Ablation Of Masses Research Articles

Radiofrequency Ablation of Small Renal Masses.

Although the incidence of localized renal cell carcinoma has increased in recent decades due to greater use of imaging, the treatment has shifted to less invasive, nephron-sparing approaches. Radiofrequency ablation (RFA) is one accepted treatment modality for patients with small renal masses, and it has the advantage of being minimally invasive and highly nephron sparing, with the additional benefits of reduced blood loss and complication rates. We describe our experience with RFA with an accompanying instructional video outlining the procedure's key components.

Local anesthesia for percutaneous US/CT-guided bipolar radiofrequency ablation of small renal masses: A safe and feasible alternative

PurposeThis study is to evaluate the safety and feasibility of local anesthesia (LA) for percutaneous ultrasound/computed tomography (US/CT)-guided bipolar radiofrequency ablation (RFA) for small renal masses (SRMs) by comparing the LA with general anesthesia. Materials and MethodsA retrospective review was carried out between January 2018 to June 2020, 102 patients with SRMs were treated with US/CT-guided bipolar RFA. General anesthesia (GA) was performed in 42 and LA was performed in 60 patients. Demographics, tumor characteristics, peri-procedural data, pathologic and follow-up outcomes were analyzed. The factors associated with pain were also identified. ResultsThere was no significant difference in demographics and tumor characteristics between the LA and GA group. A statistically significant difference was observed in terms of procedural time (P = 0.010) and hospital stays (P < 0.001). The maximum perceived pain in LA group comprised 60.0% (36 of 60) mild, 40.0% (24 of 60) moderate. The anxiety in LA group comprised 65.0% (39 of 60) mild, 33.3% (20 of 60) moderate, 1.7% (1 of 60) severe. On multivariate analysis, tumor diameter was a significant predictor for pain in RFA procedure (OR 1.560, 95% CI 1.233–1.974, P < 0.001). All patients were followed up for a median (range) of 12 (2–24) months. Local recurrence occurred in 8.3% (5 of 60) of the LA group and in 7.1% (3 of 42) in GA group (P = 1.000). ConclusionPercutaneous bipolar RFA of SRMs using CT and ultrasound guidance under LA can be an effective and tolerable method for patients who are unfit for surgery and provide satisfactory oncologic control.

Real-time US/cone-beam CT fusion imaging for percutaneous ablation of small renal tumours: a technical note.

Fusion imaging is gaining attention as an imaging technique to assist minimally invasive tumour ablation. Ultrasound (US) and computed tomography (CT) are the most common imaging modalities to guide thermal ablation of renal tumours, yet cone-beam CT (CBCT) has recently been described to successfully assist percutaneous renal interventions. Our goal was to evaluate primary technical success and correct lesion targeting of US/CBCT fusion imaging to guide the ablation of kidney masses < 2 cm in a small group of patients. Six renal lesions (maximum diameter 11-17 mm) were treated with RFA in 5 different patients using real-time US/CBCT. Fusion imaging was used to identify and monitor tumour ablation. Demographics, tumour characteristics and mean serum creatinine levels were recorded before and after the procedure. Primary technical success and correct lesion targeting represented the main endpoints of the study. Primary technique efficacy was confirmed at 1-month and 3-month contrast-enhanced CT follow-ups. In all cases, a confident US/CBCT synchronisation was reached and allowed for a correct targeting and a successful percutaneous ablation. Primary technique efficacy was 100%. No recurrence was observed at the follow-up that ranged from 8 to 26 months (mean 16 months). US/CBCT fusion proved to be a viable method to precisely guide safe and effective percutaneous thermal ablation in patients with small renal tumours, especially when hardly detectable on US. • US/CBCT fusion imaging for renal ablation is safe and feasible. • US/CBCT fusion imaging allows for an improved targeting and complete ablation of small RCC with poor US-conspicuity.

