2Department of Radiology, Kayseri City Hospital, Kayseri-Turkey
3Department of Genaral Surgery, Kayseri City Hospital, Kayseri-Turkey
4Department of Pathology, Kayseri City Hospital, Kayseri-Turkey
5Department of Medical Oncology, Kayseri City Hospital, Kayseri-Turkey
6Department of Radiation Oncology, Nevsehir State Hospital, Nevsehir-Turkey DOI : 10.5505/tjo.2021.2873 OBJECTIVE
The compatibility between magnetic resonance imaging tumor regression grade (mrTRG) and pathological tumor regression grade (pTRG) was examined in patients with locally advanced rectal cancer (LARC) who underwent neoadjuvant chemoradiotherapy (nCRT). The primary endpoint of the study was to evaluate the relationship between mrTRG and pTRG after nCRT. The secondary endpoint of the study was to evaluate the variables that affect mrTRG and pTRG.
METHODS
Forty-one patients with LARC treated with nCRT were analyzed. Magnetic resonance imaging (MRI)
performed after nCRT was compared with MRI taken before nCRT. Changes in T and N stages and
extramural vascular invasion positivity were investigated. TRG was divided into five groups in terms
of pathological and MRI. The Dworak pTRG system was used for compatibility testing. MRI sensitivity
and specificity were evaluated by comparing MRI-based response assessment with pathological assessment
after nCRT.
RESULTS
Median patient age was 61 years (range, 26?79 years), and 18 (43.9%) were female. The relationship
between mrTRG and pTRG was evaluated with the Cohen kappa coefficient. Significant compatibility
was observed between pTRG and mrTRG (p=0.002), but the compatibility was low (kappa compatibility,
0.319). The sensitivity of mrTRG was 90% (18/20); specificity was 14.3% (3/21); positive predictive value
was 85.7% (18/21); and negative predictive value was 90% (18/20). While pTRG was negatively affected
by advanced age (p=0.037), mrTRG was adversely affected by advanced post-nCRT N stage (p=0.048).
CONCLUSION
As age increased, pTRG was negatively affected; as the post-nCRT N stage increased, mrTRG was negatively
affected. There was compatibility between mrTRG and pTRG, as expected, but this compatibility
was found to be low.