Radiofrequency Ablation of Renal Tumors

Abstract

Radiofrequency ablation (RFA) of renal tumors is a promising technique that plays a unique and increasingly important role in urologic oncology practices. RFA is appealing as a minimally invasive therapy that may be performed on an outpatient basis. It enables treatment of an area 3 to 5 cm in diameter, with relatively low morbidity and mortality rates. Most interventional radiologists (IRs) are familiar with RFA of liver tumors, and several principles and techniques used in the liver may be extrapolated for use in the kidney. However, it is crucial to bear in mind that local tumor ablation in the kidney presents unique challenges, secondary to the kidney's unique anatomic and physiologic features. Clinical and technical considerations, risks, and complications pertaining to RFA of renal tumors are reviewed here, including approaches commonly used in our practice. Keywords radiofrequency ablation; kidney; renal cell carcinoma; Von Hippel-Lindau syndrome Renal cell carcinoma (RCC) continues to be a significant source of morbidity and mortality despite advances in minimally invasive surgical and percutaneous options. RCC accounts for approximately 85% of renal tumors. 1,2 Most interventional radiologists (IRs) are familiar with radiofrequency ablation (RFA) of liver tumors, but local tumor ablation in the kidney presents unique challenges.Recently, renal tumor RFA has become an invaluable tool for the IR. Initially, RFA of renal tumors began in patients who were nonoperative candidates since the "gold standard" treatment for RCC of any size had historically been radical nephrectomy. With the advent of nephron sparing surgery, renal tumor removal with prevention of the surrounding kidney is now often the first choice in RCC management. Some would argue that this should no longer be the case, as RFA has proven to be a benefit in patients with a history of prior nephrectomy or solitary kidney, hereditary or familial renal cancer, and baseline renal insufficiency. In addition, nonstandard indications for renal RFA have been described and now include transfusionAddress reprint requests to: Bradford J. Wood, MD, Diagnostic RadiologyDepartment,

Percutaneous Ablation of Adrenal Tumors

“…In most instances, ultrasound, CT or a combination of ultrasound and CT is used for imaging guidance during ablation. As has been described for renal ablation, communication with the anesthesiologist to coordinate breathing can also help avoid transgression of the pleura and enable movement of a target lesion off of an intervening rib 65. Prior to needle insertion, hydrodissection may be employed for further protection of surrounding tissues when thermal ablation is being performed with RFA, cryoablation or microwave ablation.…”

“…These include initial probe insertion into tumor, application of thermal energy, probe repositioning within tumor, probe removal, probe torquing, and additional treatments. As is true for ablation in other organs, increasing the anesthetic dose immediately prior to the onset of ablation can facilitate the optimal combination of patient comfort and safety 65. As the published literature warns, the operator must be aware of the risk for hypertensive crisis in all patients undergoing adrenal thermal ablation.…”

“…As the published literature warns, the operator must be aware of the risk for hypertensive crisis in all patients undergoing adrenal thermal ablation. Damage to the adrenal gland can also result in adrenal insufficiency in certain patient populations, typically those with a history of prior nephrectomy with unilateral adrenalectomy 65. The need for central line placement and radial arterial catheter pressure monitoring during ablation, and the duration of inpatient post-procedure hemodynamic monitoring or ICU admission should be made on a case by case basis after careful individual evaluation.…”

Parametric study of radiofrequency ablation in the clinical practice with the use of two-compartment numerical models

“…RFA is mainly used for the treatment of hepatocellular carcinoma (Lau & Lai, 2009;Lencioni & Crocetti, 2007), in renal cell carcinoma (Hoffmann, Jakobs, Trumm, Helmberger, & Reiser, 2008;Park & Cadeddu, 2007;Stone et al, 2007), in non-small cell lung cancer (Zhu, Yan, & Morris, 2008) and in osseous metastases for the palliation of pain (Hoffmann et al, 2009;Thanos et al, 2008). There have been many studies on the computational modeling of RFA in human tissues, mainly in liver, investigating either a one-compartment model, where tumor and tissue have the same electrical and thermal properties, or a two-or multi-compartment model, which apply different properties in human tissue and tumor (Ahmed, Liu, Humphries, & Goldberg, 2008;Chang, 2010;Liu et al, 2005;Pop et al, 2003).…”

Radijo dažnio abliacija ankstyvuoju poprocedūriniu laikotarpiu skatina inkstų audinio apoptozę

“…The main complications of this procedure are the thermal injuries of surrounding organs and tissues such as ureters, surrounding bowel, genitofemoral and ilioinguinal nerves, psoas muscle, adrenal gland and diaphragm. Retroperitoneal hematomas and damage of renal collective system also can occur [7].…”