Real-Time US-CT fusion imaging for guidance of thermal ablation in of renal tumors invisible or poorly visible with US: results in 97 cases

Thermal Ablation for Small Renal Masses: Identifying Anthropometric Factors for Predicting Perioperative and Oncological Outcomes

OBJECTIVES

To test for specific anthropometric parameters to predict perioperative outcomes after thermal ablation (TA) for renal cell carcinoma (RCC).

MATERIALS AND METHODS

Retrospective single center (2008-2022) analysis of 538 T1a-b RCC patients treated with TA. We tested for specific anthropometric parameters, namely skin to tumor distance (STTD), perirenal fat thickness (PFT), median psoas muscle axial area (PMAA) and median paravertebral muscle axial area (PVMAA), to predict TRIFECTA achievement: (1) absence of CLAVIEN-DINDO≥ 3 complications; (2) complete ablation; (3) absence of ≥ 30% decrease in eGFR. Univariable (ULRM) and multivariable logistic regression models (MLRM) were used for testing TRIFECTA achievement.

RESULTS

Overall, 103 patients (19%) did not achieve TRIFECTA. Of all anthropometric factors, only lower PMAA was associated with no TRIFECTA achievement (10 vs. 11 cm2, P = .02). However, ULRMs and MLRMs did not confirmed the aforementioned association. We than tested for the 3 specific TRIFECTA items. In separate ULRM and MLRM predicting incomplete ablation, both continuously coded STTD (Odds Ratio [OR]: 1.02; CI: 1.01-1.03; P = .02) and STTD strata (STTD > 10 cm; OR: 2.1; CI: 1.1-4.1; P = .03) achieved independent predictor status. Conversely, in separate ULRM and MLRM predicting CLAVIEN-DINDO ≥3 complications, both continuously coded PFT (OR: 1.04; CI: 1.01-1.07; P = .01) and PFT strata (PFT ≥ 14 mm; OR: 3.3; CI: 1.6-10.2; P = .003) achieved independent predictor status. Last, none of the anthropometric parameters were associated with eGFR decrease ≥ 30%.

CONCLUSION

None of the tested anthropometric parameters predicted TRIFECTA achievement. However, when the 3 specific TRIFECTA items were tested, STTD and PFT were associated with, respectively, incomplete ablation and CLAVIEN-DINDO ≥ 3 complications.

Artificial intelligence in interventional radiology: state of the art

Artificial intelligence (AI) has demonstrated great potential in a wide variety of applications in interventional radiology (IR). Support for decision-making and outcome prediction, new functions and improvements in fluoroscopy, ultrasound, computed tomography, and magnetic resonance imaging, specifically in the field of IR, have all been investigated. Furthermore, AI represents a significant boost for fusion imaging and simulated reality, robotics, touchless software interactions, and virtual biopsy. The procedural nature, heterogeneity, and lack of standardisation slow down the process of adoption of AI in IR. Research in AI is in its early stages as current literature is based on pilot or proof of concept studies. The full range of possibilities is yet to be explored.Relevance statement Exploring AI's transformative potential, this article assesses its current applications and challenges in IR, offering insights into decision support and outcome prediction, imaging enhancements, robotics, and touchless interactions, shaping the future of patient care.Key points• AI adoption in IR is more complex compared to diagnostic radiology.• Current literature about AI in IR is in its early stages.• AI has the potential to revolutionise every aspect of IR.

Imaging in interventional oncology, the better you see, the better you treat

Imaging and image processing is the fundamental pillar of interventional oncology in which diagnostic, procedure planning, treatment and follow-up are sustained. Knowing all the possibilities that the different image modalities can offer is capital to select the most appropriate and accurate guidance for interventional procedures. Despite there is a wide variability in physicians preferences and availability of the different image modalities to guide interventional procedures, it is important to recognize the advantages and limitations for each of them. In this review, we aim to provide an overview of the most frequently used image guidance modalities for interventional procedures and its typical and future applications including angiography, computed tomography (CT) and spectral CT, magnetic resonance imaging, Ultrasound and the use of hybrid systems. Finally, we resume the possible role of artificial intelligence related to image in patient selection, treatment and follow-up.

Predicting Peri-Operative Outcomes in Patients Treated with Percutaneous Thermal Ablation for Small Renal Masses: The SuNS Nephrometry Score

Our objective was to develop a new, simple, and ablation-specific nephrometry score to predict peri-operative outcomes and to compare its predictive accuracy to PADUA and RENAL scores. Overall, 418 patients were treated with percutaneous thermal ablation (microwave and radiofrequency) between 2008 and 2021. The outcome of interest was trifecta status (achieved vs. not achieved): incomplete ablation or Clavien-Dindo ≥ 3 complications or postoperative estimated glomerular filtration rate decrease ≥ 30%. First, we validated the discrimination ability of the PADUA and RENAL scoring systems. Second, we created and internally validated a novel scoring (SuNS) system, according to multivariable logistic regression models. The predictive accuracy of the model was tested in terms of discrimination and calibration. Overall, 89 (21%) patients did not achieve trifecta. PADUA and RENAL scores showed poor ability to predict trifecta status (c-indexes 0.60 [0.53-0.67] and 0.62 [0.55-0.69], respectively). We, therefore, developed the SuNS model (c-index: 0.74 [0.67-0.79]) based on: (1) contact surface area; (2) nearness to renal sinus or urinary collecting system; (3) tumour diameter. Three complexity classes were created: low (3-4 points; 11% of no trifecta) vs. moderate (5-6 points; 30% of no trifecta) vs. high (7-8 points; 65% of no trifecta) complexity. Limitations include the retrospective and single-institution nature of the study. In conclusion, we developed an immediate, simple, and reproducible ablation-specific nephrometry score (SuNS) that outperformed PADUA and RENAL nephrometry scores in predicting peri-operative outcomes. External validation is required before daily practice implementation.

