Cryoablation treatment of benign breast lesions with 12-month follow-up

OBJECTIVE: Eighty percent of all breast biopsies reveal benign findings. The most common benign tumor is a fibroadenoma. Despite their benign nature, many women eventually choose to have their bothersome lumps surgically removed. We report the use of cryoablation to treat these benign breast lesions with minimum 12-month follow-up. METHODS: After receiving Institutional Review Board approval, a prospective nonrandomized trial was initiated in June 2000. Ultrasound-guided cryoablation of core biopsy-proven benign fibroadenomas, other benign breast nodules, or nodular fibrocystic change was performed on 78 lesions in 63 patients. Eighty-five percent of lesions treated were benign fibroadenomas. The cryoablation procedure consisted of a double freeze-thaw cycle that lasted between 6 and 30 minutes and was performed most often in an office setting. Each patient was serially evaluated for treatment efficacy, complications, and patient satisfaction. RESULTS: Sixty-four of 78 lesions (mean size 2.0 cm [range 0.8 to 4.2]) were followed-up for at least 12 months after cryoablation per protocol, which included 53 fibroadenomas. At 1 year, ultrasound tumor volume resorption was 88.3% overall (87.3% for fibroadenomas), and 73% of the entire group became nonpalpable to both clinician and patient (75% for fibroadenomas). Two of the fibroadenoma patients had their palpable residual nodule excised, both revealing necrotic debris and no viable tumor in the treated volume. Serial mammograms showed resorption of the lesion leaving minimal residual density without calcifications. Cosmesis was excellent with only a small scar remaining at the probe insertion site. There was no report of visual or palpable volumetric deficit. Patient satisfaction was good to excellent in 92% of cases. CONCLUSIONS: Cryoablation was successful in treating core biopsy-proven benign breast lesions in 63 patients. At 12 months, we found gradual resorption of treated tissue with no cosmetic deficit. Ultrasound-guided cryoablation is an effective and safe treatment for benign breast lesions, as seen at 12-month follow-up, and offers an office-based, minimally invasive alternative to surgical excision.     

Cryoablation of benign breast tumors: evolution of technique and technology

We report on improvements in cryoprobe design and techniques of cryoablation as a minimally invasive alternative to open surgery for the treatment of benign breast tumors. In the study, which was conducted in 12 centers, 124 lesions in 102 patients were monitored for a period of 12 months after cryoablation. Two different treatment techniques were used: Double HI FREEZE and Tailored Freeze. In patients treated with the Tailored Freeze technique significantly better results were recorded 12 months after the procedure: the median reduction in tumor volume was 91%, 73% of all tumors treated were nonpalpable, 84% of lesions less than 2.5 cm in maximum diameter were nonpalpable, and none of the 31 mammograms performed yielded abnormal findings. Patient satisfaction was good to excellent in 92% of the patients. The safety profile of this technique was excellent; all complications were minor. Evolution of cryoablation freezing techniques, coupled with improvements in cryoprobe design, has resulted in significant improvements in both safety and effectiveness.     

Office-based cryoablation of breast fibroadenomas: 12-month followup

BACKGROUND: Fibroadenomas comprise between 30% and 50% of all breast biopsies. Despite their benign nature, many women have their fibroadenomas surgically removed. We previously reported on a minimally invasive therapy using cryoablation to treat fibroadenomas. We now report on 12-month followup using this technique. STUDY DESIGN: A prospective, nonrandomized trial was initiated in June 2000 with IRB approval. The Visica Treatment System was used to cryoablate 70 biopsy-proved fibroadenomas in 57 patients using a freeze-thaw-freeze cycle lasting 6 to 30 minutes. Each patient was serially evaluated for safety, efficacy, and satisfaction. RESULTS: Fifty-seven fibroadenomas (mean 2.1 cm, range 0.8 to 4.2 cm) in 47 patients were followed for 12 months. At 1 year, with 89% median tumor volume reduction measured by ultrasonography, 75% of fibroadenomas were nonpalpable. There were no adverse events and only minor complications. Two patients (4%) had their lesions excised after 12 months; pathology revealed no viable fibroadenoma. Serial mammograms showed resorption of the fibroadenoma leaving minimal residual density without calcifications. Cosmesis was excellent with no volume deficit, as no tissue is removed. Ninety-one percent of patients were satisfied at 12 months. CONCLUSIONS: Cryoablation is safe and effective in treating breast fibroadenomas. It offers a nonsurgical, office-based treatment that is well tolerated by patients and accurately monitored with ultrasonographic guidance. At 12 months we found progressive tumor volume reduction and reduced palpability, with no volume deficit, excellent cosmesis, and satisfied patients. Ultrasonography-guided cryoablation is a preferred option for treatment of breast fibroadenomas without open surgery.     