Safety and oncological outcome following radiofrequency ablation of small renal masses in a single center

Objective To evaluate the safety and efficacy of percutaneous CT-guided radiofrequency ablation (RFA) for small renal masses (SRMs) at a large single-institution center during a period of 12 years. Materials and methods A total of 118 patients underwent RFA for SRM between July 2006 and July 2018 at our institution. We included demographic information, comorbidity, procedural details, and oncological outcome in the analysis. Survival analysis was performed using competing risk. Results 87 males and 31 females with median age 66 years underwent RFA. Median tumor size was 23 mm. Tumor biopsy was performed in 94% of cases, of which 56% were confirmed renal cell carcinoma (RCCs). Twenty-eight patients had benign tumors or underwent treatment for recurrence of prior RCC. Median follow-up of 5 years. Median Charlson Comorbidity Index was 5. Major complications occurred in 1.7%. No change in kidney function was observed. The initial treatment response was 98%. Among patients treated for newly diagnosed radiological suspected RCC without Von Hippel-Lindau or benign biopsy (90 pts), the cumulative incidence of radiological recurrence after 5 and 10 years was 6.6% (95% CI: 0.8–12%) and 16% (95% CI: 4.2–28%), respectively. Three patients died of RCC during follow-up. The cumulative incidence of kidney cancer death was 4.5% (95% CI: 4.3–13%) after 10 years. The incidence of other-cause mortality was 50% (95% CI: 34–67%). Conclusion CT-guided RFA is a safe and effective treatment option for patients unsuitable for surgery. RFA is a good alternative to partial or radical nephrectomy for SRMs, although randomized trials comparing surgery to minimally invasive thermal ablation techniques are missing.

Percutaneous microwave ablation of renal masses in a UK cohort.

To report a tertiary referral centre's experience of microwave ablation (MWA) for suspected renal cell carcinoma (RCC), describing complications and oncological outcomes. Consecutive MWA procedures (n=113) for renal masses (October 2016 to September 2019) were maintained on a prospective database. Data describing patient, disease, procedure, complications, and oncological outcomes were analysed. The median (range) age was 68 (33-85)years, 73% were male, and the median Charlson Comorbidity Index was 0. The median (interquartile range [IQR]) tumour diameter was 25(20-32)mm. In all, 95% had renal mass biopsy, with histologically confirmed cancer in 75%. The median (IQR) R.E.N.A.L. (Radius, Exophytic/Endophytic, Nearness, Anterior/Posterior, Location) nephrometry score was 7(6-8). The median ablation time was 6min and length of stay was 1day for 95% of the patients. Clavien-Dindo complication Grades I, II, IIIb and IV occurred in 18%, 1.8%, 0.9% and 0.9%, respectively. The median follow-up was 12months and the median (IQR) renal function change was -4(-18 to 0)%. One patient (0.9%) had local recurrence, treated with re-ablation; two developed metastatic progression; and two (1.8%) had indeterminate findings on follow-up (one lung nodule and one possible local recurrence), managed with ongoing protocolised computed tomography surveillance. Post-procedure complications were associated with total ablation time (odds ratio [OR] 1.152/min, 95% confidence interval [CI] 1.040-1.277) and total ablation energy (OR 1.017/kJ, 95% CI 1.001-1.033). We describe the largest UK series of MWA treatment for T1a/small T1b renal masses to date. MWA was well tolerated, with 95% discharged the following day and low complication/re-admission rates. Current follow-up demonstrates favourable disease control. MWA appears to be safe and effective and should be considered in future prospective comparisons of treatments for T1a/small T1b renal masses.

