Restaging of locally advanced carcinoma of the rectum with MR imaging after preoperative radio-chemotherapy plus regional hyperthermia.
BACKGROUND
The restaging accuracy of MR imaging in advanced primary rectal carcinoma after preoperative radiochemotherapy and regional hyperthermia was evaluated and compared with the histopathologically verified degree of tumor remission after a course of radio-chemo-thermotherapy.


METHODS
35 patients with primary rectal carcinoma (uT3/uT4) underwent MRI using a surface coil 4-6 weeks after radiochemotherapy (n = 35), regional hyperthermia (n = 23), and before curative surgery. We defined as gold standard for the remission status the comparison of pretherapeutic endosonography with the histopathology of the resected specimen.


RESULTS
T category was correctly restaged after preoperative treatment in only 19 (54%) of 35 patients. Nine of 20 responders were overstaged and seven of 15 non-responders were understaged. Concurrently, the N category was correctly restaged in 19 (54%) of 35 patients (twelve responders and seven non-responders). Overstaging occurred in four responders and two non-responders, understaging occurred in four responders and six non-responders.


CONCLUSIONS
MRI proved independent of the response status as not suitable to restage locally advanced rectal carcinoma after preoperative radiochemotherapy despite optimized imaging technique and spatial resolution. Basically, imaging the morphology of a tumor cannot clearly differentiate between vital and devitalized tissue after a treatment. Functional imaging such as PET (positron emission tomography) appears more feasible for restaging after radio-chemo-thermotherapy.
Hoffmann
Karl-Titus
KT
Department of Radiology and Radiation Oncology, Campus Virchow-Klinikum, Charité. karl-titus.hoffmann@charite.de
Rau
Beate
B
Wust
Peter
P
Stroszczynski
Christian
C
Hünerbein
Michael
M
Schneider
Ulrike
U
Felix
Roland
R
D000328:Adult; D000368:Aged; D003131:Combined Modality Therapy; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D006979:Hyperthermia, Induced; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging; D012004:Rectal Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D012007:Rectum / Q000473:pathology / Q000601:surgery; D012680:Sensitivity and Specificity; D016896:Treatment Outcome