Fusion image of positron emission tomography and computed tomography for the diagnosis of local recurrence of rectal cancer.

Background: The aim of this study was to evaluate the clinical and therapeutic value of digital fusion image (FI) of positron emission tomography (PET) using (18)F-fluorodeoxy glucose and computed tomography (CT) in patients who were suspected of having a local recurrence of rectal cancer.
Methods: Forty-two patients (32 men and 10 women; mean age, 61.4 years, range, 40-79 years) with a suspicion of local recurrence after curative resection of rectal cancer were prospectively recruited and underwent (18)F-fluorodeoxy glucose-PET and CT. The FI was reconstructed with a commercially available digital software program, T-B Fusion. Wilcoxon signed rank test was used to compare FI with CT alone or PET alone.
Results: FI yielded a correct diagnosis in 39 (93%) of 42 patients, whereas CT alone and PET alone did so in 33 (79%) and 37 (88%) patients, respectively. FI had better diagnostic accuracy than CT alone (P = .0138) and PET alone (P = .0156). Overall, FI altered patient management in 11 (26.2%) patients on the basis of additional information, including differentiation of the tumor from the postoperative scar in 6 patients, exact anatomical location in 3 patients, and both in 2 patients.
Conclusions: FI has a potential clinical value in the treatment of suspected local recurrence of rectal cancer.