Neoadjuvant radiochemotherapy of oral cavity and oropharyngeal cancer: evaluation of tumor response by CT differs from histopathologic response assessment in a significant fraction of patients.
BACKGROUND
Our aim was to compare and assess the predictive value of CT and histopathologic grading of tumor regression at primary tumor sites in patients with squamous cell carcinoma of the oral cavity and oropharynx after neoadjuvant (preoperative) radiochemotherapy (RCT).


METHODS
We investigated 55 patients with carcinomas of the oral cavity and oropharynx who underwent RCT before curative surgery. Two blinded observers measured RCT-induced reduction of tumor volume in pretherapeutic and posttherapeutic CT scans. Volume changes were compared with histopathologic findings obtained at surgery.


RESULTS
Histopathologic response evaluation revealed 31 complete remissions, 12 cases of partial response, and 12 nonresponders. We performed a logistic regression analysis to evaluate whether measured volume reduction could predict the likelihood of belonging to a certain response group. Taken together, we found 35 correct, 12 false-negative, and seven false-positive predictions.


CONCLUSIONS
The extent of remission as assessed by CT scans 4 to 5 weeks after completion of neoadjuvant RCT leads to false predictions in a significant percentage of patients.
Klug
Clemens
C
Department of Cranio-Maxillofacial and Oral Surgery, Medical University of Vienna, AKH, Waehringer Gürtel 18-20, A-1090 Vienna, Austria. clemens.klug@univie.ac.at
Keszthelyi
David
D
Ploder
Oliver
O
Sulzbacher
Irene
I
Voracek
Martin
M
Wagner
Arne
A
Millesi
Werner
W
Kornek
Gabriele
G
Kainberger
Franz
F
Kermer
Christian
C
Selzer
Edgar
E
D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000628:therapy; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000628:therapy; D020360:Neoadjuvant Therapy; D009959:Oropharyngeal Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000628:therapy; D017063:Outcome Assessment, Health Care; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed