Consistency of FDG-PET accuracy and cost-effectiveness in initial staging of patients with Hodgkin lymphoma across jurisdictions

Fluorodeoxyglucose-positron emission tomography staging can replace bone marrow biopsy in Hodgkin's lymphoma. Results from Brazilian Hodgkin's Lymphoma Study Group

Objective

To investigate, in a large prospective multicenter study, whether 2-[18F]-fluoro-2-deoxy-d-glucose-positron emission tomography is sufficiently accurate to identify clinically important bone marrow involvement by Hodgkin's lymphoma to replace routine bone marrow biopsy in a developing tropical country.

Methods

Patients newly diagnosed with Hodgkin's lymphoma were recruited from six cancer centers in Brazil. All were staged by the results of positron emission tomography/computed tomography that were centrally reviewed and by iliac crest bone marrow biopsy. Patients were classified as having marrow disease if they had lymphoma identified by marrow biopsy histology or had focal 2-[18F]-fluoro-2-deoxy-d-glucose marrow uptake that resolved following chemotherapy.

Results

A total of 246 participants were recruited from six different centers and 62 (25.2%) were judged to have Hodgkin's lymphoma in the bone marrow. Positron emission tomography and biopsies were concordant in 206 patients (83%). Positron emission tomography correctly identified marrow disease in 59/62 patients (95.1%) and marrow biopsy in 25/62 patients (40.3%). In 22/62 (35.4%) patients, the two techniques were concordant in the diagnosis of marrow involvement. Of the forty discordant results, positron emission tomography found bone marrow involvement in 37 patients, upstaging 22 to stage IV and having an impact on therapeutic decision in nine cases given their reallocation from early to advanced stage. Three false negative positron emission tomography results were obtained with bone marrow biopsy giving positive findings. All three cases were classified as stage IV regardless of bone marrow findings implying no modification in the clinical management. The sensitivity, specificity and accuracy of positron emission tomography for detecting bone marrow disease were 95%, 100% and 98% and for bone marrow biopsy they were 40%, 100% and 84%, respectively.

Conclusion

We conclude that positron emission tomography can replace marrow biopsy in Brazilian patients with Hodgkin's lymphoma without compromising clinical management.

Systematic Review of Health Economic Evaluations of Diagnostic Tests in Brazil: How accurate are the results?

The aim of this study is to identify and characterize the health economic evaluations (HEEs) of diagnostic tests conducted in Brazil, in terms of their adherence to international guidelines for reporting economic studies and specific questions in test accuracy reports. We systematically searched multiple databases, selecting partial and full HEEs of diagnostic tests, published between 1980 and 2013. Two independent reviewers screened articles for relevance and extracted the data. We performed a qualitative narrative synthesis. Forty-three articles were reviewed. The most frequently studied diagnostic tests were laboratory tests (37.2%) and imaging tests (32.6%). Most were non-invasive tests (51.2%) and were performed in the adult population (48.8%). The intended purposes of the technologies evaluated were mostly diagnostic (69.8%), but diagnosis and treatment and screening, diagnosis, and treatment accounted for 25.6% and 4.7%, respectively. Of the reviewed studies, 12.5% described the methods used to estimate the quantities of resources, 33.3% reported the discount rate applied, and 29.2% listed the type of sensitivity analysis performed. Among the 12 cost-effectiveness analyses, only two studies (17%) referred to the application of formal methods to check the quality of the accuracy studies that provided support for the economic model. The existing Brazilian literature on the HEEs of diagnostic tests exhibited reasonably good performance. However, the following points still require improvement: 1) the methods used to estimate resource quantities and unit costs, 2) the discount rate, 3) descriptions of sensitivity analysis methods, 4) reporting of conflicts of interest, 5) evaluations of the quality of the accuracy studies considered in the cost-effectiveness models, and 6) the incorporation of accuracy measures into sensitivity analyses.

PET-Based Percutaneous Needle Biopsy

PET can be used to guide percutaneous needle biopsy to the most metabolic lesion, improving diagnostic yield. PET biopsy guidance can be performed using visual or software coregistration, electromagnetic needle tracking, cone-beam computed tomography (CT), and intraprocedural PET/CT guidance. PET/CT-guided biopsies allow the sampling of lesions that may not be clearly visible on anatomic imaging, or of lesions that are morphologically normal. PET can identify suspicious locations within complex tumors that are most likely to contain important diagnostic and prognostic information.

