Pretherapeutic scan time-normalized tumor to blood standard uptake ratio (SUR) is superior to SUV as a prognostic factor in patients with esophageal carcinoma


Pretherapeutic scan time-normalized tumor to blood standard uptake ratio (SUR) is superior to SUV as a prognostic factor in patients with esophageal carcinoma

Hofheinz, F.; Bütof, R.; Zöphel, K.; Schütze, C.; Löck, S.; Steffen, I. G.; Stadelmann, T.; Kotzerke, J.; Baumann, M.; van den Hoff, J.

Aim: Determination of tumor SUV is widely used for quantitative assessment of tumor metabolism in FDG PET and its potential for therapy outcome prediction in various cancer diseases is under scrutiny. However, the SUV approach has several well known limitations compromising its ability to act as a surrogate parameter of glucose consumption. Recently, we have shown that SUR overcomes most of these limitations as long as FDG kinetics in the target structure can be considered irreversible [1,2]. The aim of this work was to evaluate the prognostic value of SUR in comparison to SUV in patients with esophageal carcinoma.
Methods: FDG-PET/CT was performed in 97 consecutive patients ((64+/-10)y, 83 males) with newly diagnosed esophageal cancer prior to definitive radiochemotherapy. In the PET images the metabolic active volume (MTV) of the primary tumor was delineated with an adaptive threshold method. For determination of the blood SUV the aorta was delineated manually in the attenuation CT. The aorta ROI was transferred to the PET image. Blood SUV was computed as the mean value of the aorta ROI. SUR values were computed as ratio of tumor SUV and blood SUV. SUR values were scan-time-normalized to 60 min p.i. as described in [2]. Univariate Cox regression with respect to overall survival (OS), locoregional control (LRC), and distant-metastases-free survival (DM) was performed for SUVmax, SURmax and clinically relevant parameters. Additionally, a multivariate Cox regression including N stage and smoking status (univariate significant) as confounding parameters was performed.
Results: Both, SUVmax and SURmax, were prognostic factors for OS and DM, but not for LRC. With respect to OS a univariate Cox regression showed a slightly increased hazard ratio (HR) for SURmax (HR=2.3, p=0.001) compared to SUVmax (HR=2.1, p=0.001). With respect to DM HR of SURmax was notably larger than HR of SUVmax (HR=5.7, p=0.005 compared to 3.1, p=0.006). Moreover, in a multivariate Cox regression the prognostic value of SUR was slightly higher for OS and notably higher for DM.
Conclusion: Our results indicate an increased prognostic value if lesion uptake is characterized by time-normalized SUR instead of SUV in pretherapeutic FDG PET of patients with esophageal carcinoma. More comprehensive investigations are necessary to confirm these results.
Literature: [1] van den Hoff et al, EJNMMI Res 2013, 3:77 [2] van den Hoff et al, EJNMMI Res 2014, 4:18

  • Lecture (Conference)
    Annual Congress of the European Association of Nuclear Medicine (EANM), 18.-22.10.2014, Gothenburg, Sweden
  • Abstract in refereed journal
    European Journal of Nuclear Medicine and Molecular Imaging 41(2014), S232-S233
    DOI: 10.1007/s00259-014-2901-9

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Publ.-Id: 21297