Dual-Layer Spectral Detector CT in Comparison with FDG-PET/CT for the Assessment of Lymphoma Activity

Abstract

Purpose In patients with malignant lymphoma, disease activity is recommended to be assessed by FDG-PET/CT and the Deauville five-point scale (5-PS). The purpose of this study was to explore the potential of iodine concentration measured in contrast-enhanced dual-layer spectral detector CT (SDCT) as an alternative surrogate parameter for lymphoma disease activity by investigating its correlation with maximum standardized uptake values (SUV_max) and 5-PS.

Materials and Methods 25 patients were retrospectively analyzed. Contrast-enhanced SDCT and FDG-PET/CT were performed in the same treatment interval within at most 3 months. CT attenuation values (AV), absolute iodine concentrations (aIC), and normalized iodine concentrations (nIC) of lymphoma lesions were correlated with SUV_max using Spearman’s rank correlation coefficient. The performance of aIC and nIC to detect lymphoma activity (defined as 5-PS > 3) was determined using ROC curves.

Results 60 lesions were analyzed, and 31 lesions were considered active. AV, aIC, and nIC all correlated significantly with SUV_max. The strongest correlation (Spearman ρ = 0.71; p < 0.001) and highest area under the ROC curve (AUROC) for detecting lymphoma activity were observed for nIC normalized to inferior vena cava enhancement (AUROC = 0.866). The latter provided sensitivity, specificity, and diagnostic accuracy of 87 %, 75 %, and 80 %, respectively, at a threshold of 0.20. ROC analysis for AV (AUROC = 0.834) and aIC (AUROC = 0.853) yielded similar results.

Conclusion In malignant lymphomas, there is a significant correlation between metabolic activity as assessed by FDG-PET/CT and iodine concentration as assessed by SDCT. Iodine concentration shows promising diagnostic performance for detecting lymphoma activity and may represent a potential imaging biomarker.

Key Points: 

• Iodine concentration correlates significantly with SUV_max in lymphoma patients

• Iodine concentration may represent a potential imaging biomarker for detecting lymphoma activity

• Normalization of iodine concentration improves diagnostic performance of iodine concentration

Citation Format

• Gehling K, Mokry T, Do TD et al. Dual-Layer Spectral Detector CT in Comparison with FDG-PET/CT for the Assessment of Lymphoma Activity. Fortschr Röntgenstr 2022; 194: 747 – 754

Zusammenfassung

Ziel Zur Bestimmung der Krankheitsaktivität maligner Lymphome werden das FDG-PET/CT und die Deauville 5-Punkte-Skala (5-PS) empfohlen. Als potenzieller CT-basierter Biomarker für Krankheitsaktivität kann die Jodkonzentration in Lymphomläsionen mit der Dual-Layer Spektraldetektor-CT (SDCT) quantifiziert werden. Ziel dieser Studie war, die Jodkonzentration mit den SUV-Werten (SUV_max) zu korrelieren und die diagnostische Wertigkeit der Jodkonzentration mit der 5-PS als Referenzstandard zu bestimmen.

Material und Methoden 25 Lymphompatienten wurden retrospektiv analysiert. SDCTs in der portalvenösen Phase und FDG-PET/CTs wurden innerhalb von maximal 3 Monaten ohne zwischenzeitlichen Therapiewechsel durchgeführt. Der Zusammenhang zwischen CT-Dichtewerten, absoluten Jodkonzentrationen (aIC) sowie normalisierten Jodkonzentrationen (nIC) und SUV_max wurden mittels Spearman-Rangkorrelationskoeffizienten untersucht. Die Vorhersagekraft von aIC und nIC zur Beurteilung der Lymphomaktivität (5-PS> 3) wurde durch Receiver Operating Characteristics (ROC)-Kurven geprüft.

Ergebnisse Insgesamt wurden 60 Läsionen analysiert und 31 Läsionen gemäß 5-PS als aktiv gewertet. CT-Dichtewerte, aIC and nIC korrelierten signifikant mit SUV_max. Die stärkste Korrelation (Spearman ρ = 0.71; p < 0.001) und der höchste Wert für die Fläche unter der ROC-Kurve (AUROC) zur Detektion von Lymphomaktivität wurde für nIC normalisiert auf die Vena cava inferior beobachtet (AUROC = 0.866). Hierfür ergaben sich eine Sensitivität von 87 %, eine Spezifität von 75 % sowie eine Genauigkeit von 80 % bei einem Schwellenwert von 0.20. ROC-Analysen für die Dichtewerte (AUROC = 0.834) und aIC (AUROC = 0.853) zeigten vergleichbare Ergebnisse.