Dealing with bone marrow biopsies in the staging of classical Hodgkin lymphoma: an old issue revisited in the (18)F-fluorodeoxyglucose-positron emission tomography era

Bone marrow biopsy is recommended for staging of classical Hodgkin lymphoma. The aim of this study was to compare bone marrow evaluation by histology with that obtained by (18)F-fluorodeoxyglucose-positron emission tomography (FDG-PET). One hundred and three cases of Classical Hodgkin Lymphoma were reviewed. All patients were submitted to FDG-PET evaluation. Bone marrow biopsy results were compared with clinical data and FDG-PET results. Ninety-one cases had available bone marrow biopsies. Overall, there were 16 positive and one suspect case. In five cases, the FDG-PET scan was positive and biopsy was negative: 1/5 was found to correspond to a bone fracture, 3/5 showed marked reactive bone marrow changes and in 1/5 no explanation for the discrepancy was found. FDG-PET showed high sensitivity, supporting the idea that when it is negative, biopsy could be avoided. Care should be taken in patients with a positive FDG-PET, where confirmation by bone marrow biopsy should be recommended.

Cost-effectiveness of PET and PET/computed tomography: a systematic review

The development of clinical diagnostic procedures comprises early-phase and late-phase studies to elucidate diagnostic accuracy and patient outcome. Economic assessments of new diagnostic procedures compared with established work-ups indicate additional cost for 1 additional unit of effectiveness measure by means of incremental cost-effectiveness ratios when considering the replacement of the standard regimen by a new diagnostic procedure. This article discusses economic assessments of PET and PET/computed tomography reported until mid-July 2014. Forty-seven studies on cancer and noncancer indications were identified but, because of the widely varying scope of the analyses, a substantial amount of work remains to be done.

Cervical lymphadenopathy: study of 251 patients

Correct diagnosis of cervical lymphadenopathy is often a great challenge. The objective of this case study is to describe the distribution of the most common causes of unclear neck swellings presented in an ENT-Department and to evaluate the clinical history, examination and laboratory findings. In a retrospective study at the Department of Otorhinolaryngology, University Medical Center Homburg/Saar, 251 patients were enrolled with clinical and ultrasound signs of cervical lymphadenopathy as well as lymph node extirpation for histopathological evaluation. 127 patients (50.6 %) had a histological malignant finding. The distribution of the most common pathological conditions was as follows: Non-specific reactive hyperplasia n = 89 (35.5 %), metastases n = 86 (34.3 %), lymphoma n = 41 (16.3 %), granulomatous lesions n = 15 (6 %), abscess formations n = 5 (2 %), necrotic lymphadenitis and Castleman's disease one case of each, lymph node with normal architecture n = 7 (2.8 %), and neck masses mimicking lymphadenopathy n = 6 cases (2.4 %). The following factors identified by multivariate logistic regression were significantly associated to malignant lymphadenopathy: increasing age, generalized lymphadenopathy and history of malignant disorder, fixed neck masses and increasing diameter in ENT examination, bulky lesion, absence of hilus, blurred outer contour, protective role of the long form and decreasing Solbiati-index values by ultrasound B-Mode gray scale examination. Level II contained more benign lymphatic lesions, while the malignancy rate in level IV and V was enhanced. Laboratory parameters significantly associated to malignancies were CRP, LDH and thrombocytopenia. Patients with persisting cervical lymphadenopathy and over 3 weeks of antibiotic treatment should be considered for early biopsy, especially if some of the risk factors, pointed out in this study, are present.

FDG PET/MR for the assessment of lymph node involvement in lymphoma: initial results and role of diffusion-weighted MR

RATIONALE AND OBJECTIVES

The purpose of this study was to evaluate the sensitivity and specificity of positron emission tomography/magnetic resonance imaging (PET/MR) with 18F-fluorodeoxyglucose (FDG) for nodal involvement in malignant lymphoma.

MATERIALS AND METHODS

Twenty-seven patients with malignant lymphoma (16 men and 11 women; mean age, 45 years) were included in this retrospective study. The patients underwent FDG PET/MR after intravenous injection of FDG (176-357 MBq FDG, 282 MBq on average). Follow-up imaging and histology served as the standard of reference.

