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

Carotid artery molecular calcification assessed by [18F]fluoride PET/CT: correlation with cardiovascular and thromboembolic risk factors

OBJECTIVES

There is growing evidence that sodium fluoride ([¹⁸F]fluoride) PET/CT can detect active arterial calcifications at the molecular stage. We investigated the relationship between arterial mineralization in the left common carotid artery (LCC) assessed by [¹⁸F]fluoride PET/CT and cardiovascular/thromboembolic risk.

METHODS

In total, 128 subjects (mean age 48 ± 14 years, 51% males) were included. [¹⁸F]fluoride uptake in the LCC was quantitatively assessed by measuring the blood-pool-corrected maximum standardized uptake value (SUVmax) on each axial slice. Average SUVmax (aSUVmax) was calculated over all slices and correlated with 10-year risk of cardiovascular events estimated by the Framingham model, CHA2DS2-VASc score, and level of physical activity (LPA).

RESULTS

The aSUVmax was significantly higher in patients with increased risk of cardiovascular (one-way ANOVA, p < 0.01) and thromboembolic (one-way ANOVA, p < 0.01) events, and it was significantly lower in patients with greater LPA (one-way ANOVA, p = 0.02). On multivariable linear regression analysis, age ( = 0.07, 95% CI 0.05 - 0.10, p < 0.01), body mass index ( = 0.02, 95% CI 0.01 - 0.03, p < 0.01), arterial hypertension ( = 0.15, 95% CI 0.08 - 0.23, p < 0.01), and LPA ( = -0.10, 95% CI -0.19 to -0.02, p=0.02) were independent associations of aSUVmax.

CONCLUSIONS

Carotid [¹⁸F]fluoride uptake is significantly increased in patients with unfavorable cardiovascular and thromboembolic risk profiles. [¹⁸F]fluoride PET/CT could become a valuable tool to estimate subjects' risk of future cardiovascular events although still major trials are needed to further evaluate the associations found in this study and their potential clinical usefulness.

KEY POINTS

• Sodium fluoride ([¹⁸F]fluoride) PET/CT imaging identifies patients with early-stage atherosclerosis. • Carotid [¹⁸F]fluoride uptake is significantly higher in patients with increased risk of cardiovascular and thromboembolic events and inversely correlated with the level of physical activity. • Early detection of arterial mineralization at a molecular level could help guide clinical decisions in the context of cardiovascular risk assessment.

Global costs, health benefits, and economic benefits of scaling up treatment and imaging modalities for survival of 11 cancers: a simulation-based analysis

BACKGROUND

In addition to increased availability of treatment modalities, advanced imaging modalities are increasingly recommended to improve global cancer care. However, estimates of the costs and benefits of investments to improve cancer survival are scarce, especially for low-income and middle-income countries (LMICs). In this analysis, we aimed to estimate the costs and lifetime health and economic benefits of scaling up imaging and treatment modality packages on cancer survival, both globally and by country income group.

METHODS

Using a previously developed model of global cancer survival, we estimated stage-specific cancer survival and life-years gained (accounting for competing mortality) in 200 countries and territories for patients diagnosed with one of 11 cancers (oesophagus, stomach, colon, rectum, anus, liver, pancreas, lung, breast, cervix uteri, and prostate) representing 60% of all cancer diagnoses between 2020 and 2030 (inclusive of full years). We evaluated the costs and health and economic benefits of scaling up packages of treatment (chemotherapy, surgery, radiotherapy, and targeted therapy), imaging modalities (ultrasound, x-ray, CT, MRI, PET, single-photon emission CT), and quality of care to the mean level of high-income countries, separately and in combination, compared with no scale-up. Costs and benefits are presented in 2018 US$ and discounted at 3% annually.

