CT-guided cryoablation of renal cancer: radiation burden and the associated risk of secondary cancer from procedural- and follow-up imaging

Dataset on renal tumor diameter assessment by multiple observers in normal-dose and low-dose CT

Computed tomography-based active surveillance is increasingly used to manage small renal tumors, regardless of patient age. However, there is an unmet need for decreasing radiation exposure while maintaining the necessary accuracy and reproducibility in radiographic measurements, allowing for detecting even minor changes in renal mass size. In this article, we present supplementary data from a multiobserver investigation. We explored the accuracy and reproducibility of low-dose CT (75% dose reduction) compared to normal-dose CT in assessing maximum axial renal tumor diameter. Open-access CT datasets from the 2019 Kidney and Kidney Tumor Segmentation Challenge were used. A web-based platform for assessing observer performance was used by six radiologist observers to obtain and provide data on tumor diameters and accompanying viewing settings, in addition to key images of each measurement and an interactive module for exploring diameter measurements. These data can serve as a baseline and inform future studies investigating and validating lower-dose CT protocols for active surveillance of small renal masses.

MRI- Versus CT-Guided Renal Tumor Cryoablation: Is There a Difference?

PURPOSE

To compare procedure-related variables, safety, renal function, and oncologic outcomes in patients undergoing percutaneous cryoablation (CA) of renal tumors with MRI- or CT-guidance.

MATERIALS AND METHODS

Patient, tumour, procedure, and follow-up data were collected and analysed. MRI and CT groups were matched using a coarsened exact approach according to patient's gender and age, tumour grade, size and location. P < 0.05 was considered statistically significant.

RESULTS

Two-hundred fifty-three patients (266 tumors) were retrospectively selected. Following the coarsened exact matching 46 patients (46 tumors) in the MRI group and 42 patients (42 tumors) in the CT group were matched. There were no significant baseline differences between the two populations except for the duration of follow-up (P = 0.002) and renal function (P = 0.002). On average MRI-guided CA lasted 21 min longer than CT-guided ones (P = 0.005). Following CA, complication rates (6.5% for MRI vs 14.3% for CT; P = 0.30) and GFR decline (mean - 13.1 ± 15.8%; range - 64.5-15.0 for MRI; mean - 8.1 ± 14.8%; range - 52.5-20.4; for CT; P = 0.13) were similar in both groups. The 5-year local progression-free, cancer-specific and overall survivals in the MRI and CT groups were 94.0% (95% CI 86.3%-100.0%) and 90.8% (95% CI 81.3%-100.0%; P = 0.55), 100.0% (95% CI 100.0%-100.0%) and 100.0% (95% CI 100.0%-100.0%; P = 1), and 83.7% (95% CI 64.0%-100.0%) and 76.2% (95% CI 62.0%-93.6%; P = 0.41), respectively.

CONCLUSIONS

Apart from increased procedural times associated with MRI-guided CA of renal tumors compared to CT-guidance, both modalities demonstrate similar safety, GFR decline and oncologic outcomes.

Percutaneous CT-Guided Renal Cryoablation: Technical Aspects, Safety, and Long-Term Oncological Outcomes in a Single Center

Background and objectives: Cryoablation is emerging as a safe and effective therapeutic option for treating renal cell carcinoma. This study analyzed the safety and long-term oncological outcomes of cryoablation in our center. Materials and methods: Patients who underwent computed tomography (CT)-guided percutaneous cryoablation between February 2011 and June 2020 for one or more clinically localized renal tumors were identified. Technical success and treatment efficacy were assessed. Post-procedural complications were classified according to the Clavien-Dindo system. Recurrence-free survival was determined for biopsy-proven malignant renal tumors. Results: A total of 174 renal tumors, 78 of which were biopsy-proven malignant carcinomas, were treated in 138 patients (97 males and 41 females, mean age: 73 years, range: 43-89 years). Mean tumor size was 2.25 cm and 54.6% of the lesions required a complex approach. Technical success was achieved in 171 out of 174 tumors (98.3%). Primary treatment efficacy was 95.3% and increased to 98.2% when retreats were taken into account. The overall complication rate was 29.8%. No complications of Clavien-Dindo grade III or more were encountered. Median follow-up was 21.92 months (range: 0.02-99.87). Recurrence-free survival was 100% at 1 year, 95.3% (95% CI: 82.1%-98.8%) at 3 years, and 88.6% (95% CI: 71.8%-95.7%) at 5 years. Conclusions: Cryoablation is a safe and effective technique for the treatment of small renal lesions, with no major complications when performed by expert interventional radiologists. The multidisciplinary discussion is essential, especially considering the high number of histologically undetermined lesions. Our long-term oncological outcomes are encouraging and in line with the literature.