Inter-Observer Agreement of Whole-Body Computed Tomography in Staging and Response Assessment in Lymphoma: The Lugano Classification

Abstract

Background: To assess inter-observer agreement of whole-body computed tomography (WBCT) in staging and response assessment in lymphoma according to the Lugano classification.

Material/methods: Retrospective analysis was conducted of 115 consecutive patients with lymphomas (45 females, 70 males; mean age of 46 years). Patients underwent WBCT with a 64 multi-detector CT device for staging and response assessment after a complete course of chemotherapy. Image analysis was performed by 2 reviewers according to the Lugano classification for staging and response assessment.

Results: The overall inter-observer agreement of WBCT in staging of lymphoma was excellent (k=0.90, percent agreement=94.9%). There was an excellent inter-observer agreement for stage I (k=0.93, percent agreement=96.4%), stage II (k=0.90, percent agreement=94.8%), stage III (k=0.89, percent agreement=94.6%) and stage IV (k=0.88, percent agreement=94%). The overall inter-observer agreement in response assessment after a completer course of treatment was excellent (k=0.91, percent agreement=95.8%). There was an excellent inter-observer agreement in progressive disease (k=0.94, percent agreement=97.1%), stable disease (k=0.90, percent agreement=95%), partial response (k=0.96, percent agreement=98.1%) and complete response (k=0.87, Percent agreement=93.3%).

Conclusions: We concluded that WBCT is a reliable and reproducible imaging modality for staging and treatment assessment in lymphoma according to the Lugano classification.

Keywords: Hodgkin Disease; Neoplasm Staging; Response Elements.

Figure 1

Stages of lymphomas: (A) Axial, contrast CT scan of the abdomen shows a single splenic focal lesion (stage I). (B) Axial, contrast CT scan of the chest shows an amalgamated mass of multiple enlarged lymph nodes ipsilateral to the diaphragm (stage II). (C) Coronal WBCT shows enlarged axillary lymph nodes above the diaphragm and splenic focal lesions below the diaphragm (stage III). (D, E) Coronal WBCT shows multifocal hepatic lesions with multiple pulmonary nodules (stage IV).

Figure 2

Complete response: (A) Axial, contrast CT before therapy shows enlarged mediastinal lymph nodes. (B) Axial, contrast CT scan after 4 cycles of chemotherapy shows complete disappearance of the target nodes.

Figure 3

Partial response: (A) Axial CT shows enlarged inguinal lymph nodes. (B) Axial, contrast CT shows a regressive course with decreased sizes of inguinal lymph nodes.

Figure 4

Stable Disease: (A) Axial, contrast CT scan shows focal lesions in the left thyroid lobe. (B) Axial, contrast CT scan after a complete course of chemotherapy shows stable appearance of the left thyroid focal lesion.

Figure 5

Progressive disease: (A) Axial CT scan shows few small focal lesions in the spleen. (B) Axial CT scan after a complete course of chemotherapy shows increased sizes and number of the splenic focal lesions.