Image-Guided Ablations in Patients with Recurrent Renal Cell Carcinoma

Renal cell carcinoma (RCC) is one of the most frequently diagnosed tumors and a leading cause of death. The high risk of local recurrence and distant metastases represent a significant clinical issue. Different image-guided ablation techniques can be applied for their treatment as an alternative to surgery, radiotherapy or systemic treatments. A retrospective analysis was conducted at our institution, including a total number of 34 RCC patients and 44 recurrent RCC tumors in different locations (kidney, lung, adrenal gland, liver, pancreas, pararenal and other) using microwave ablation, radiofrequency ablation, cryoablation and laser ablation. The estimated time to local and distant tumor progression after treatment were 22.53 ± 5.61 months and 24.23 ± 4.47 months, respectively. Systemic treatment was initiated in 10/34 (29%) treated patients with a mean time-to-systemic-therapy of 40.92 ± 23.98 months. Primary technical success was achieved in all cases and patients while the primary efficacy rate was achieved in 43/44 (98%) cases and 33/34 (97%) patients, respectively, with a secondary technical success and efficacy rate of 100%. At a mean follow-up of 57.52 months ± 27.86 months, local tumor progression occurred in 3/44 (7%) cases and distant progression in 25/34 (74%) patients. No significant complications occurred. Image-guided ablations can play a role in helping to better control recurrent disease, avoiding or delaying the administration of systemic therapies and their significant adverse effects.

Ultrasound nanotheranostics: Toward precision medicine

Ultrasound (US) is a mechanical wave that can penetrate biological tissues and trigger complex bioeffects. The mechanisms of US in different diagnosis and treatment are different, and the functional application of commercial US is also expanding. In particular, recent developments in nanotechnology have led to a wider use of US in precision medicine. In this review, we focus on US in combination with versatile micro and nanoparticles (NPs)/nanovesicles for tumor theranostics. We first introduce US-assisted drug delivery as a stimulus-responsive approach that spatiotemporally regulates the deposit of nanomedicines in target tissues. Multiple functionalized NPs and their US-regulated drug-release curves are analyzed in detail. Moreover, as a typical representative of US therapy, sonodynamic antitumor strategy is attracting researchers' attention. The collaborative efficiency and mechanisms of US and various nano-sensitizers such as nano-porphyrins and organic/inorganic nanosized sensitizers are outlined in this paper. A series of physicochemical processes during ultrasonic cavitation and NPs activation are also discussed. Finally, the new applications of US and diagnostic NPs in tumor-monitoring and image-guided combined therapy are summarized. Diagnostic NPs contain substances with imaging properties that enhance US contrast and photoacoustic imaging. The development of such high-resolution, low-background US-based imaging methods has contributed to modern precision medicine. It is expected that the integration of non-invasive US and nanotechnology will lead to significant breakthroughs in future clinical applications.

Thermal ablation for small renal masses: Identifying the most appropriate tumor size cut-off for predicting perioperative and oncological outcomes

OBJECTIVES

To test TRIFECTA achievement [1) absence of CLAVIEN-DINDO ≥3 complications; 2) complete ablation; 3) absence of ≥30% decrease in eGFR] and local recurrence rates, according to tumor size, in patients treated with thermal ablation (TA: radiofrequency [RFA] and microwave ablation [MWA]) for small renal masses.

METHODS

Retrospective analysis (2008-2020) of 432 patients treated with TA (RFA: 162 vs. MWA: 270). Tumor size was evaluated as: 1) continuously coded variable (cm); 2) tumor size strata (0.1-2 vs. 2.1-3 vs. 3.1-4 vs. >4 cm). Multivariable logistic regression models and a minimum P-value approach were used for testing TRIFECTA achievement. Kaplan-Meier plots depicted local recurrence rates over time.