Long-term oncological outcomes for radiofrequency ablation of small renal masses

Objective: To describe oncology outcomes and complications with radiofrequency ablation (RFA) for T1 renal cell carcinoma in a centre with 14 years of experience. Method: Retrospective study of 95 consecutive patients from 2005 to 2013 who underwent RFA. Those with metastatic disease at time of treatment, incomplete follow up, proven benign pathology, genetic underlying genetic pre-disposition were excluded. 48 patients with 49 tumours met the inclusion criteria. Data was collected on demographics oncological outcomes and complications. Primary outcome measures were disease free survival and cancer specific survival at five and eight years. Results: Median follow up was 83 months. We demonstrate an 87% 5-year disease free survival (DFS) and 70% eight-year DFS. Mean time to progression was 45 months. Cancer specific survival was demonstrated as 97.9% at five years and 93.6% at eight years – all cancer-related deaths had an initial tumour of &gt; 3 cm diameter. 42.9% of the recurrences occurred beyond five years The median time to progression for secondary failure was 50.7 months. One Clavien-Dindo Grade 2 complication was encountered in the series. Outcome: RFA produces comparable long-term oncological outcomes to other modalities for T1 tumours with a low complication rate. Follow up should be considered beyond five years as a significant proportion of the recurrences (42.9%) in this study occurred beyond this point. Level of evidence: 4

Ablation of Small Renal Masses

Renal cell carcinoma is most commonly diagnosed in the sixth or seventh decade of life. Historically, surgical extirpation was the gold standard treatment option for small renal masses. However, given the comorbidities in this elderly population, not all patients are candidates for surgery. The development of minimally invasive ablative therapies has solved the surgical dilemma in this patient population. Furthermore, the 2017 American Urological Association guidelines recommends consideration of percutaneous image guided thermal ablation as a treatment option for masses smaller than 3 cm even in healthy individuals. Percutaneous image guided thermal ablation is an attractive treatment option providing excellent local tumor control, fewer complications, better preservation of the renal functions, faster recovery and shorter hospital stay. Various ablative modalities are available in clinical practice. This includes radiofrequency ablation, cryoablation, microwave ablation, irreversible electroporation, high intensity focused ultrasound, and laser ablation. In this review, we focus on the most commonly used modalities including radiofrequency ablation and cryoablation and to a lesser extent microwave ablation and irreversible electroporation.

Re: Utility of Intraprocedural Contrast-Enhanced CT in Ablation of Renal Masses.

Re: Utility of Intraprocedural Contrast-Enhanced CT in Ablation of Renal Masses.

Abstract No. 515 Renal tumor biopsy following percutaneous cryoablation of renal masses

Percutaneous tumor biopsy is recommended prior to percutaneous ablation of renal masses; however, reported complications of hemorrhage in up to 91% of cases in addition to probe crowding in small lesions may negatively affect mass visualization. Post biopsy track seeding is a rare, but biopsy of ablated tissue might decrease the probability. Tumor histology is readily identifiable after freezing. We report our experience of performing renal biopsy following percutaneous cryoablation of solid renal masses in order to assess the safety and feasibility of this technique. From December 2018 to July 2019, 8 patients with solid renal masses (1.6 to 2.2 cm) per contrast-enhanced MRI or CT concerning for malignancy underwent single session CT-guided percutaneous cryoablation and subsequent biopsy of ablated tissue. Cryoablation was performed under CT and ultrasound guidance. An iceball margin of > 5 mm was confirmed prior to thawing and probe removal. Core biopsy was subsequently performed with an 18-gauge coaxial needle of the visible mass within the treated volume. Samples were submitted to pathology in formalin and underwent routine processing. All patients were subsequently followed in clinic with repeat imaging every 3 months. There were no post procedure adverse events related to biopsy. Median follow-up for the cohort was 154 days (IQR 191 days). All ablated lesions demonstrated complete response per MRI and CT (2-7 months). Histologic diagnostic quality was adequate for all submitted specimens yielding renal cell carcinoma or oncocytoma in 6 and 2 patients, respectively (Table 1). Diagnostic core biopsy of renal masses immediately post cryoablation is both safe and feasible. Potential benefits of this approach should be validated in future studies.Table 1Renal Cell Carcinoma TypeGradeClear cell2Clear cell3PapillaryLowClear cell papillaryLowChromophobeLowChromophobe- Open table in a new tab

Abstract No. 514 Renal mass ablation in the octogenarian and nonagenarian population