Schlussfolgerung Die mittels SDCT ermittelte Jodkonzentration korreliert signifikant mit der mittels FDG-PET/CT ermittelten metabolischen Aktivität maligner Lymphome. Die Jodkonzentration zeigt vielversprechende diagnostische Vorhersagekraft zur Detektion von Lymphomaktivität.

Kernaussagen: 

• Die Jodkonzentration maligner Lymphome korreliert signifikant mit SUV-Werten

• Die Jodkonzentration stellt einen potenziellen Biomarker für die Detektion von Lymphomaktivität dar

• Die Normalisierung der Jodkonzentration verbessert die diagnostische Vorhersagekraft

Key words

lymphoma - iodine - PET-CT - fluorine - radioactive - CT

Publication History

Received: 12 September 2021

Accepted: 23 December 2021

Article published online:
24 February 2022

• References

• 1 El-Galaly TC, Gormsen LC, Hutchings M. PET/CT for Staging; Past, Present, and Future. Semin Nucl Med 2018; 48: 4-16 DOI: 10.1053/j.semnuclmed.2017.09.001.
• 2 Barrington SF, Mikhaeel NG, Kostakoglu L. et al. Role of imaging in the staging and response assessment of lymphoma: consensus of the International Conference on Malignant Lymphomas Imaging Working Group. J Clin Oncol 2014; 32: 3048-3058 DOI: 10.1200/JCO.2013.53.5229.
• 3 Cheson BD, Pfistner B, Juweid ME. et al. Revised response criteria for malignant lymphoma. J Clin Oncol 2007; 25: 579-586 DOI: 10.1200/JCO.2006.09.2403.
• 4 Follows GA, Ardeshna KM, Barrington SF. et al. Guidelines for the first line management of classical Hodgkin lymphoma. Br J Haematol 2014; 166: 34-49 DOI: 10.1111/bjh.12878.
• 5 Barrington SF, Mikhaeel NG. When should FDG-PET be used in the modern management of lymphoma?. Br J Haematol 2014; 164: 315-328 DOI: 10.1111/bjh.12601.
• 6 Rutten A, Prokop M. Contrast agents in X-ray computed tomography and its applications in oncology. Anticancer Agents Med Chem 2007; 7: 307-316 DOI: 10.2174/187152007780618162.
• 7 Rassouli N, Etesami M, Dhanantwari A. et al. Detector-based spectral CT with a novel dual-layer technology: principles and applications. Insights Imaging 2017; 8: 589-598 DOI: 10.1007/s13244-017-0571-4.
• 8 Li Q, Li X, Li XY. et al. Spectral CT in Lung Cancer: Usefulness of Iodine Concentration for Evaluation of Tumor Angiogenesis and Prognosis. Am J Roentgenol 2020; 215: 595-602 DOI: 10.2214/ajr.19.22688.
• 9 Luo N, Li W, Xie J. et al. Preoperative normalized iodine concentration derived from spectral CT is correlated with early recurrence of hepatocellular carcinoma after curative resection. Eur Radiol 2020; DOI: 10.1007/s00330-020-07330-6.
• 10 Simons D, Kachelriess M, Schlemmer HP. Recent developments of dual-energy CT in oncology. Eur Radiol 2014; 24: 930-939 DOI: 10.1007/s00330-013-3087-4.
• 11 Cheson BD, Fisher RI, Barrington SF. et al. Recommendations for initial evaluation, staging, and response assessment of Hodgkin and non-Hodgkin lymphoma: the Lugano classification. J Clin Oncol 2014; 32: 3059-3068 DOI: 10.1200/JCO.2013.54.8800.
• 12 Cheson BD, Horning SJ, Coiffier B. et al. Report of an international workshop to standardize response criteria for non-Hodgkinʼs lymphomas. NCI Sponsored International Working Group. J Clin Oncol 1999; 17: 1244 DOI: 10.1200/JCO.1999.17.4.1244.
• 13 Patel BN, Vernuccio F, Meyer M. et al. Dual-Energy CT Material Density Iodine Quantification for Distinguishing Vascular From Nonvascular Renal Lesions: Normalization Reduces Intermanufacturer Threshold Variability. Am J Roentgenol 2019; 212: 366-376 DOI: 10.2214/Am J Roentgenol.18.20115.
• 14 Barrington SF, Kirkwood AA, Franceschetto A. et al. PET-CT for staging and early response: results from the Response-Adapted Therapy in Advanced Hodgkin Lymphoma study. Blood 2016; 127: 1531-1538 DOI: 10.1182/blood-2015-11-679407.
• 15 Flechsig P, Kratochwil C, Schwartz LH. et al. Quantitative volumetric CT-histogram analysis in N-staging of 18F-FDG-equivocal patients with lung cancer. J Nucl Med 2014; 55: 559-564 DOI: 10.2967/jnumed.113.128504.
