Instant 99mTc-ciprofloxacin scintigraphy for the diagnosis of osteomyelitis in the diabetic foot.
BACKGROUND
The diagnosis of osteomyelitis of the foot in patients with diabetes mellitus remains a challenge. This study was conducted to evaluate bone infections using scintigraphy with instantly prepared single-vial kit, radio-labeled ciprofloxacin (Diagnobact TM) in comparison to a bacterial culture taken from the involved site.


METHODS
Twenty-five patients with type 2 diabetes mellitus having foot ulcers, including six with superficial ulcers and positive 99mTc-methylene diphosphonate (MDP) bone scan as a control, were subjected to 99mTc-ciprofloxacin scan and subsequent bacteriological culture.


RESULTS
99mTc-ciprofloxacin scan was positive in 13 patients and negative in 12 patients, including the six with superficial ulcers. Bacterial culture was positive in 18 patients and negative in seven, including one with osteomyelitis on bone biopsy only. 99mTc-ciprofloxacin scan showed "true positive" results in 12, "true negative" in six, "false positive" in one, and "false negative" in six. The specificity and sensitivity of the test were 66.7% and 85.7%, respectively. The positive and negative predictive values and an accuracy of 92.8%, 50% and 72%, respectively. Staphylococcus aureus and Escherichia coli were the most frequently isolated organisms.


CONCLUSIONS
99mTc-ciprofloxacin is a sensitive and specific marker to diagnose bone infection in patients with diabetes mellitus, but care must be taken in case of fastidious organisms and ciprofloxacin-resistant bacterial flora in which false results may be obtained.
Dutta
Pinaki
P
Endocrinology, PGIMER, Chandigarh, UT, India.
Bhansali
Anil
A
Mittal
Bhagwant R
BR
Singh
Baljnder
B
Masoodi
Sariq R
SR
D000328:Adult; D000368:Aged; D002939:Ciprofloxacin / Q000031:analogs & derivatives*; D017719:Diabetic Foot / Q000150:complications* / Q000382:microbiology; D004926:Escherichia coli / Q000302:isolation & purification; D006801:Humans; D008875:Middle Aged; D015609:Organotechnetium Compounds; D010019:Osteomyelitis / Q000150:complications / Q000175:diagnosis* / Q000000981:diagnostic imaging; D011446:Prospective Studies; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D013211:Staphylococcus aureus / Q000302:isolation & purification
D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C431804:Technetium Tc 99m ciprofloxacin; D002939:Ciprofloxacin