FINDINGS

For the 11 cancers studied, we estimated that without scale-up (ie, with current availability of treatment, imaging, and quality of care) there will be 76·0 million cancer deaths (95% UI 73·9-78·6) globally for patients diagnosed between 2020 and 2030, with more than 70% of these deaths occurring in LMICs. Comprehensive scale-up of treatment, imaging, and quality of care could avert 12·5% (95% UI 9·0-16·3) of these deaths globally, ranging from 2·8% (1·8-4·3) in high-income countries to 38·2% (32·6-44·5) in low-income countries. Globally, we estimate that comprehensive scale-up would cost an additional $232·9 billion (95% UI 85·9-422·0) between 2020 and 2030 (representing a 6·9% increase in cancer treatment costs), but produce $2·9 trillion (1·8-4·0) in lifetime economic benefits, yielding a return of $12·43 (6·47-33·23) per dollar invested. Scaling up treatment and quality of care without imaging would yield a return of $6·15 (2·66-16·71) per dollar invested and avert 7·0% (3·9-10·3) of cancer deaths worldwide.

INTERPRETATION

Simultaneous investment in cancer treatment, imaging, and quality of care could yield substantial health and economic benefits, especially in LMICs. These results provide a compelling rationale for the value of investing in the global scale-up of cancer care.

FUNDING

Harvard TH Chan School of Public Health and National Cancer Institute.

Addressing Global Inequities in Positron Emission Tomography-Computed Tomography (PET-CT) for Cancer Management: A Statistical Model to Guide Strategic Planning

Background

According to the World Health Organization (WHO), non-communicable diseases are responsible for 71% of annual global mortality. National governments and international organizations are increasingly considering medical imaging and nuclear medicine access data in strategies to address epidemiologic priorities. Our objective here was to develop a statistical model to assist countries in estimating their needs for PET-CT systems for the management of specific cancer types.

Material/Methods

We introduce a patient-centered statistical model based on country-specific epidemiological data, PET-CT performance, and evidence-based clinical guidelines for PET-CT use for cancer. The output of the model was integrated into a Bayesian model to rank countries or world regions that would benefit the most from upscaling PET-CT scanners.

Results

We applied our model to the IMAGINE database, recently developed by the International Atomic Energy Agency (IAEA). Our model indicates that at least 96 countries should upscale their PET-CT services and more than 200 additional PET-CT scanners would be required to fulfill their needs. The model also provides quantitative evidence indicating that low-income countries would benefit the most from increasing PET-CT provision. Finally, we discuss several cases in which the standard unit [number of scanners]/[million inhabitants] to guide strategic planning or address inequities is misleading.

Conclusions

Our model may help in the accurate delineation and further reduction of global inequities in access to PET-CT scanners. As a template, the model also has the potential to estimate the costs and socioeconomic impact of implementing any medical imaging modality for any clinical application.

FDG-PET/CT Versus Contrast-Enhanced CT for Response Evaluation in Metastatic Breast Cancer: A Systematic Review

18F-fluorodeoxyglucose positron emission tomography with integrated computed tomography (FDG-PET/CT) and contrast-enhanced computed tomography (CT) can be used for response evaluation in metastatic breast cancer (MBC). In this study, we aimed to review literature comparing the PET Response Criteria in Solid Tumors (PERCIST) with Response Evaluation Criteria in Solid Tumors (RECIST) in patients with MBC. We made a systematic search in Embase, PubMed/Medline, and Cochrane Library using a modified PICO model. The population was MBC patients and the intervention was PERCIST or RECIST. Quality assessment was performed using the QUADAS-2 checklist. A total of 1975 articles were identified. After screening by title/abstract, 78 articles were selected for further analysis of which 2 duplicates and 33 abstracts/out of focus articles were excluded. The remaining 43 articles provided useful information, but only one met the inclusion and none of the exclusion criteria. This was a retrospective study of 65 patients with MBC showing one-year progression-free survival for responders versus non-responders to be 59% vs. 27% (p = 0.2) by RECIST compared to 64% vs. 0% (p = 0.0001) by PERCIST. This systematic literature review identified a lack of studies comparing the use of RECIST (with CE-CT) and PERCIST (with FDG-PET/CT) for response evaluation in metastatic breast cancer. The available sparse literature suggests that PERCIST might be more appropriate than RECIST for predicting prognosis in patients with MBC.

