Computertomography-Based Prediction of Complete Response Following Neoadjuvant Chemoradiotherapy of Locally Advanced Rectal Cancer

Marina Maslova; Heinz Herden; Karin Schork; Michael Turewicz; Martin Eisenacher; Roland Schroers; Alexander Baraniskin; Thomas Mika

doi:10.3389/fonc.2021.623144

Computertomography-Based Prediction of Complete Response Following Neoadjuvant Chemoradiotherapy of Locally Advanced Rectal Cancer

Front Oncol. 2021 May 31:11:623144. doi: 10.3389/fonc.2021.623144. eCollection 2021.

Authors

Marina Maslova¹, Heinz Herden², Karin Schork³, Michael Turewicz³, Martin Eisenacher³, Roland Schroers⁴, Alexander Baraniskin⁴, Thomas Mika⁴

Affiliations

¹ Department of Radiology, Neuroradiology and Nuclear Medicine, Knappschaftskrankenhaus Bochum, Ruhr University Bochum, Bochum, Germany.
² Department of Radiology, VAMED Clinic, Bad Berleburg, Germany.
³ Medizinisches Proteom-Center, Ruhr University Bochum, Bochum, Germany.
⁴ Department of Medicine, Hematology and Oncology, Knappschaftskrankenhaus Bochum, Ruhr University Bochum, Bochum, Germany.

Abstract

Therapeutic strategies for patients with locally advanced rectal cancer (LARC) who are achieving a pathological complete response (pCR) after neoadjuvant radio-chemotherapy (neoCRT) are being increasingly investigated. Recent trials challenge the current standard therapy of total mesorectal excision (TME). For some patients, the treatment strategy of "watch-and-wait" seems a preferable procedure. The key factor in determining individual treatment strategies following neoCRT is the precise evaluation of the tumor response. Contrast-enhanced computer tomography (ceCT) has proven its ability to discriminate benign and malign lesions in multiple cancers. In this study, we retrospectively analyzed the ceCT based density of LARC in 30 patients, undergoing neoCRT followed by TME. We compared the tumors´ pre- and post-neoCRT density and correlated the results to the amount of residual vital tumor cells in the resected tissue. Overall, the density decreased after neoCRT, with the highest decrease in patients achieving pCR. Densitometry demonstrated a specificity of 88% and sensitivity of 68% in predicting pCR. Thus, we claim that ceCT based densitometry is a useful tool in identifying patients with LARC who may benefit from a "watch-and-wait" strategy and suggest further prospective studies.

Keywords: computer tomography; locally advanced rectal cancer; neoadjuvant chemoradiotherapy; pathologic complete response; predictive mode; watch and wait.