RESULTS

One-hundred and twenty-seven (18.1%) of 702 lymph node stations were rated as having lymphoma involvement based on the standard of reference. One-hundred and twenty-four (17.7%) of 702 lymph node stations were rated as positive by FDG PET/MR. The sensitivity and specificity of FDG PET/MR for lymph node station involvement were 93.8% and 99.4%.

CONCLUSIONS

FDG PET/MR is feasible for lymphoma staging and has a high sensitivity and specificity for nodal involvement in lymphoma. Comparison with PET/CT is necessary to determine whether FDG PET/MR can replace PET/CT for lymphoma staging.

Cost-effectiveness of Fluorine-18-Fluorodeoxyglucose positron emission tomography in tumours other than lung cancer: A systematic review

AIM: To systematically review published data on the cost-effectiveness of Fluorine-18-Fluorodeoxyglucose positron emission tomography (FDG-PET) or PET/computed tomography (PET/CT) in tumours other than lung cancer.

METHODS: A comprehensive literature search of studies published in PubMed/MEDLINE, Scopus and Embase databases through the 10^th of October in 2013 was carried out. A search algorithm based on a combination of the terms: (1) “PET” or “ PET/computed tomography (PET/CT)” or “positron emission tomography”; and (2) “cost-effectiveness” or “cost-utility” or “cost-efficacy” or “technology assessment” or “health technology assessment” was used. Only cost-effectiveness or cost-utility analyses in English language were included. Exclusion criteria were: (1) articles not within the field of interest of this review; (2) review articles, editorials or letters, conference proceedings; and (3) outcome evaluation studies, cost studies or health technology assessment reports. For each included study, information was collected concerning basic study, type of tumours evaluated, perspective/type of study, results, unit and comparison alternatives.

RESULTS: Sixteen studies were included. Head and neck tumours were evaluated in 4 articles, lymphoma in 4, colon-rectum tumours in 3 and breast tumours in 2. Only one article was retrieved for melanoma, oesophagus and ovary tumours. Cost-effectiveness results of FDG-PET or PET/CT ranged from dominated to dominant.

CONCLUSION: Literature evidence about the cost-effectiveness of FDG-PET or PET/CT in tumours other than lung cancer is still limited. Nevertheless, FDG-PET or PET/CT seems to be cost-effective in selective indications in oncology (staging and restaging of head and neck tumours, staging and treatment evaluation in lymphoma).

2-[18F]-fluoro-2-desoxy-D-glucose positron emission tomography initial staging impacts on survival in Hodgkin lymphoma

AIM: To assess the prognostic value and risk classification improvement of metabolic staging (MS) with Initial 2-[18F]-fluoro-2-desoxy-D-glucose positron emission tomography (FDG-PET) in initial staging of Hodgkin’s Lymphoma (HL) patients to predict 5 years overall survival (5y-OS) and event free survival (EFS).

METHODS: A total of 275 patients were included in this retrospective study, 155 patients were staged with conventional anatomical staging (AS), and 120 also submitted to MS (FDG-PET). Prognostic analysis compared 5y-OS and 5y-EFS of patients staged with AS and MS. Risk-adjusted models incorporated clinical risk factors, computed tomography and FDG-PET staging.

RESULTS: During the follow up of 267 evaluated patients, 220 (122 AS and 98 MS) achieved complete remission after first-line therapy (median follow-up: 70 ± 29 mo), treatment failure occurred in 79 patients and 34 died. The 5y-EFS for early vs advanced disease in AS patients was 79.3% and 66.7%, and 85.6% and 53.6% in MS patients, respectively (P < 0.01). The 5y-OS for early and advanced disease with AS was 91.3% and 81.5%, and 97.5% and 80.7% for patients staged with MS, respectively. Cox proportional hazards analysis demonstrated that FDG-PET added significant prognostic information and improved risk prediction (P = 0.02).

CONCLUSION: Initial staging FDG-PET could be used as an accurate and independent predictor of OS and EFS in HL, with impact in 5y-EFS and OS.

