RPS 607 - New ultrasound modalities in the genitourinary system

Purpose:

To investigate how long after cryoablation successfully ablated tumours became completely avascular at CEUS.

Methods and materials:

Between January 2012 and January 2018, 79 patients (55 men, 24 women, median and average age: 73 yo; range 46-89 yo) with 82 renal tumours treated with percutaneous cryoablation underwent CEUS before the procedure and at postoperative day one. If the lesion was avascular at the CEUS performed at postoperative day one, no further imaging was obtained before the reference contrast-CT/MR scheduled six months after the procedure. If the lesion still displayed enhancement at postoperative day one, CEUS was repeated up to the disappearance of the intralesional vascularity after one week, two weeks, one month, and three months, if necessary.

Results:

The reference contrast-CT/MR obtained six months after the ablation procedure showed 80 successfully ablated tumours and two cases of tumour persistence. 46/80 (57%) successfully ablated tumours were avascular on postoperative day one, 67/80 (84%) within one week, 72/80 (90%) within two weeks. All successfully ablated tumours were avascular after one month. The two lesions with tumour persistence displayed intralesional vascularity after three months.

Conclusion:

After successful cryoablation, intralesional enhancement disappears within two weeks in the majority of cases but can persist for up to one month.

Limitations:

A retrospective study.

Ethics committee approval

n/a

Funding:

No funding was received for this work.

Purpose:

The purpose of this study was to compare diagnostic accuracy between contrast-enhanced ultrasound (CEUS) qualitative parameters and conventional ultrasound (US) based IOTA simple rules (SR) in patients with sonographically complex adnexal masses, using histopathology as a gold standard.

Methods and materials:

This Institutional Review Board approved prospective study consisted of 70 consenting patients with 70 complex adnexal masses. Conventional US examination was followed by CEUS using intravenous administration of 4.8 ml of second-generation ultrasound contrast agent. Tumours larger than 10 cm were examined by a transabdominal route and the rest transvaginally. Tumours were categorised into “benign”, “malignant”, or “inconclusive” based on IOTA SR. CEUS qualitative parameters evaluated were enhancement order, extent, and pattern relative to the myometrium, with at least two features required for categorisation. Histopathology diagnosis was obtained for all tumours. The diagnostic accuracy of qualitative parameters and IOTA SR was obtained.

Results:

Of 70 patients, 34 (48.6%) were benign and 36 (51.4%) were malignant. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for IOTA SR were 87.5%, 79.2%, 89.5%, and 76%, while for CEUS qualitative parameters these were 93.6%, 86.4%, 96.1%, and 79.2%.The type of enhancement showed highest sensitivity (94.9%), specificity (90.5%), PPV (97.4%), and NPV (82.6%). Accuracy for CEUS qualitative parameters was 92%, while for conventional US based IOTA SR was 84.7%, p <0.05.

Conclusion:

CEUS qualitative parameters were found to have better diagnostic accuracy than conventional US-based IOTA SR for the characterisation of sonographically complex adnexal masses. The technique holds potential not only for reducing invasive biopsies/diagnostic laparotomy but also is of immense clinical utility in patients with impaired renal function.

Limitations:

A single-centre study with a imited number of patients.

Ethics committee approval

Ethics committee approval obtained.

Funding:

No funding was received for this work.

Purpose:

To evaluate the diagnostic accuracy of contrast-enhanced ultrasound (CEUS) quantitative parameters for the characterisation of solid renal masses, using histopathology as a gold standard.

Methods and materials:

In this Institutional Review Board approved prospective study, 52 consenting patients with solitary solid renal masses were recruited. Conventional ultrasound (US) was performed, followed by CEUS with 1.2 ml bolus intravenous injection of second-generation ultrasound contrast agent. For every tumour, a time-intensity curve was constructed and peak enhancement (PE), time to peak (TTP), area under the time-intensity curve (AUTIC), and mean transit time (MTT) were documented. Multiple linear regression and ROC curves were used to evaluate cut-off values and the diagnostic accuracy of CEUS quantitative parameters.

Results:

Of 52 patients evaluated, 6 (11.5%) were benign and 46 (88.5%) malignant on histopathology. TTP and MTT showed reliable accuracy for the characterisation of solid renal masses. For TTP, considering cut-off of 18s, sensitivity, specificity, PPV, and NPV were 97.73%, 75%, 95.56%, and 85.71%, respectively (AUC 0.94). For MTT, considering cut-off of 28s, the same were 95.65%, 83.33%, 97.78%, and 71.43%, respectively (AUC 0.93). Neither AUTIC (cut-off >3100, AUC 0.68) nor PE (cut-off >17, AUC 0.65) were independently capable for the characterisation of solid renal masses. Using all four criteria, sensitivity, specificity, PPV, and NPV were 95.4%, 47.1%, 90.2%, and 66.7%, respectively (p<0.05).

Conclusion:

CEUS quantitative parameters have a significant role in the characterisation of solid renal masses. The technique holds potential not only for reducing exposure to iodinated contrast and radiation dosage but is of great clinical utility in patients with impaired renal function, in whom iodinated/gadolinium-based contrast agents are contraindicated.

Limitations:

A single-centre study.

Ethics committee approval

Informed consent from all patients. Animal board approval N/A.

Funding:

No funding was received for this work.