Implementation of diagnostic resources for cancer in developing countries: a focus on PET/CT

Positron emission tomography in conjunction with computed tomography (PET/CT) is a relatively novel diagnostic tool which has been proven to be clinically useful in various neoplasms. Currently, only a handful of developing countries have PET/CT capabilities, and in those that do units are mostly located in large urban areas, which limits their availability. The implementation of PET/CT units in low-and-middle income countries is hampered by their high cost, the difficulties associated with their operation, and the limited availability of trained personnel. Furthermore, although the clinical appropriateness of PET/CT is well defined in many scenarios, little is known about its cost-effectiveness, particularly in settings with limited resources. Here, we provide a brief overview of the challenges associated with the implementation of PET/CT in resource-limited settings, including some examples of available data on its cost-effectiveness.

Up-front PET/CT changes treatment intent in patients with head and neck squamous cell carcinoma

PURPOSE

In patients with newly diagnosed head and neck squamous cell carcinoma (HNSCC), we wanted to examine the differences in overall treatment decisions, i.e. curative versus palliative treatment intent, reached by a multidisciplinary team conference (MDTC) based on 18F-fluoro-deoxy-glucose-positron emission tomography/computed tomography (PET/CT) or chest X-ray + MRI of the head and neck (CXR/MRI).

PATIENTS AND METHODS

This was a prospective blinded cohort study based on paired data. Consecutive patients with histologically verified primary HNSCC were invited to participate. All included patients underwent CXR/MRI and PET/CT before diagnostic biopsy. An ordinary MDTC using all available imaging was conducted as per standard practice. After at least 3 months (to eliminate recall bias in the team), the first project MDTC was conducted, based on either CXR/MRI or PET/CT, and the tumor board drew conclusions regarding treatment. After an additional 3 months, a second project MDTC was conducted using the complementary imaging modality.

RESULTS

A total of 307 patients were included. Based on CXR/MRI, 303 patients (99%) were recommended for curative treatment and only four patients (1%) for palliative treatment. Based on PET/CT, the MDTC concluded that 278 (91%) patients were suitable for curative treatment and 29 (9%) patients for palliative treatment. The absolute difference of 8% was statistically significant (95% CI: 4.8%-11.5%, p < 0.001).

CONCLUSIONS

A PET/CT-based imaging strategy significantly changed the decisions regarding treatment intent made by a MDTC for patients diagnosed with HNSCC, when compared with the standard imaging strategy of CXR/MRI.

[18F]Fluorodeoxyglucose (FDG)-Positron Emission Tomography (PET)/Computed Tomography (CT) in Suspected Recurrent Breast Cancer: A Prospective Comparative Study of Dual-Time-Point FDG-PET/CT, Contrast-Enhanced CT, and Bone Scintigraphy

PURPOSE

To prospectively investigate the diagnostic accuracy of [(18)F]fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) with dual-time-point imaging, contrast-enhanced CT (ceCT), and bone scintigraphy (BS) in patients with suspected breast cancer recurrence.

PATIENTS AND METHODS

One hundred women with suspected recurrence of breast cancer underwent 1-hour and 3-hour FDG-PET/CT, ceCT, and BS within approximately 10 days. The study was powered to estimate the precision of the individual imaging tests. Images were visually interpreted using a four-point assessment scale, and readers were blinded to other test results. The reference standard was biopsy along with treatment decisions and clinical follow-up (median, 17 months).

RESULTS

FDG-PET/CT resulted in no false negatives and fewer false positives than the other imaging techniques. Accuracy of results were similar for 1-hour and 3-hour FDG-PET/CT. For distant recurrence, the area under the receiver operating curve was 0.99 (95% CI, 0.97 to 1) for FDG-PET/CT, 0.84 (95% CI, 0.73 to 0.94) for ceCT, and 0.86 (95% CI, 0.77 to 0.94) for the combined ceCT+BS. Of 100 patients, 22 (22%) were verified with distant recurrence, and 18 of these had bone involvement. Nineteen patients (19%) had local recurrence only. In exploratory analyses, diagnostic accuracy of FDG-PET/CT was better than ceCT alone or ceCT combined with BS in diagnosing distant, bone, and local recurrence, shown by a greater area under the receiver operating curve and higher sensitivity, specificity, and superior likelihood ratios.

CONCLUSION

FDG-PET/CT was accurate in diagnosing recurrence in breast cancer patients. It allowed for distant recurrence to be correctly ruled out and resulted in only a small number of false-positive cases. Exploratory findings suggest that FDG-PET/CT has greater accuracy than conventional imaging technologies in this patient group.