To describe the outcomes of renal mass thermal ablation in the octogenarian and nonagenarian patient population. Our IRB-approved database of percutaneous renal ablations was retrospectively reviewed for patients greater than 80 years old undergoing renal mass ablation between February 2008 and August 2019. A total of 34 renal tumors were ablated in 19 males and 15 females with a mean age of 84.1 ± 3.1 years (range, 80-92 years). Procedural details and laboratory values were reviewed. A total of 10 renal microwave ablations and 24 cryoablations were performed. There were 27 T1a and 7 T1b renal tumors, overall tumor size ranged from 1.4-5.9 cm. Thirty-one ablations were performed as the primary intervention, and 3 were performed for tumor recurrence following partial nephrectomy (2) or prior ablation (1). The average number of probes was 3.3 in cryoablation and 2.7 in microwave ablation. Overall complication rate was 26%. There were three minor complications and five major complications, including two episodes of bleeding requiring red blood cell transfusion and one incidentally detected pseudoaneurysm in the ablation cavity of an asymptomatic patient which was subsequently embolized more than one year following the ablation. The mean pre procedure creatinine and eGFR was 1.20 and 50.9. The mean creatinine and eGFR post procedure was 1.23 and 49.3. Of the 25 patients with at least 3 months of CT or MR follow-up, there was no local recurrence and median follow-up was 23.7 months (range, 1.1-94.9 months). Concurrent biopsies were performed in 31 of the 34 cases. The pathology showed a majority of clear cell renal cell carcinoma (15), followed by oncocytic neoplasm (7), and papillary renal cell carcinoma (3). Four cases were nondiagnostic. The mean Charlson comorbidity index was 6.7. Mean renal nephrometry score was 6.3. Thermal ablation of renal masses in the elderly population is an effective treatment option with a low recurrence rate and without negative impact on renal function. The total complication rate in our cohort is high, but the total number of patients is small, and our reported experience ranges from our early use with percutaneous renal thermal ablation.

Renal Thermal Ablation Trends of American Urologists.

Objective: To define current trends in the utilization of renal thermal ablation by urologists in the United States. Material and Methods: A six-month case log data for renal procedures submitted by certifying and recertifying American urologists from 2003 to 2018 were obtained from the American Board of Urology and stratified by current procedural terminology code. The utilization of thermal ablative techniques was examined with respect to overall trends, surgeon, and practice characteristics associated with its use. Results: Six thousand two hundred eleven unique urologists performed 54,075 renal procedures, including 1916 (3.5%) thermal ablations, 630 (1.2%) renal biopsies, 17,361 (32.1%) partial nephrectomies, 20,403 (37.8%) radical nephrectomies, and 7957 (14.7%) nephroureterectomies. Eight hundred twenty-five (13.3%) unique urologists performed renal ablations, including 1344 (70.2%), 418 (21.8%), and 154 (8.0%) laparoscopic, percutaneous, and open ablation procedures, respectively. The annual volume of ablation was highest in 2008, followed by 2010 and 2009. On multivariate modeling of those performing renal interventions, the first decade of practice, self-declared endourologist, urologist who completed an endourology fellowship, urologist who practices in the Mid Atlantic, North Central, South Central, and South Eastern United States (compared with New England) were more likely to perform thermal ablation for renal masses. Urologists who perform renal biopsies and partial nephrectomies are also more likely to perform ablation of renal masses. Conclusions: Thermal ablation accounted for a small percentage of renal interventions performed by urologists in the last 1.5 decades with definable associations to practice characteristics. Renal ablation was most commonly performed laparoscopically, with declining use in recent years.

