Reliability of white blood cell scan in the follow-up of osteomyelitis.
BACKGROUND
The question of whether antibiotic treatment does or does not affect reliability of white blood cell scan (WBCS) to detect disease activity in clinical practice is still unanswered. Our aim was to study the relationship between scintigraphic findings of WBCS and antibiotic therapy in a group of patients affected with osteomyelitis (OM).


METHODS
We retrospectively reviewed 57 scans, performed in 18 patients affected by OM and who were on antibiotic treatment. The number of therapy weeks was calculated for each antibiotic. A comparison of results obtained during and after discontinuation of the antibiotic treatment was made. Overall sensitivity, specificity and accuracy of WBCS were calculated and compared with those obtained in patients undergoing therapy.


RESULTS
Forty-seven scans were performed during treatment and 10 scans after discontinuation of treatment. The scintigraphic results obtained during and after discontinuation of treatment were as follows: TN 14 and 8, TP 31 and 2, FN 2 and 0, FP 0 and 0, respectively. Sensitivity, specificity and accuracy of WBCS, calculated in all patients, were 94.3%, 100% and 96.5% respectively. In patients receiving antibiotic therapy, the same parameters were 93.9%, 100% and 95.7% respectively. In patients treated with antibiotics that can decrease leukocyte function, there were 10 TN, 14 TP, 2 FN and 0 FP, while in patients treated with antibiotics that have not effect on leukocyte function there were 4 TN, 17 TP, 0 FN and 0 FP.


CONCLUSIONS
The reliability of WBCS in the detection of disease activity during antibiotic treatment does not change significantly. It can be assumed that the influence of antibiotic therapy on labelled leukocyte behaviour is negligible.
Liberatore
Mauro
M
Nuclear Medicine Unit, Department of Radiological Sciences, University of Rome La Sapienza, Rome, Italy.
Calandri
Enrico
E
Pavoni
Gian Luca
GL
Baiocchi
Pia
P
Iurilli
Anna Paola
AP
Venditti
Mario
M
Al-Nahhas
Adil
A
Rubello
Domenico
D
D000293:Adolescent; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007962:Leukocytes / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D010019:Osteomyelitis / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D011877:Radionuclide Imaging; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013997:Time Factors
D000900:Anti-Bacterial Agents