Hybrid imaging worldwide-challenges and opportunities for the developing world: a report of a Technical Meeting organized by IAEA

The growth in nuclear medicine, in the past decade, is largely due to hybrid imaging, specifically single-photon emission tomography-computed tomography (SPECT-CT) and positron emission tomography-computed tomography (PET-CT). Introduction and use of hybrid imaging has been growing at a fast pace. This has led to many challenges and opportunities to the personnel dealing with it. The International Atomic Energy Agency (IAEA) keeps a close watch on the trends in applications of nuclear techniques in health by many ways, including obtaining inputs from member states and professional societies. In 2012, a Technical Meeting on trends in hybrid imaging was organized by IAEA to understand the current status and trends of hybrid imaging using nuclear techniques, its role in clinical practice, and associated educational needs and challenges. Perspective of scientific societies and professionals from all the regions of the world was obtained. Heterogeneity in value, educational needs, and access was noted and the drivers of this heterogeneity were discussed. This article presents the key points shared during the technical meeting, focusing primarily on SPECT-CT and PET-CT, and shares the action plan for IAEA to deal with heterogeneity as suggested by the participants.

Managing lymphoma with non-FDG radiotracers: current clinical and preclinical applications

Nuclear medicine imaging modalities such as positron emission tomography (PET) and single-photon emission computed tomography (SPECT) have played a prominent role in lymphoma management. PET with [(18)F]Fluoro-2-deoxy-D-glucose (FDG) is the most commonly used tool for lymphoma imaging. However, FDG-PET has several limitations that give the false positive or false negative diagnosis of lymphoma. Therefore, development of new radiotracers with higher sensitivity, specificity, and different uptake mechanism is in great demand in the management of lymphoma. This paper reviews non-FDG radiopharmaceuticals that have been applied for PET and SPECT imaging in patients with different types of lymphoma, with attention to diagnosis, staging, therapy response assessment, and surveillance for disease relapse. In addition, we introduce three radiolabeled anti-CD20 antibodies for radioimmunotherapy, which is another important arm for lymphoma treatment and management. Finally, the relatively promising radiotracers that are currently under preclinical development are also discussed in this paper.

The impact of coaxial core biopsy guided by FDG PET/CT in oncological patients

OBJECTIVE

When deciding on therapy, FDG PET/CT-positive results should be confirmed by histology if possible. We evaluated the impact of percutaneous PET/CT-guided biopsies on histological confirmation of PET/CT-positive lesions.

METHODS

We prospectively evaluated 126 patients who had undergone a PET/CT scan with positive results with an indication for histological evaluation of lesions. Imaging was performed in a PET/CT scanner with a fluoroscopic imaging system. A total of 130 lesions were accessed by PET/CT-guided biopsy. The technical feasibility, clinical success and complication rates of PET/CT-guided biopsies were evaluated.

RESULTS

Of 130 PET/CT-positive lesions, 128 (98.5 %) were successfully accessed and representative tissue samples obtained. Two lesions were reaccessed due to inconclusive histological results. Histology showed that 99 of the 130 lesions (76.2 %) were malignant, and 31 lesions (23.8 %) were benign (inflammatory cells or necrotic tissue); these patients had no recurrence of disease after a minimum follow-up of 6 months. Also, in 23 of the 130 lesions (17.7 %), the patient was referred for the PET/CT-guided biopsy due to a previous nontumoral biopsy result, and of these 23 lesions, 21 were found to be malignant. The complication rates were: pneumothorax in 15/130 (11.5 %; resolved spontaneously), haemoptysis in 2/130 (1.5 %) and severe haemothorax in 1/130 (0.8 %); there was no procedure-related mortality.

CONCLUSION

PET/CT-guided biopsy is feasible and may optimize the diagnostic yield of image-guided interventions. Also, PET/CT-positive lesions with no morphological correlation may now be accessible to percutaneous interventions.

Hodgkin's lymphoma in adults

Management of Hodgkin's lymphoma continues to develop. Outcomes for patients with favourable-risk, early-stage disease are excellent, and serial reductions in intensity of treatment have been made to retain the excellent prognosis while reducing the late effects of treatment. Prognosis is also very good in advanced-stage disease but the rate of relapse is higher than in early-stage disease, and the optimum first-line treatment is unclear. Workers are investigating the role of functional imaging to assess whether treatment can be tailored according to response, with the most intensive therapies reserved for patients predicted to have poor outcomes. In this Seminar we critically appraise the management of Hodgkin's lymphoma in early-stage disease, advanced-stage disease, and at relapse, with a focus on late effects of treatment.