SC87 - Percutaneous radiofrequency ablation of small renal masses does not significantly reduce renal volume in hereditary renal cell tumour patients

SC87 - Percutaneous radiofrequency ablation of small renal masses does not significantly reduce renal volume in hereditary renal cell tumour patients

Imaging of Small Renal Masses before and after Thermal Ablation

Thermal ablation of small renal masses is increasingly accepted as an alternative to partial nephrectomy, particularly in patients with multiple comorbidities. Many professional societies support this alternate treatment with updated guidelines. Before performing thermal ablation, it is important to stratify risk and assess technical feasibility by evaluating tumor imaging features such as size, location, and centrality. Routine postablation imaging with CT or MRI is necessary for assessment of residual or recurrent tumor, evidence of complications, or new renal masses outside the ablation zone. The normal spectrum and evolution of findings at CT and MRI include a halo appearance of the ablation zone, ablation zone contraction, and ablation zone calcifications. Tumor recurrence frequently manifests at CT or MRI as new nodular enhancement at the periphery of an expanding ablation zone, although it is normal for the ablation zone to enlarge within the first few months. Recognizing early tumor recurrence is important, as small renal masses are often easily treated with repeat ablations. Potential complications of thermal ablation include vascular injury, urine leak, ureteral stricture, nerve injury, and bowel perforation. The risk of these complications may be related to tumor size and location.©RSNA, 2019.

Utility of Intraprocedural Contrast-Enhanced CT in Ablation of Renal Masses.

OBJECTIVE. The purpose of this study was to evaluate the efficacy of radiofrequency ablation (RFA) of renal masses comparing a group who did not undergo intraprocedural CT and a group who did. MATERIALS AND METHODS. A retrospective review included 45 consecutively registered patients who underwent RFA of renal masses. If an adequate biopsy specimen was not obtained or follow-up was inadequate, the patient was eliminated from review from calculation of primary technical efficacy. The inclusion criterion was having undergone RFA with two cooled-tip electrodes. Baseline demographics (age, body mass index, and sex), renal mass characteristics (diameter, side, location, position, morphologic features, type of mass, and grade), technical details (repositioning and hydrodissection), and complications were evaluated. Follow-up images were evaluated to determine the presence of recurrence at the ablation site in the two groups. RESULTS. Among the 45 patients who underwent RFA, 13 did not undergo intraprocedural CT and 32 intraprocedural did. Thirty-five patients met the criteria for follow-up and positive biopsy results. For calculation of recurrence, 10 patients were in the group who did not and 25 were in group who did undergo intraprocedural contrast-enhanced CT. No correlation was found between baseline demographics, renal mass characteristics, and technical results of the two groups. There was an 89% overall technical efficacy rate with a 96% primary technical efficacy rate in the group who underwent intraprocedural CT compared with a 70% rate in the group who did not undergo intraprocedural CT. Negative correlation was found between the groups with respect to technical efficacy rate at p < 0.05. CONCLUSION. Intraprocedural contrast-enhanced CT yields important information about completeness of ablation during the procedure, allowing probe repositioning and thus better therapeutic effect.

Prospective evaluation of CT-guided HDR brachytherapy as a local ablative treatment for renal masses: a single-arm pilot trial

In this pilot trial, we investigate the safety of CT-guided high-dose-rate brachytherapy (HDR-BT) as alocal ablative treatment for renal masses not eligible for resection or nephrectomy. We investigated renal function after irradiation by HDR-BT in 16patients (11male, 5female, mean age 76years) with 20renal lesions (renal cell carcinoma n = 18; renal metastases n = 2). Two patients had previous contralateral nephrectomy and two had ipsilateral partial nephrectomy. Six lesions had ahilar localization with proximity to the renal pelvis and would have not been favorable for thermal ablation. Renal function loss was determined within 1year after HDR-BT by renal scintigraphy and laboratory parameters. Further investigations included CT and MRI every 3months to observe procedural safety and local tumor control. Renal function tests were analyzed by Wilcoxon's signed rank test with Bonferroni-Holm correction of p-values. Survival and local tumor control underwent aKaplan-Meier estimation. Median follow-up was 22.5months. One patient required permanent hemodialysis 32months after repeated HDR-BT and contralateral radiofrequency ablation of multifocal renal cell carcinoma. No other patient developed asignificant worsening in global renal function and no gastrointestinal or urogenital side effects were observed. Only one patient died of renal tumor progression. Local control rate was 95% including repeated HDR-BT of two recurrences. HDR-BT is afeasible and safe technique for the local ablation of renal masses. AphaseII study is recruiting to evaluate the efficacy of this novel local ablative treatment in alarger study population.

