Evaluating the Role of Urinalysis for Suspected Cystitis in Women Undergoing Pelvic Radiotherapy

The aims of this study were to analyze the effectiveness of urinalysis parameters in predicting positive urine culture and to characterize urinary tract infections in gynecologic cancer patients receiving pelvic radiotherapy.

The records of 134 women receiving pelvic radiotherapy were retrospectively analyzed with a total of 241 urine specimens. Dipstick, urine microscopy, and urine culture data were recorded. Sensitivity, specificity, positive and negative predictive values, and diagnostic odds ratios of dipstick and microscopy components for predicting positive urine culture were calculated. Organisms isolated from positive cultures and their antibiotic resistance data were recorded.

A total of 84 urine cultures (34.9%) were positive for growth. The presence of either urine nitrites, leukocyte esterase, or both had the highest sensitivity (91.7%) of all tested parameters for predicting a positive urine culture. The presence of both urine white blood cells and urine nitrites had the highest specificity (95.5%), positive predictive value (75.0%), and diagnostic odds ratio (7.21 [2.92-17.83]), whereas the absence of urine white blood cells had the highest negative predictive value (87.0%). Escherichia coli was the most common grown in culture, isolated from 19 specimens (22.6%). When antibiotic sensitivity analysis was performed, 23.8% of pathogens were resistant to trimethoprim/sulfamethoxazole, 16.7% were resistant to ciprofloxacin, and 11.1% were resistant to nitrofurantoin.

Urinalysis may be less accurate for predicting urinary tract infection in women undergoing pelvic RT compared with the general population, but is still useful. Escherichia coli was less common than expected, and the rate of resistance to first-line antibiotics was relatively high, underscoring the importance of culture and sensitivity testing in order to confirm the efficacy of empiric antibiotic therapy.