Abstract | PURPOSE: PROCEDURES: SSTR2 expression of the 60 liver metastases in 30 NET patients was assessed at baseline and after PRRT by measuring SUVmax, tumor to spleen ratio (T/S ratio), and tumor to liver ratio (T/L ratio). Based on morphological changes and tumor size measured at baseline and follow-up contrast-enhanced CT (after three cycles of PRRT), lesions were divided into two groups by the following: (i) responding (n = 40) and (ii) non-responding (n = 20). RESULTS: Statistically significant differences were observed in the mean SUVmax for non-responding vs. responding lesions at baseline (18.00 ± 3.59 vs. 33.55 ± 4.62, p < 0.05) and for the mean T/S ratio (1.20 ± 0.37 vs. 1.90 ± 0.45, p < 0.05) and the mean T/L ratio (3.15 ± 0.53 vs. 4.97 ± 0.62, p < 0.05). Using the receiver operating characteristic curves, SUVmax was found a better metric than both T/L ratio and T/S ratio (area under the curve (AUC) of SUVmax 0.87; T/L ratio 0.78; T/S ratio 0.73) as a stratification criterion. Using a threshold value of >16.4 for SUVmax, the sensitivity and specificity in predicting responding lesions were 95 and 60 %, respectively. CONCLUSION: We propose a SUVmax cutoff of >16.4 from [(68)Ga] DOTATOC-PET-CT to select patients for PRRT. A T/L ratio >2.2 might present a scanner-independent criterion that enables the translation of our results to other institutions. However, the robustness of this arbitrary unit still needs to be evaluated with different PET scanners.
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Authors | C Kratochwil, M Stefanova, E Mavriopoulou, T Holland-Letz, A Dimitrakopoulou-Strauss, A Afshar-Oromieh, W Mier, U Haberkorn, F L Giesel |
Journal | Molecular imaging and biology
(Mol Imaging Biol)
Vol. 17
Issue 3
Pg. 313-8
(Jun 2015)
ISSN: 1860-2002 [Electronic] United States |
PMID | 25319765
(Publication Type: Journal Article)
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Chemical References |
- Contrast Media
- Ga(III)-DOTATOC
- Organometallic Compounds
- Peptides
- Radiopharmaceuticals
- Receptors, Somatostatin
- SSTR2 protein, human
- Octreotide
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Topics |
- Aged
- Contrast Media
- Female
- Humans
- Liver Neoplasms
(diagnostic imaging, pathology, secondary)
- Male
- Middle Aged
- Multimodal Imaging
- Neoplasm Metastasis
- Neuroendocrine Tumors
(diagnostic imaging)
- Octreotide
(analogs & derivatives, chemistry)
- Organometallic Compounds
(chemistry)
- Peptides
(chemistry)
- Positron-Emission Tomography
- Probability
- ROC Curve
- Radiopharmaceuticals
(chemistry)
- Receptors, Somatostatin
(chemistry, metabolism)
- Tomography, X-Ray Computed
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