Monitoring of tumor response after induction chemotherapy using contrast-enhanced ultrasound (CEUS)

Introduction:

Chemotherapy of tumors in the head and neck represents an alternative to surgical resection in cases of extensive disease. To date imaging modalities, i.e. CT- and MRI-scans combined with endoscopic examinations, including histopathological examination of specimens, have been used for therapy monitoring. The purpose of this study is to prove whether contrast-enhanced ultrasound (CEUS) is suitable as a monitoring tool during tumor therapy.

Methods:

MRI scans, CEUS assessment and endoscopic examinations with histopathological examination of specimens were performed before and after 2 cycles of chemotherapy for the treatment of oropharyngeal cancer. The tumor size was measured as volumetric calculation of the MRI scans. CEUS was analyzed qualitatively and quantitatively by using time-intensity curves and determination of the area under the curve (AUC).

Results:

The calculation of tumor mass in the MRI scans revealed a decrease of about 80% after 2 cycles of chemotherapy. The endoscopic examination also showed a complete remission of tumor. Histopathologically no vital tumor cells were confirmed. CEUS assessment of the tumor site showed no detectable signs of residual perfusion of the former tumor area in the qualitative analysis. The AUC decreased from 261 [dB x s] to 101 [dB x s].

Conclusions:

By application of CEUS, the therapeutic effect of chemotherapy could be shown qualitatively and quantitatively. So it is reasonable to conclude that CEUS is suitable as a non-invasive tool in the ENT-specialist's hand to monitor tumor therapy. In addition to the morphologic analysis of tumor size by imaging techniques (i.e. CT and MRI), CEUS allows a more detailed functional examination of the tumor's vitality by perfusion analysis.

Publication History

Publication Date:
18 April 2018 (online)