• 16 Giesel FL, Schneider F, Kratochwil C. et al. Correlation Between SUVmax and CT Radiomic Analysis Using Lymph Node Density in PET/CT-Based Lymph Node Staging. J Nucl Med 2017; 58: 282-287 DOI: 10.2967/jnumed.116.179648.
• 17 Lee JW, Kim EY, Kim DJ. et al. The diagnostic ability of (18)F-FDG PET/CT for mediastinal lymph node staging using (18)F-FDG uptake and volumetric CT histogram analysis in non-small cell lung cancer. Eur Radiol 2016; 26: 4515-4523 DOI: 10.1007/s00330-016-4292-8.
• 18 Flechsig P, Walker C, Kratochwil C. et al. Role of CT Density in PET/CT-Based Assessment of Lymphoma. Mol Imaging Biol 2018; 20: 641-649 DOI: 10.1007/s11307-017-1155-x.
• 19 Hanahan D, Weinberg RA. Hallmarks of cancer: the next generation. Cell 2011; 144: 646-674 DOI: 10.1016/j.cell.2011.02.013.
• 20 Chandarana H, Megibow AJ, Cohen BA. et al. Iodine quantification with dual-energy CT: phantom study and preliminary experience with renal masses. Am J Roentgenol 2011; 196: W693-700 DOI: 10.2214/Am J Roentgenol.10.5541.
• 21 Andersen MB, Ebbesen D, Thygesen J. et al. Impact of spectral body imaging in patients suspected for occult cancer: a prospective study of 503 patients. Eur Radiol 2020; 30: 5539-5550 DOI: 10.1007/s00330-020-06878-7.
• 22 Kessner R, Große Hokamp N, Ciancibello L. et al. Renal cystic lesions characterization using spectral detector CT (SDCT): Added value of spectral results. Br J Radiol 2019; 92: 20180915 DOI: 10.1259/bjr.20180915.
• 23 Ascenti G, Mileto A, Krauss B. et al. Distinguishing enhancing from nonenhancing renal masses with dual-source dual-energy CT: iodine quantification versus standard enhancement measurements. Eur Radiol 2013; 23: 2288-2295 DOI: 10.1007/s00330-013-2811-4.
• 24 Ha T, Kim W, Cha J. et al. Differentiating pulmonary metastasis from benign lung nodules in thyroid cancer patients using dual-energy CT parameters. Eur Radiol 2021; DOI: 10.1007/s00330-021-08278-x.
• 25 Wen Q, Yue Y, Shang J. et al. The application of dual-layer spectral detector computed tomography in solitary pulmonary nodule identification. Quant Imaging Med Surg 2021; 11: 521-532 DOI: 10.21037/qims-20-2.
• 26 Baxa J, Matouskova T, Krakorova G. et al. Dual-Phase Dual-Energy CT in Patients Treated with Erlotinib for Advanced Non-Small Cell Lung Cancer: Possible Benefits of Iodine Quantification in Response Assessment. Eur Radiol 2016; 26: 2828-2836 DOI: 10.1007/s00330-015-4092-6.
• 27 Hellbach K, Sterzik A, Sommer W. et al. Dual energy CT allows for improved characterization of response to antiangiogenic treatment in patients with metastatic renal cell cancer. Eur Radiol 2017; 27: 2532-2537 DOI: 10.1007/s00330-016-4597-7.
• 28 Dai X, Schlemmer HP, Schmidt B. et al. Quantitative therapy response assessment by volumetric iodine-uptake measurement: initial experience in patients with advanced hepatocellular carcinoma treated with sorafenib. Eur J Radiol 2013; 82: 327-334 DOI: 10.1016/j.ejrad.2012.11.013.
• 29 Apfaltrer P, Meyer M, Meier C. et al. Contrast-enhanced dual-energy CT of gastrointestinal stromal tumors: is iodine-related attenuation a potential indicator of tumor response?. Invest Radiol 2012; 47: 65-70 DOI: 10.1097/RLI.0b013e31823003d2.
• 30 Mathy RM, Fritz F, Mayer P. et al. Iodine concentration and tissue attenuation in dual-energy contrast-enhanced CT as a potential quantitative parameter in early detection of local pancreatic carcinoma recurrence after surgical resection. Eur J Radiol 2021; 143: 109944 DOI: 10.1016/j.ejrad.2021.109944.
• 31 Platt JF, Reige KA, Ellis JH. Aortic enhancement during abdominal CT angiography: correlation with test injections, flow rates, and patient demographics. Am J Roentgenol 1999; 172: 53-56 DOI: 10.2214/ajr.172.1.9888738.