Early detection is important for all cancers, but it's particularly crucial for the often-deadly gallbladder carcinoma. Contrast-enhanced ultrasound (CEUS) can be a useful weapon in the battle to diagnose gallbladder cancer sooner, according to researchers from China.
In a study involving 64 patients, CEUS yielded significant improvements over conventional ultrasound in sensitivity, specificity, and accuracy for diagnosing gallbladder cancer.
"CEUS is a valuable imaging tool for differentiating malignant and benign gallbladder lesions," said Dr. Liping Liu from the First Hospital of Shanxi Medical University in Taiyuan. She presented the research during a session at the recent American Institute of Ultrasound in Medicine (AIUM) annual conference in Orlando, FL.
Importance of early detection
While gallbladder lesions can be benign conditions such as polyps, adenomyomatosis, adenomas, or biliary sludge, patients with malignant lesions often have a poor prognosis, Liu said. Early detection -- and subsequent surgery -- can increase the five-year survival rate, however.
To determine if contrast ultrasound could improve upon the performance of conventional ultrasound, the researchers studied 64 patients between August 2007 and April 2014 who were suspected of having lesions in the gallbladder based on conventional ultrasound. The 64 subjects included 22 men and 42 women with an average age of 54.3 ± 14.3 years.
The patients were scanned using a Logiq 9 (GE Healthcare) or MyLab 90 (Esaote) system with a contrast-tuned imaging (CnTI) protocol, along with the SonoVue ultrasound contrast agent (Bracco Imaging).
Of the 64 patients, 20 showed no enhancement in the gallbladder on CEUS and were diagnosed with gallbladder sludge. As a result, these patients avoided surgery, Liu said. The remaining 44 patients with solid gallbladder lesions underwent surgery; this group had 15 polyps, six cases of adenomyomatosis, three adenomas, and 20 carcinomas.
| Performance in diagnosing gallbladder cancer | ||
| Measure | Conventional ultrasound | CEUS |
| Sensitivity | 70% | 95% |
| Specificity | 83.3% | 95.8% |
| Accuracy | 77.2% | 95.4% |
The time to enhancement was 14.05 ± 3.33 seconds for malignant lesions, compared with 17.46 ± 3.92 seconds for benign lesions, a statistically significant difference (p = 0.004). The difference in time to peak intensity between malignant lesions (22.05 ± 5.93 seconds) and benign lesions (24.25 ± 5.79 seconds) did not reach statistical significance, however (p = 0.223).
| CEUS characteristics of 44 gallbladder lesions | ||
| Characteristic | Malignant (n = 20) | Benign (n = 24) |
| Arterial-phase hypoenhancement | 16 (80%) | 15 (62.5%) |
| Arterial-phase isoenhancement | 4 (20%) | 9 (37.5%) |
| Late-phase hypoenhancement | 17 (85%) | 7 (29.2%) |
| Late-phase isoenhancement | 3 (15%) | 17 (70.8%) |
| Heterogenous enhanced pattern | 12 (60%) | 5 (20.8%) |
| Homogenous enhanced pattern | 8 (40%) | 19 (79.2%) |
Contrast enhancement differences
Hypoenhancement of the late phase and enhancement pattern showed statistically significant differences between benign and malignant gallbladder lesions (p < 0.05).
"Most gallbladder carcinoma demonstrated heterogenous enhancement and hypoenhancement of the late phase because malignant tumors have vessel distortion and their tissue and structure is nonuniform," she said.
In addition, 14 (70%) of the 20 malignant lesions showed gallbladder wall destruction, Liu said.
"CEUS can reveal gallbladder cancer to infiltrate the gallbladder wall and adjacent hepatic parenchyma," she said.
