Benefit of PET or PET/CT in bone and soft tissue tumors is not proven

March 06, 2013

For patients with bone and soft tissue tumours, the study data currently available allow no robust conclusions as to the advantages and disadvantages of using positron emission tomography (PET), alone or in combination with computed tomography (CT). This is because no studies have directly compared the benefit of these imaging techniques with conventional diagnostics. And the few available studies on diagnostic accuracy do not show any relevant differences. This is the conclusion of the final report of the German Institute for Quality and Efficiency in Health Care (IQWiG) published on 15th February 2013.

More reliable diagnosis ought to improve treatment

Bone and soft tissue tumours are rare diseases of the musculoskeletal system and soft tissue. Malignant types are particularly rare; they only represent a relatively small proportion of all cancers. Soft tissue tumours arise from different types of connective tissue, e.g. fibrous or fat tissue. They are responsible for about one per cent of cancer deaths in Germany each year. The proportion of bone tumours is lower.

Many experts hope that an examination using PET or PET/CT alone or in combination with other methods is better able to distinguish between benign and malignant tumours (primary diagnostics). PET is used to help classify the stage of the tumours correctly (primary staging) and better assess whether they respond to therapy (restaging). Experts also hope that PET or PET/CT helps them find out earlier, and with greater certainty, whether a recurrence has occurred or a secondary tumour (metastasis) has developed. This information should help them give better treatment recommendations to patients.

Benefit for patients crucial

IQWiG therefore searched the international literature for studies that had examined the consequences of a diagnostic intervention using PET or PET/CT on health aspects of direct relevance to patients. For example, the test results - and appropriately tailored treatment - could contribute to better chances of survival for patients, spare them unnecessary treatment or further diagnostic interventions, or improve their quality of life. However, the search for such studies was unsuccessful, so the question as to the patient-relevant benefit of PET or PET/CT in bone and soft tissue tumours had to remain unanswered.

Available studies are very small and susceptible to bias

In addition, IQWiG searched for studies that had assessed the diagnostic and prognostic accuracy, i.e. the accuracy of diagnosis and the power to predict the course of disease, of PET or PET/CT or that had compared PET or PET/CT and other testing methods regarding these criteria. The basic question is how often an investigation gives a correct result. On the one hand, it should overlook true tumours as rarely as possible, but on the other, it should raise false suspicions as rarely as possible.

IQWiG evaluated the results of a total of 32 individual studies on this topic. However, most of these studies only included few participants and were also susceptible to bias, so their results are subject to great uncertainty.

Eight of these studies compared PET or PET/CT with conventional imaging techniques (MRI, X-ray, CT). However, none of these 8 studies found the diagnostic accuracy of PET or PET/CT to be statistically significantly higher than conventional techniques. No prognostic accuracy studies comparing PET or PET/CT with conventional techniques were found.

So the possible benefit of PET or PET/CT in comparison with conventional techniques remains unclear.

Process of report production

IQWiG published the preliminary results in the form of the preliminary report in June 2012 and interested parties were invited to submit comments. At the end of the commenting procedure, which included an oral scientific debate including parties who had submitted comments, the preliminary report was revised and sent as a final report to the contracting agency, the Federal Joint Committee (G-BA), in December 2012. The written comments were published in a separate document at the same time as the final report. The report was produced in collaboration with external experts.

Institute for Quality and Efficiency in Health Care

Related Computed Tomography Articles from Brightsurf:

Prehistoric shark hid its largest teeth
Some, if not all, early sharks that lived 300 to 400 million years ago not only dropped their lower jaws downward but rotated them outwards when opening their mouths.

Dynamic full-field optical coherence tomography: 3D live-imaging of retinal organoids
Optical coherence tomography offers astounding opportunities to image the complex structure of living tissue but lacks functional information.

Cryo-electron tomography reveals uromodulin's role in urinary tract infection protection
Free-flowing filaments of Uromodulin protect against urinary tract infections (UTIs) by duping potentially harmful bacteria to attach to their fishbone-like molecular architecture - rather than to sensitive urinary tract tissues - before being flushed out of the body during urination, researchers report.

Tomography studies of coins shed light on the history of Volga Bulgaria
Kazan Federal University, Joint Institute for Nuclear Research (Dubna, Russia), and Khalikov Institute of Archeology (Tatarstan Academy of Sciences, Kazan, Russia) are working together to study the physical properties of the coins found on the territory of former Volga Bulgaria.

COVID-19 news from Annals of Internal Medicine
In this Ideas and Opinions piece from the University of California, San Francisco and San Francisco Veterans Affairs Medical Center, the authors discuss the findings of early studies that addressed the use of chest computed tomography for the detection of COVID-19.

Scientists pair machine learning with tomography to learn about material interfaces
Researchers have put a new technique based on machine learning to work uncovering the secrets of buried interfaces and edges in a material.

A convex-optimization-based quantum process tomography method for reconstructing quantum channels
Researchers from SJTU have developed a convex-optimization-based quantum process tomography method for reconstructing quantum channels, and have shown the validity to seawater channels and general channels, enabling a more precise and robust estimation of the elements of the process matrix with less demands on preliminary resources.

Faster than ever -- neutron tomography detects water uptake by roots
The high-speed neutron tomography developed at HZB generates a complete 3D image every 1.5 seconds and is thus seven times faster than before.

Staging β-amyloid pathology with amyloid positron emission tomography
This multicenter study used in vivo β-amyloid cerebrospinal fluid, a biomarker of Alzheimer disease, and positron emission tomography findings to track progression of Alzheimer disease over six years among study participants.

NLST follow up reaffirms that low dose CT reduces lung cancer mortality
The authors of the National Lung Cancer Screening Trial report on an extended analysis of the patient cohort that was followed up on after the 2011 study was published.

Read More: Computed Tomography News and Computed Tomography Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to