Quantitative evaluation of skeletal tumours with dynamic FDG PET: SUV in comparison to Patlak analysis

Abstract

This study was carried out to evaluate bone lesions using fluorine-18 fluorodeoxyglucose positron emission tomography (FDG PET) and to explore whether dynamic and quantitative PET data may help to differentiate benign lesions from malignant masses. Forty patients with primary bone lesions were studied. The final diagnosis was confirmed by histopathology. A 60-min dynamic FDG PET acquisition was undertaken in all subjects. From the dynamic PET images, indices such as the average and maximal standardised uptake values (SUVs), the tumour SUV-to-muscle SUV ratio (T/M) and the SUV at 60 min-to-SUV at 30 min ratio (averSUV60/30 min and maxSUV60/30 min) were produced. Patlak graphical analysis was used to obtain the influx constant (Ki), and the metabolic rate of FDG (MRFDG) was calculated. Based on the receiver operator characteristic curve, the sensitivity and specificity for each parameter in differentiating between malignant and benign lesions were evaluated. The histological results revealed 21 malignant tumours and 19 benign lesions in this group. The MRFDG and SUV indices in malignant lesions were significantly higher than those in benign lesions. However, each index showed a considerable overlap between benign and malignant lesions. Average SUV correlated positively with MRFDG (r=0.67). When a cut-off of 1.8 average SUV was used, the sensitivity and specificity for discrimination of malignancy from benign disease were 85% and 82.4%, respectively. MRFDG showed a similar sensitivity (82.4%) and a better specificity (92.9%). A combination consisting of a cut-off of average SUV (1.8) and averSUV60/30 min (1.1) resulted in an improvement of specificity to 93.3%, with a small reduction in sensitivity (81.3%) as compared with exclusive use of SUV. The results of this study indicate that a detectable difference in glucose metabolism exists between malignant and benign skeletal lesions. The static FDG uptake indices alone may not enable adequate differentiation between benign and malignant lesions. Quantitative dynamic imaging may provide more helpful information, but will not permit a definite diagnosis. The use of uptake indices may represent an alternative and interesting approach to the evaluation of bone lesions.

Comparison of SUV and Patlak slope for monitoring of cancer therapy using serial PET scans

“…Rather it was to assess whether differences between the two methods occur, and to gain insight into the reasons behind those differences. This information would permit a better understanding of recent [12,13] and future data assessing the relative clinical efficacy of the two methods.…”

The clinical efficacy of 18F-FDG-PET/CT in benign and malignant musculoskeletal tumors

“…Molecular imaging with positron emission tomography (PET) is uniquely suited for evaluating metabolic activity in human tumors for 1 3 diagnostic imaging purposes [1]. The glucose analog 2-[ 18 F]fl uoro-2-deoxy-D-glucose (FDG) has proved to be successful as a PET imaging agent in detecting and localizing many types of tumor cells and shows enhanced uptake of 18 F-FDG in malignant tumors relative to benign ones [2,3]. However, there is controversy about the ability of 18 F-FDG-PET to differentiate between malignant and benign musculoskeletal tumors because some benign tumors show as high 18 F-FDG uptake as malignant tumors (false positive) and some malignant tumors show low uptake (false negative) [4][5][6].…”

A study of non-invasive Patlak quantification for whole-body dynamic FDG-PET studies of mice

“…Thus, a range of t > 3 min was used in the nPGA method presented in this paper. The PGA method is often compared with the use of the standard uptake value (SUV), a popular semi-quantitative index for the analysis of PET images in cancer diagnosis [26,27]. A comparison between the SUV and nPGA methods will be investigated in the future studies as well as the investigation in non-invasive tumor quantification of human by using nPGA method.…”