PET/CT for the staging and follow-up of patients with malignancies

https://doi.org/10.1016/j.ejrad.2009.03.051Get rights and content

Abstract

Positron emission tomography (PET) and computed tomography (CT) complement each other's strengths in integrated PET/CT. PET is a highly sensitive modality to depict the whole-body distribution of positron-emitting biomarkers indicating tumour metabolic activity. However, conventional PET imaging is lacking detailed anatomical information to precisely localise pathologic findings. CT imaging can readily provide the required morphological data. Thus, integrated PET/CT represents an efficient tool for whole-body staging and functional assessment within one examination. Due to developments in system technology PET/CT devices are continually gaining spatial resolution and imaging speed. Whole-body imaging from the head to the upper thighs is accomplished in less than 20 min. Spatial resolution approaches 2–4 mm. Most PET/CT studies in oncology are performed with 18F-labelled fluoro-deoxy-d-glucose (FDG). FDG is a glucose analogue that is taken up and trapped within viable cells. An increased glycolytic activity is a characteristic in many types of cancers resulting in avid accumulation of FDG. These tumours excel as “hot spots” in FDG-PET/CT imaging. FDG-PET/CT proved to be of high diagnostic value in staging and restaging of different malignant diseases, such as colorectal cancer, lung cancer, breast cancer, head and neck cancer, malignant lymphomas, and many more. The standard whole-body coverage simplifies staging and speeds up decision processes to determine appropriate therapeutic strategies. Further development and implementation of new PET-tracers in clinical routine will continually increase the number of PET/CT indications. This promotes PET/CT as the imaging modality of choice for working-up of the most common tumour entities as well as some of the rare malignancies.

Introduction

In patients with suspected malignancies both prognosis and therapeutic management particularly depend on the tumour stage. Thus, accurate tumour staging preferably encompassing the entire body is of high importance.

PET is a very sensitive modality to depict the spatial whole-body distribution of positron-emitting biomarkers that indicate molecular processes underlying tumour metabolic activity [1]. The average F-18-FDG PET sensitivity and specificity across all indications in oncology are estimated at 84% (based on 18,402 patient studies) and 88% (based on 14,264 patient studies), respectively, according to Gambhir et al. [2] from a collection of 419 articles from 1993 to 2000.

However, sole PET images are lacking detailed anatomical information. Reliable localisation of a lesion within a segment of an organ or even within a certain organ itself can be challenging. Thus, conventional stand-alone PET has mostly been replaced by PET/CT. PET/CT combines the complementary information of functional PET and morphological CT images in one imaging session for improved patient comfort, patient throughput, and most importantly the gain in diagnostic accuracy. FDG-PET/CT has been found superior to both imaging procedures acquired separately in tumour staging and restaging of different malignant diseases [3], [4], [5]. Furthermore, PET/CT potentially supports volume delineation in radiation therapy planning [6]. This may be particularly useful in the head and neck region where a multitude of sensitive structures is confined to a small area of the body. The close vicinity necessitates optimised definition of the treatment volume to minimise the risk of treatment-related toxicities. Another indication for PET/CT in radiation therapy planning is lung tumours where separation of viable tumour from atelectasis can be challenging with morphology alone [6].

While PET imaging has been available since 1980, PET/CT has first been introduced into clinical routine in 2001. Thus, there are many data on PET in oncological applications available in the literature, while data on PET/CT are still limited for some tumour entities. However, depending on the indication and the radionuclide in question data on PET imaging may in all likelihood also apply to PET/CT.

This review will (1) cover methodological issues in PET/CT and (2) focus on the main oncological indications of FDG-PET/CT.

