liver metastases (and probably in patients with lung metastasis) than conventional diagnostic imaging. Positron emission tomography is superior to conventional diagnostic imaging in the investigation of raised carcinoembryonic antigen in the postoperative patient and alters management in approximately 37 percent of patients with recurrent colorectal cancer. The limitations and cost effectiveness of positron emission tomography are discussed.

CONCLUSIONS

Positron emission tomography scanning is emerging as the imaging modality of choice for patients being considered for surgery for locally recurrent colorectal cancer. Positron emission tomography has the greatest impact by detecting unresectable disease and thereby averting inappropriate surgery. Despite the high set-up costs, its use seems to be cost effective.

PET in lymphoma

This review attempts to discuss the role of positron emission tomography (PET) imaging for staging, treatment response and follow-up of patients with lymphoma. The pitfalls and impact of PET imaging on the clinical management are also addressed.

The role of fluorodeoxyglucose, 18F-dihydroxyphenylalanine, 18F-choline, and 18F-fluoride in bone imaging with emphasis on prostate and breast

Diagnostic imaging has played a major role in the evaluation of patients with bone metastases. The imaging modalities have included bone scintigraphy, computed tomography, magnetic resonance imaging, and most recently PET/CT, which can be performed with different tracers, including fluorodeoxyglucose (FDG), 18F-fluoride, 18F-choline (FCH), and 18F-DOPA (dihydroxyphenylalanine). For most tumors the sensitivity of FDG in detecting bone metastases is similar to bone scintigraphy; additionally it can be used to monitor the response to chemotherapy and hormonal therapy. 18F-Fluoride may provide a more sensitive "conventional" bone scan and is superior for FDG nonavid tumors, but, nevertheless, FDG in "early disease" often has clear advantages over 18F-fluoride. Although more data need to be obtained, it appears that FCH is highly efficient in preoperative management regarding N and M staging of prostate cancer once metastatic disease is strongly suspected or documented. For neuroendocrine tumors and in particular in medullary thyroid cancer, DOPA is similar to 18F-fluoride in providing high quality information regarding the skeleton. Nevertheless, prospective studies with large patient groups will be essential to define the exact diagnostic role of FCH and DOPA PET in different clinical settings.

Integrated PET/CT: Current Applications and Future Directions

For the past 5 years, combined positron emission tomography (PET) and computed tomography (CT), or PET/CT, has grown because the PET portion provides information that is very different from that obtainable with other imaging modalities. However, the paucity of anatomic landmarks on PET images makes a consistent "hardware fusion" to anatomic cross-sectional data extremely useful. Clinical experience indicates a single direction: Addition of CT to PET improves specificity foremost, but also sensitivity, and the addition of PET to CT adds sensitivity and specificity in tumor imaging. Thus, PET/CT is a more accurate test than either of its individual components and is probably also better than side-by-side viewing of images from both modalities. The synergistic advantage of adding CT is that the attenuation correction needed for PET can also be derived from the CT data, an advantage not obtainable by integrating PET and magnetic resonance imaging. This makes PET/CT 25%-30% faster than PET alone with standard attenuation-correction methods, leading to higher patient throughput and a more comfortable examination, which typically last 30 minutes or less. Fluorodeoxyglucose (FDG) PET/CT appears to provide relevant information in the staging and therapy monitoring of many tumors, including lung carcinoma, mesothelioma, colorectal cancer, lymphoma, melanoma, and many others, with the notable exception of prostatic cancer. For prostatic cancer, choline derivatives may become useful radiopharmaceuticals. The published literature on the applications of FDG PET/CT in oncology is still limited, but several well-designed studies have demonstrated the benefits of PET/CT.

An audit of imaging test utilization for the management of lymphoma in an oncology hospital: implications for resource planning?

The purpose of this study was to assist with resource planning by examining the pattern of physician utilization of imaging procedures for lymphoma patients in a dedicated oncology hospital. The proportion of imaging tests ordered for routine follow up with no specific clinical indication was quantified, with specific attention to CT scans. A 3-month audit was performed. The reasons for ordering all imaging procedures (X-rays, CT scans, ultrasound, nuclear scan and MRI) were determined through a retrospective chart review. 411 lymphoma patients had 686 assessments (sets of imaging tests) and 981 procedures (individual imaging tests). Most procedures were CT scans (52%) and chest radiographs (30%). The most common reasons for ordering imaging were assessing response (23%), and investigating new symptoms (19%). Routine follow up constituted 21% of the assessments (142/686), and of these, 82% were chest radiographs (116/142), while 24% (34/142) were CT scans. With analysis restricted to CT scans (296 assessments in 248 patients), the most common reason for ordering CT scans were response evaluation (40%), and suspicion of recurrence and/or new symptom (23%). Follow-up CT scans done with no clinical indication comprised 8% (25/296) of all CT assessments. Staging CT scans were under-represented at 6% of all assessments. Imaging with CT scans for follow up of asymptomatic patients is infrequent. However, scans done for staging new lymphoma patients were unexpectedly low in frequency, due to scans done elsewhere prior to referral. This analysis uncovered utilization patterns, helped resource planning and provided data to reduce unnecessary imaging procedures.