RESULTS

Overall, 162 (37.5%) vs. 140 (32.4%) vs. 82 (19.0%) vs. 48 (11.1%) patients harboured, respectively, 0.1 to 2 vs. 2.1 to 3 vs. 3.1 to 4 vs. >4 cm tumors. In multivariable logistic regression models, increasing tumor size was associated with higher rates of no TRIFECTA achievement (OR:1.11; P< 0.001). Using a minimum P-value approach, an optimal tumor size cut-off of 3.2 cm was identified (P< 0.001). In multivariable logistic regression models, 3.1 to 4 cm tumors (OR:1.27; P< 0.001) and >4 cm tumors (OR:1.49; P< 0.001), but not 2.1 to 3 cm tumors (OR:1.05; P= 0.3) were associated with higher rates of no TRIFECTA achievement, relative to 0.1 to 2 cm tumors. The same results were observed in separate analyses of RFA vs. MWA patients. After a median (IQR) follow-up time of 22 (12-44) months, 8 (4.9%), 8 (5.7%), 11 (13.4%), and 5 (10.4%) local recurrences were observed in tumors sized 0.1 to 2 vs. 2.1 to 3 vs. 3.1 to 4 vs. >4 cm, respectively (P= 0.01).

CONCLUSION

A tumor size cut-off value of ≤3 cm is associated with higher rates of TRIFECTA achievement and lower rates of local recurrence over time in patients treated with TA for small renal masses.

US-CT fusion-guided percutaneous radiofrequency ablation of large substernal benign thyroid nodules

The aim of the present study was to assess feasibility, safety and outcome of ultrasound (US) guided percutaneous radiofrequency (RF) ablation of large substernal benign thyroid nodules assisted by US-computed tomography (CT) fusion imaging and real-time virtual needle tracking (VT) system. Thirty patients (18 females, mean age 56 y, range 32-76 y) with 35 benign nonfunctioning thyroid nodules (mean volume ± SD 26.8 ± 7.6 mL; range 20-38mL) were selected for CT-US fusion guided RF ablation. Nodules' volume was evaluated before treatment and during 12-months follow-up. Complications' rate was also evaluated. US-CT fusion imaging with VT system was feasible in all cases (feasibility 100%) and it was always possible to complete the procedure as planned (technical success 100%). Minor complications occurred in 2/30 cases (6.6%). No major complications occurred. 50% volume reduction (technique efficacy) was achieved in 93% cases, with a significant mean volume reduction at 12 months follow-up (68.7 ± 10.8%), (p < .001). The VT system could be useful in thyroid nodules ablation procedures assistance being able to track the RF electrode tip even when this is obscured by the bubbles produced by the ablative process. The combination of fusion imaging with VT assisted RF ablation represents a safe, non-surgical treatment option for patients with large substernal benign thyroid nodules.

Radiofrequency ablation using real-time ultrasonography–computed tomography fusion imaging improves treatment outcomes for T1a renal cell carcinoma: Comparison with laparoscopic partial nephrectomy

Purpose

To determine whether real-time ultrasonography–computed tomography (US-CT) fusion imaging can improve technical feasibility versus B-mode US and provide comparable outcomes of radiofrequency ablation (RFA) for T1a renal cell carcinoma (RCC) compared with laparoscopic partial nephrectomy (LPN).

Materials and Methods

Between June 2013 and August 2016, biopsy- or pathologically confirmed stage T1a RCCs were retrospectively reviewed. Of these, 39 cases were included in the RFA group, and 46 cases were included in the LPN group. In the RFA group, we evaluated tumor visibility and technical feasibility before RFA on a four-point scale on B-mode US and US-CT fusion images. After RFA, hospital days, creatinine value, complications, and disease-free survival rate were compared between the two groups. All results were analyzed by use of the Mann–Whitney U-test and Kaplan–Meier method.

Results

Compared with B-mode US alone, real-time US-CT fusion significantly improved the tumor visibility score and overall mean technical feasibility grade (p<0.001). The 5-year disease-free survival rate was 97.4% and 97.8% in the RFA and LPN groups, respectively, and there was no statistically significant difference between groups (p=0.1). Mean periprocedural creatinine levels were significantly lower in the RFA group than in the LPN group. The number of hospital days was shorter in the RFA group. Minor complications were present in 5.1% of the RFA group and 13.0% of the LPN group, with no major complications.

Conclusions

US-CT fusion-image-guided RFA improved tumor visibility scores and overall mean technical validity and resulted in a comparable disease-free survival rate to LPN.

Recent developments in mesoporous polydopamine-derived nanoplatforms for cancer theranostics

Polydopamine (PDA), which is derived from marine mussels, has excellent potential in early diagnosis of diseases and targeted drug delivery owing to its good biocompatibility, biodegradability, and photothermal conversion. However, when used as a solid nanoparticle, the application of traditional PDA is restricted because of the low drug-loading and encapsulation efficiencies of hydrophobic drugs. Nevertheless, the emergence of mesoporous materials broaden our horizon. Mesoporous polydopamine (MPDA) has the characteristics of a porous structure, simple preparation process, low cost, high specific surface area, high light-to-heat conversion efficiency, and excellent biocompatibility, and therefore has gained considerable interest. This review provides an overview of the preparation methods and the latest applications of MPDA-based nanodrug delivery systems (chemotherapy combined with radiotherapy, photothermal therapy combined with chemotherapy, photothermal therapy combined with immunotherapy, photothermal therapy combined with photodynamic/chemodynamic therapy, and cancer theranostics). This review is expected to shed light on the multi-strategy antitumor therapy applications of MPDA-based nanodrug delivery systems.