Section snippets

Methodological and technical issues in PET/CT

Two separate scanners, a PET and a CT scanner, are installed in series with a single gantry and examination table serving both imaging devices. Prior to the examination a positron-emitting biomarker is administered. The examination is then performed by positioning the patient on the examination table followed by sequential acquisition of the CT and of the PET images. Both data sets can be combined into a single superposed (coregistered) image. Differences between PET/CT systems apply to the

General clinical issues in oncological FDG-PET/CT

The initiation of a stage-adapted therapy is known to improve outcome in various malignancies [21], [22]. In recent years, numerous studies have evaluated the use of FDG-PET for staging and restaging of tumour patients. The currently available data indicate that PET/CT is more accurate than either of its imaging components alone or if images are acquired with separate PET and CT systems and viewed side by side. PET and CT complement one another in fused PET/CT data sets. PET may be more

Concluding remarks and future perspectives

PET and CT complement each other's strengths in integrated PET/CT. Due to developments in system technology PET/CT devices are continually gaining spatial resolution and imaging speed. The standard whole-body imaging simplifies tumour staging and speeds up decision processes to determine appropriate therapeutic strategies. PET/CT proved to be of high value as the primary staging and restaging modality in many tumour entities. As PET/CT will be useful in all indications where PET proved to be

References (83)

  • G. Antoch et al.

    Whole-body dual-modality PET/CT and whole-body MRI for tumor staging in oncology

    JAMA

    (2003)
  • R. Bar-Shalom et al.

    Clinical performance of PET/CT in evaluation of cancer: additional value for diagnostic imaging and patient management

    J Nucl Med

    (2003)
  • D. Lardinois et al.

    Staging of non-small-cell lung cancer with integrated positron-emission tomography and computed tomography

    N Engl J Med

    (2003)
  • D.E. Heron et al.

    PET–CT in radiation oncology: the impact on diagnosis, treatment planning, and assessment of treatment response

    Am J Clin Oncol

    (2008)
  • G.K. Von Schulthess et al.

    Integrated PET/CT: current applications and future directions

    Radiology

    (2006)
  • M. Farsad et al.

    Detection and localization of prostate cancer: correlation of (11)C-choline PET/CT with histopathologic step-section analysis

    J Nucl Med

    (2005)
  • M. Hofmann et al.

    Biokinetics and imaging with the somatostatin receptor PET radioligand (68)Ga-DOTATOC: preliminary data

    Eur J Nucl Med

    (2001)
  • L.S. Freudenberg et al.

    Value of (124)I-PET/CT in staging of patients with differentiated thyroid cancer

    Eur Radiol

    (2004)
  • G. Brix et al.

    Radiation exposure of patients undergoing whole-body dual-modality 18F-FDG PET/CT examinations

    J Nucl Med

    (2005)
  • T. Beyer et al.

    Dual-modality PET/CT imaging: the effect of respiratory motion on combined image quality in clinical oncology

    Eur J Nucl Med Mol Imaging

    (2003)
  • G.W. Goerres et al.

    Accuracy of image coregistration of pulmonary lesions in patients with non-small cell lung cancer using an integrated PET/CT system

    J Nucl Med

    (2002)
  • S.A. Nehmeh et al.

    Four-dimensional (4D) PET/CT imaging of the thorax

    Med Phys

    (2004)
  • G. Antoch et al.

    To enhance or not to enhance? 18F-FDG and CT contrast agents in dual-modality 18F-FDG PET/CT

    J Nucl Med

    (2004)
  • G. Antoch et al.

    Focal tracer uptake: a potential artifact in contrast-enhanced dual-modality PET/CT scans

    J Nucl Med

    (2002)
  • G.W. Goerres et al.

    Head and neck imaging with PET and PET/CT: artefacts from dental metallic implants

    Eur J Nucl Med Mol Imaging

    (2002)
  • B.S. Halpern et al.

    Cardiac pacemakers and central venous lines can induce focal artifacts on CT-corrected PET images

    J Nucl Med

    (2004)
  • Y. Nakamoto et al.

    Effects of nonionic intravenous contrast agents at PET/CT imaging: phantom and canine studies

    Radiology

    (2003)
  • G. Antoch et al.