Initial Staging of Lymphoma With Positron Emission Tomography and Computed Tomography

Lymphomas represent a diverse range of diseases with manifold presentations, outlook, and therapeutic approaches. Key to the modern management of lymphoma is accurate delineation of the extent of disease. The inability of computed tomography (CT) to identify the involvement of nonenlarged nodes and its relatively poor sensitivity in the detection of extra-nodal sites of involvement limit the performance of noninvasive staging techniques. Functional imaging techniques such as Ga-67 scintigraphy have been used for many years to improve the evaluation of patients with lymphoma. While providing complementary information to CT in many clinical settings, functional imaging has never had sufficient accuracy or localizing ability to seriously challenge conventional primary staging paradigms. (18)F-Fluorodeoxyglucose positron emission tomography (FDG PET), however, has been demonstrated to have both higher sensitivity and specificity than CT in many comparative series. Now that this technology also can be performed at the same time as structural imaging in the form of hybrid PET/CT devices, clinicians are rethinking the methods used to select, plan, and monitor therapy of lymphoma patients. In our institution, FDG PET/CT has become the preferred initial staging tool for patients with lymphoma.

Is There a Role for PET in the Evaluation of Subcentimeter Pulmonary Nodules?

There are little published data available at this time to determine the appropriate role of positron emission tomography (PET) in the evaluation of subcentimeter pulmonary nodules. The sensitivity for malignancy is lower in these smaller lesions, while one would expect the specificity to be higher. Given that the resolution of current generation PET scanners is only 5 to 6 mm, one will be very unlikely to gain useful information from PET for a lesion below 5 mm. For lesions 5 to 10 mm in size, useful information might be gained from PET in those deemed intermediate risk by CT criteria, but this remains to be established. A positive PET in a small, intermediate risk lesion might push one toward biopsy/excision, though a negative PET in such a lesion must be considered to provide no information whatsoever. Even with advances in PET technologies in the future, we feel it is unlikely that PET will evolve a major role in the evaluation of the subcentimeter nodule.

Functional Imaging in Lung Cancer

Accurate detection of the presence and extent of disease is vital in the management of non–small-cell lung cancer. While computed tomography and magnetic resonance imaging tend to be the routine diagnostic modalities used in the management of lung cancer, there have been significant advances in the field of functional and molecular imaging. In this article, we review the performance of the functional imaging techniques that are currently available for the evaluation of non–small-cell lung cancer. The techniques range from evaluation of glucose metabolism in tumors with fluorodeoxyglucose, to evaluation of proliferation with fluorothymidine and evaluation of tumor hypoxia with agents such as fluoromisonidazole. Magnetic resonance imaging with an emphasis on dynamic contrast enhancement of tumors as well as detecting of malignant lymph nodes with targeted contrast agents is discussed. Emerging technologies such as lung imaging fluorescence endoscopy are considered. The role of functional imaging in planning, predicting response to, and evaluating effects of, various therapies is explored.

Evaluation of extensive initial staging procedure in intermediate/high-risk melanoma patients

INTRODUCTION

Early diagnosis and treatment of metastases have been shown to improve overall survival of melanoma patients. The purpose of this study was to evaluate the impact of extensive initial staging, including positron emission tomography (PET) scan on the management of melanoma patients.

PATIENTS AND METHODS

Forty-three patients with intermediate/poor prognosis primary melanoma benefited from complementary excision and sentinel lymph node biopsy (SLB) after clinical and paraclinical staging (computed tomography, nuclear magnetic resonance and whole body fluorodeoxyglucose PET scan).

RESULTS

No systemic metastases were demonstrated, while the SLB procedure emphasized the presence of regional lymph node metastases in 10 patients as suggested by the PET scan in four patients (sensitivity of the PET scan 40%). These 10 patients with early diagnosed lymph node involvement benefited from early surgery and were included in adjuvant treatment protocols. A secondary primary cancer was fortuitously diagnosed and treated early in two patients.

CONCLUSIONS

The development of new adjuvant therapies and therapeutic procedures (specific and non-specific immunotherapy, gamma-knife radiosurgery, etc.) now raises the relevance of extensive staging in intermediate/poor prognosis melanoma patients. We confirm in our series that PET scan is not useful to detect micrometastasis and cannot replace SLB in initial regional staging. However, we show in our study that 12 of 43 patients were treated early or were included early in treatment protocols thanks to the extensive staging procedure. Nevertheless, it seems important to evaluate through larger prospective trials the real impact of these early diagnoses and new treatments on overall survival before defining new diagnostic and therapeutic guidelines.

Seeking a home for a PET, part 2: Defining the appropriate place for positron emission tomography imaging in the staging of patients with suspected lung cancer

In patients who have a high likelihood of having lung cancer, there is little role for positron emission tomography (PET) imaging for diagnosis of the primary lesion. The primary impact of PET imaging is in extrathoracic staging, but it should not replace a clinical evaluation by a physician experienced in lung cancer. PET imaging is most useful for confirmation of the presumed extrathoracic stage in patients with intermediate stages of lung cancer. The role of PET imaging is limited in patients with strong clinical signs of metastatic disease, or in patients with a clinical stage I lung cancer and a negative clinical evaluation. With regard to intrathoracic staging, PET imaging has a definite role in communities in which mediastinoscopy is not available, whereas the impact is limited in institutions in which invasive mediastinal staging is available. The data suggest that a positive PET result in the mediastinum should be confirmed by biopsy. A mediastinoscopy is also reasonable in patients with clinical stage III lung cancer who have no mediastinal PET uptake. It is unclear and controversial whether a biopsy is needed in patients with clinical stage II lung cancer who have no PET uptake in the mediastinum.