Is there any maximum standardized uptake value variation among positron emission tomography scanners for mediastinal staging in non-small cell lung cancer?

Abstract

The maximum standardized uptake value (SUV(max)) varies among positron emission tomography-integrated computed tomography (PET/CT) centers in the staging of non-small cell lung cancer. We evaluated the ratio of the optimum SUV(max) cut-off for the lymph nodes to the median SUV(max) of the primary tumor (ratioSUV(max)) to determine SUV(max) variations between PET/CT scanners. The previously described PET predictive ratio (PPR) was also evaluated. PET/CT and mediastinoscopy and/or thoracotomy were performed on 337 consecutive patients between September 2005 and March 2009. Thirty-six patients were excluded from the study. The pathological results were correlated with the PET/CT findings. Histopathological examination was performed on 1136 N2 lymph nodes using 10 different PET/CT centers. The majority of patients (group A: 240) used the same PET/CT scanner at four different centers. Others patients were categorized as group B. The ratioSUV(max) for groups A and B was 0.18 and 0.22, respectively. The same ratio for centers 1, 2, 3 and 4 was 0.2, 0.21, 0.21, and 0.23, respectively. The optimal cut-off value of the PPR to predict mediastinal lymph node pathology for malignancy was 0.49 (likelihood ratio +2.02; sensitivity 70%, specificity 65%). We conclude that the ratioSUV(max) was similar for different scanners. Thus, SUV(max) is a valuable cut-off for comparing-centers.

Ratio of Lymph Node to Primary Tumor SUV on PET/CT Accurately Predicts Nodal Malignancy in Non–Small-Cell Lung Cancer

“…24 This data was largely replicated by Iskender et al, who found in a series of 129 patients with 223 PET-positive lymph nodes that a cutoff value of 0.49 was optimal (sensitivity 70%, specificity 65%). 25 Interestingly, their optimal cutoff values were somewhat higher than the cutoff of 0.28 found in M A N U S C R I P T A C C E P T E D ACCEPTED MANUSCRIPT 13 our study, most likely due to differences in the population of patients studied. For instance, our study was more exclusive in patient selection in order to reduce the rate of false positives from granulomatous disease or other forms of malignancy.…”

“…Indeed, it has been shown that while absolute SUV measurements can vary by 15-20% between centers, [11][12][13][14]36 the SUV ratio is relatively insensitive to the PET protocol used. [24][25] This is actually one of the main advantages to using an SUV ratio, as considerable variation in PET/CT methodology is common in both the United States and internationally even among academic medical centers. [37][38] Our data is strengthened by the fact that 77% of scans were done at our center, but by including scans from other centers our findings are likely to be more generalizable to the realities of clinical practice.…”

Ratio of lymph node to primary tumor SUVmax multiplied by maximal tumor diameter on positron emission tomography/integrated computed tomography may be a predictor of mediastinal lymph node malignancy in lung cancer

“…The AUC of SUV n/t (referred to as PET predictive ratio) was 0.69 with an optimal cut-off of 0.49 for predicting malignancy (sensitivity 70%, specificity 65%). [12] However, the diagnostic utility of LN SUV max was assessed, with an optimal cutoff value 2.75 for predicting malignancy (sensitivity 84%, specificity 87%), whereas the AUC of SUV max was not mentioned or compared with the PET predictive ratio. LN SUV max was shown to be more accurate than SUV n/t for predicting LN malignancy.…”

FDG-PET parameters predicting mediastinal malignancy in lung cancer

“…Standard uptake values of examined regions were assigned by the software of the equipment used in each hospital. To quantify the maximal metabolic activity of lymph nodes in the mediastinum their highest SUVmax was measured, as an absolute value, as a ratio between this value and the SUVmax of the primary tumor, and after the subtraction of this second value from this highest SUVmax in the mediastinum [13–15]. Homogeneity of FDG-PET between hospitals was assessed through comparisons of the SUVmax values of primary lung tumors and of lymph node regions with the highest SUVmax in the mediastinum, both as absolute and as relative values.…”

“…The extensive use of these cutoffs, however, is limited by the variability in the SUVmax values recorded at different FDG-PET centers, which is reported to range between 10% and 15% [11, 12]. The use of ratios between SUVmax values in the mediastinum and the tumor has been proposed as a way of homogenizing the results obtained at different centers and allows the definition of cutoffs that may not be influenced by intercenter variability [13–15]. …”