    Dual-modality PET/CT scanning with negative oral contrast agent to avoid artifacts: introduction and evaluation

    Radiology

    (2004)
  • A. Forastiere et al.

    Head and neck cancer

    N Engl J Med

    (2001)
  • W.R. Smythe

    Treatment of stage I and II non-small-cell lung cancer

    Cancer Control

    (2001)
  • G. Antoch et al.

    Accuracy of whole-body dual-modality fluorine-18-2-fluoro-2-deoxy-d-glucose positron emission tomography and computed tomography (FDG-PET/CT) for tumor staging in solid tumors: comparison with CT and PET

    J Clin Oncol

    (2004)
  • S.M. Eschmann et al.

    Kopf-Hals-Tumoren

  • D.I. Kutler et al.

    The current status of positron-emission tomography scanning in the evaluation and follow-up of patients with head and neck cancer

    Curr Opin Otolaryngol Head Neck Surg

    (2006)
  • P. Veit-Haibach et al.

    TNM staging with FDG-PET/CT in patients with primary head and neck cancer

    Eur J Nucl Med Mol Imaging

    (2007)
  • A.J. Fleming et al.

    Impact of [18F]-2-fluorodeoxyglucose-positron emission tomography/computed tomography on previously untreated head and neck cancer patients

    Laryngoscope

    (2007)
  • Ferda J, Ferdova E, Zahlava J, et al., (18)F-FDG-PET/CT of orofacial tumors, a value of whole-body imaging approach....
  • S.C. Ong et al.

    Clinical utility of 18F-FDG PET/CT in assessing the neck after concurrent chemoradiotherapy for locoregional advanced head and neck cancer

    J Nucl Med

    (2008)
  • R. Abgral et al.

    Does 18F-FDG PET/CT improve the detection of posttreatment recurrence of head and neck squamous cell carcinoma in patients negative for disease on clinical follow-up?

    J Nucl Med

    (2009)
  • A. Jemal et al.

    Cancer statistics, 2006

    CA Cancer J Clin

    (2006)
  • N. Avril et al.

    Breast imaging with positron emission tomography and fluorine-18 fluorodeoxyglucose: use and limitations

    J Clin Oncol

    (2000)
  • F. Crippa et al.

    Prospective evaluation of fluorine-18-FDG PET in presurgical staging of the axilla in breast cancer

    J Nucl Med

    (1998)
  • Cited by (162)

    • Deep neural network for automatic volumetric segmentation of whole-body CT images for body composition assessment

      2021, Clinical Nutrition
      Citation Excerpt :

      If volumetric CT analysis of body composition could be applied to whole-body CT images, it would be possible to assess sarcopenia and visceral obesity on CT images beyond the L3 level (i.e., chest CT) without additional radiation exposure. Particularly, as 18F-fluorodeoxyglucose PET/CT scan is a vital examination for the surveillance of systematic metastasis in cancer patients and covers the whole body [13,14], the volumetric body composition analysis could enable an assessment of whole-body composition at baseline and during follow-up in cancer patients [15,16]. In this study, we aimed to develop and validate a deep neural network for the volumetric segmentation of body composition applicable to whole-body CT images of PET-CT scan.

    • Research on the midterm efficacy and prognosis of patients with diffuse large B-cell lymphoma by different evaluation methods in interim PET/CT

      2020, European Journal of Radiology
      Citation Excerpt :

      The combination provides accurate information about the anatomy and function of the target organ [6]. The most commonly used imaging agent for conventional imaging is 18-Fluoro-Fluorodeoxyglucose (18F-FDG) [7]. 18F-FDG PET/CT, as a commonly used imaging evaluation method in the diagnosis and judgment of DLBCL, has been widely used in staging, efficacy monitoring and prognosis evaluation [8–10].

    View all citing articles on Scopus
    View full text