Partial nephrectomy versus ablative techniques for small renal masses: a systematic review and network meta-analysis.

To compare partial nephrectomy (PN), radiofrequency ablation (RFA), cryoablation (CRA) and microwave ablation (MWA) regarding oncologic, perioperative and functional outcomes. The MEDLINE, EMBASE and COCHRANE libraries were searched for studies comparing PN, RFA, CRA or MWA and reporting on any-cause or cancer-specific mortality, local recurrence, complications or renal function. Network meta-analyses were performed. Forty-seven studies with 24,077 patients were included. Patients receiving RFA, CRA or MWA were older and had more comorbidities compared with PN. All-cause mortality was higher for CRA and RFA compared with PN (incidence rate ratio IRR = 2.58, IRR = 2.58, p < 0.001, respectively). No significant differences in cancer-specific mortality were evident. Local recurrence was higher for CRA, RFA and MWA compared with PN (IRR = 4.13, IRR = 1.79, IRR = 2.52, p < 0.05 respectively). A decline in renal function was less pronounced after RFA versus PN, CRA and MWA (mean difference in GFR MD = 6.49; MD = 5.82; MD = 10.89, p < 0.05 respectively). Higher overall survival and local control of PN compared with ablative therapies did not translate into significantly better cancer-specific mortality. Most studies carried a high risk of bias by selecting younger and healthier patients for PN, which may drive superior survival and local control. Physicians should be aware of the lack of high-quality evidence and the potential benefits of ablative techniques for certain patients, including a superior complication profile and renal function preservation. • Patients selected for ablation of small renal masses are older and have more comorbidities compared with those undergoing partial nephrectomy. • Partial nephrectomy yields lower all-cause mortality, which is probably biased by patient selection and does not translate into prolonged cancer-free survival. • The decline of renal function is smallest after radiofrequency ablation for small renal masses.

Infectious Outcomes from Renal Tumor Ablation: Prophylactic Antibiotics or Not?

Variability exists among institutions and physicians regarding the use of prophylactic antibiotics for ablation of renal tumors. The literature was reviewed for infectious complications vis-à-vis the reported use of prophylactic antibiotics for tumor ablation of renal neoplasms. PubMed was searched for articles reporting radiofrequency ablation, cryoablation, and microwave ablation of renal masses, both by percutaneous and laparoscopic approaches. Data regarding potentially infectious outcomes, prophylactic antibiotic use or not, patient information, lesion characteristics, and procedural specifics were extracted from relevant articles. Fifty-one articles met the inclusion criteria. Potentially infectious complications occurred in 74/6952 patients (1.06%) if fever is included, but only 29 patients (0.42%) if fever is excluded. Prophylactic antibiotics were reported in 373 patients and were not mentioned in 6579 patients. The incidence of fever was higher with the laparoscopic radiofrequency ablation and cryoablation compared to the percutaneous approach (p < 0.001). Prophylactic antibiotics seldom are used and/or reported in renal tumor ablation, and when they are, the antibiotic regimens vary widely. Even so, infectious complications in renal tumor ablation are uncommon. The similar and very low rates of infectious outcomes among ablation types and the two access approaches (laparoscopic and percutaneous) suggest that prophylactic antibiotics for routine renal tumor ablation are unnecessary.

