Recurrent thyroid cancer diagnosis: ROC study of the effect of a high-resolution head and neck 18F-FDG PET/CT scan

Sofia N Chatziioannou; Alexandros T Georgakopoulos; Nikoletta K Pianou; Georgia Th Kafiri; Spyros N Pavlou; Maria Kallergi

doi:10.1016/j.acra.2013.09.017

Recurrent thyroid cancer diagnosis: ROC study of the effect of a high-resolution head and neck 18F-FDG PET/CT scan

Acad Radiol. 2014 Jan;21(1):58-63. doi: 10.1016/j.acra.2013.09.017.

Authors

Sofia N Chatziioannou¹, Alexandros T Georgakopoulos², Nikoletta K Pianou², Georgia Th Kafiri³, Spyros N Pavlou³, Maria Kallergi⁴

Affiliations

¹ Nuclear Medicine Division, Biomedical Research Foundation of the Academy of Athens, Athens, Greece; 2nd Department of Radiology, Nuclear Medicine Section, University General Hospital Attikon, School of Medicine, National and Kapodistrian University of Athens, Chaidari, Greece.
² Nuclear Medicine Division, Biomedical Research Foundation of the Academy of Athens, Athens, Greece.
³ Endocrine Clinics, Athens, Greece.
⁴ Department of Medical Instruments Technology, Technological Educational Institute of Athens, Egaleo 12210, Greece. Electronic address: sofiac@bcm.edu.

PMID: 24331265
DOI: 10.1016/j.acra.2013.09.017

Abstract

Rationale and objectives: (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) has demonstrated significant value in the evaluation of patients with indication of recurrent thyroid cancer with negative conventional workup. The hypothesis of this study was that the addition of a dedicated, high-resolution head and neck scan (HNS) to the standard whole-body scan (WBS) improves the accuracy of the detection and diagnosis of recurrent thyroid cancer.

Materials and methods: Forty-three consecutive patients suspected for recurrent thyroid cancer, as indicated by increased tumor markers, prospectively underwent a WBS and a HNS with (18)F-FDG PET/CT. The patients were followed up to establish ground truth. A receiver operator characteristic (ROC) study with two observers was conducted to evaluate the impact of the additional HNS on the detection and diagnosis of recurrent thyroid cancer. Indices of performance included the area under the ROC curve (AUC), the number of detected abnormal foci, and the size of the detected foci without and with the HNS images.

Results: ROC results showed that the addition of the HNS to the standard WBS increased the average AUC index of performance from 0.69 to 0.96, a statistically significant difference with a confidence interval (CI) of -0.33 to -0.19. Diagnosis was also improved with the average AUC increasing from 0.79 to 0.87 but differences were not statistically significant (CI, -0.19 to 0.04). Interreader agreement was "good" in the detection task and "excellent" in the diagnostic task. The addition of the HNS increased the number of detected foci in the positive patients by an average of 37%, whereas false-positive detections in the negative patients increased by an average of 10%. Reported average maximum lesion size also increased with the HNS addition by an average of 11%.

Conclusions: The addition of a high-resolution HNS to the standard whole-body PET/CT imaging improves readers' performance in the detection and diagnosis of recurrent thyroid cancer and could greatly benefit patient care.

Keywords: FDG; PET/CT, ROC; Thyroid cancer; positron emission tomography.

MeSH terms

Female
Fluorodeoxyglucose F18*
Humans
Male
Middle Aged
Multimodal Imaging / methods
Neoplasm Recurrence, Local / diagnosis*
Observer Variation
Positron-Emission Tomography / methods*
ROC Curve*
Radiopharmaceuticals
Reproducibility of Results
Sensitivity and Specificity
Thyroid Neoplasms / diagnosis*
Tomography, X-Ray Computed / methods*

Substances

Radiopharmaceuticals
Fluorodeoxyglucose F18