Radiofrequency Ablation of Small Renal Masses: Outcomes, Complications and Effects on Renal Function

Introduction: To describe oncological outcomes, effects on renal function and complications with radiofrequency ablation (RFA) of T1 renal tumors in an 8-year experience. Materials and Methods: A retrospective study of RFA in 89 consecutive patients between 2005 and 2013 was undertaken. Those with metastatic disease, incomplete follow-up, genetic pre-disposition to renal tumors and biopsy proven benign pathology were excluded, with 79 patients meeting inclusion criteria. Data was collected on demographics, oncological outcomes, complications and effects on renal function. Results: We demonstrate 94% disease-free survival at median follow-up of 29 months in a population consisting of 42 T1a and 37 T1b tumors. No disease related deaths were recorded in the follow-up period. Post-RFA decline in renal function was shown to correlate with tumor size and increased age (p = 0.0009/0.0021). Pre-existing renal impairment was a risk for post-RFA function decline (p < 0.005). Two complications were encountered in the series. Conclusion: RFA produces durable oncological outcomes in T1 tumors with a minimal effect on renal function and low risk of complications. Patients at risk of developing renal impairment can be identified from described risk factors.

Radiofrequency ablation of small renal masses in comorbid patients.

IntroductionOver the recent years, the progress in imaging techniques has led to increased detection of small renal masses (SRMs), including in elderly and high-risk patients. Partial nephrectomy (nephron-sparing surgery – NSS), the current standard of care in T1a kidney tumours, has some limitations in patients who are poor candidates for surgery, as it is associated with potential perioperative complications and possible renal function loss. Radiofrequency ablation (RFA), a minimally invasive method that can be performed percutaneously, is an option in such cases.AimTo present our experience in treatment of SRMs using RFA in comorbid patients.Material and methodsIn the years 2006–2012, 103 percutaneous, ultrasound-guided RFA procedures were performed in the Oncology Centre in Bydgoszcz in patients with an ASA score ≥ 3. Abdominal computed tomography and tumour biopsy were performed before the procedure. The average follow-up time was 46 months.ResultsThe 1, 3 and 5-year overall survival rates were respectively 97%, 90% and 75%, while cancer-specific survival was 100%. No Clavien-Dindo grade ≥ 3 complications were observed.ConclusionsRadiofrequency ablation performed percutaneously is a minimally invasive treatment and may be applied in patients who are, due to comorbidities, poor candidates for surgery. In comorbid patients, where other causes of death play an important role, the application of a minimally invasive treatment method with satisfactory oncological effectiveness is justified.

3:09 PM Abstract No. 333 Treatment approach for percutaneous ablation of metastatic adrenal masses

The adrenal gland is a common site of metastasis. Palliative ablation can have a role in tumor debulking for symptom management or offer an alternative to adrenalectomy for poor surgical candidates. The position of the adrenal in the retroperitoneum often requires access across the diaphragm or adjacent organs. This report describes our experience with percutaneous image-guided ablation of adrenal masses and approach for tumor access. HiIQ database was reviewed for cases of adrenal ablation performed August 2002 - August 2017. 19 ablations were performed under CT guidance in 12 patients (7 male, median age 61), of which 11/19 (58%) were right-sided. Cases were reviewed for tumor size, etiology, ablation modality, ablation approach, and complications. Etiologies were lung cancer (7), hepatocellular carcinoma (3), renal cell carcinoma (1), and neuroendocrine tumor (1). Mean adrenal size was 4.4 ± 2.5 cm. Ten of 19 cases (53%) used cryoablation (CA), 3/19 (16%) microwave ablation (MW) and 6/19 (32%) radiofrequency ablation (RF). Mean number of ablation sessions per lesion was 1.3 ± 0.5. Median number of probes was 3 for CA and 1 for RF and MW. Half of CA procedures were performed with conscious sedation. Only 3 cases allowed a direct approach. Alternative approaches included transpleural alone (11/19; 58%) or combination transpleural and transhepatic/transplenic (5/19; 26%). One CA procedure was aborted due to patient syncope, resulting in incomplete ablation. There was one minor complication of self-limited asymptomatic right pneumothorax. Percutaneous image-guided adrenal mass ablation is technically feasible with a low rate of complications. The location of the adrenal gland makes direct access often unfeasible; however, alternate approaches can provide safe treatment windows.