Office-based cryoablation of breast fibroadenomas with long-term follow-up

Approximately 10% of women will experience a breast fibroadenoma in their lifetime. Cryoablation is a new treatment that combines the better attributes of the current standards: surveillance and surgery. It is a minimally invasive office-based procedure that is administered without the use of general anesthesia, involving minimal patient discomfort and little to no scarring. This work aimed to establish the long-term (2-3 years) efficacy, safety, and satisfaction of the procedure, as well as the impact of cryoablation on mammogram and ultrasound images. Thirty-seven treated fibroadenomas were available for assessment with an average follow-up period of 2.6 years. Of the original 84% that were palpable prior to treatment, only 16% remained palpable to the patient as of this writing. Of those fibroadenomas that were initially < or = 2.0 cm in size, only 6% remained palpable. A median volume reduction of 99% was observed with ultrasound. Ninety-seven percent of patients and 100% of physicians were satisfied with the long-term treatment results. Mammograms and ultrasounds showed cryoablation produced no artifact that would adversely affect interpretation. Cryoablation for breast fibroadenomas has previously been reported as safe and effective both acutely and at the 1-year follow-up mark, and thus has been implemented as a treatment option. At long-term follow-up, cryoablation as a primary therapy for breast fibroadenomas demonstrates progressive resolution of the treated area, durable safety, and excellent patient and physician satisfaction. The treatment is performed in an office setting rather than an operating room, resulting in a cost-effective and patient-friendly procedure. Cryoablation should be considered a preferred option for those patients desiring definitive therapy for their fibroadenomas without surgical intervention.     

Progressive adoption of cryoablative therapy for breast fibroadenoma in community practice

BACKGROUND: Cryoablation is a recent technological advance and has been used for the percutaneous treatment of breast fibroadenomas. Herein, we provide a retrospective summary of the early experience from a nationwide group. METHODS: We organized a national registry to document the community practice and adoption of an office-based system of cryoablation for breast fibroadenoma. Data were abstracted during the first 6 weeks after the procedure to assess acute outcome and potential complications. At 6-and 12-month follow-up intervals, additional data were collected regarding fibroadenoma resolution, cosmesis, and patient satisfaction. RESULTS: Fifty-three sites ablated 310 fibroadenomas. Early follow-up data on 256 lesions showed that the procedure was well tolerated with infrequent minor complications immediately after the procedure. At 6 and 12 months postprocedure, the remaining fibroadenoma volume progressively involuted. At both intervals, cosmesis was excellent, and patient satisfaction was rated high. CONCLUSIONS: An early community experience with office-based cryoablation of breast fibroadenomas is encouraging and comparable to the initial experience of high-volume tertiary centers. More follow-up is necessary to determine long-term results and residual mammographic changes.     

Comparison of early and late dimensions and arrhythmogenicity of cryolesions in the normothermic canine heart

Little is known about myocardial cryoablation at normothermia and the effect of cryoprobe head size and duration of freeze on final lesion volume. In the present study, cryolesions were created with a carbon dioxide cryoprobe with two head sizes (cylindrical head 6 mm diameter and large circular head 18 mm diameter) in the normothermic canine heart during cardiopulmonary bypass. The duration of freeze (exposure time) varied from 2 to 3 or 4 minutes and the effects on immediate and chronic lesion size were evaluated. Lesions produced by epicardial exposures were compared with intramyocardial lesions created by placing the cylindrical head in a 6 mm stab incision. A minimum of four lesions were created in each dog. Lesion size was evaluated at 0 minutes (iceball) and 24 hours (two dogs), 7 days (one dog), or 4 weeks (five dogs). Iceball diameter was approximately 5 mm larger than chronic lesion diameter regardless of head size or exposure time. Prolongation of exposure time from 2 to 3 minutes resulted in significant increases in the volume of epicardial lesions (cylindrical head: 280 +/- 100 mm3 versus 740 +/- 200 mm3, p = 0.001; circular head: 1200 +/- 100 mm3 versus 2300 +/- 500 mm3, p = 0.007) because of increases in diameter and depth. No further increase in lesion size was observed when exposure time was prolonged from 3 to 4 minutes. A 3-minute intramyocardial exposure with the cylindrical head placed in a stab incision enabled production of transmural lesions (16 +/- 2 mm deep). Two and 4 weeks postoperatively, dogs underwent electrophysiologic study from the right and left ventricular apices. No animals had inducible ventricular tachycardia despite the heterogeneous configuration of the multiple cryolesions. In conclusion, it is possible to produce rapid and predictable ablation of clinically useful volumes of myocardium during normothermic bypass with the use of currently available equipment. Under these conditions, an exposure time of 3 minutes is optimal for a liquid carbon dioxide cryoprobe. Cryolesions should be overlapped by at least 2.5 mm to produce continuous areas of ablation. Multiple cryolesions do not form a chronic substrate for ventricular tachycardia.     

超声引导下Mammotome旋切术治疗乳腺纤维腺瘤40例

目的：探讨超声引导下Mammotome旋切手术对乳腺纤维腺瘤治疗的应用价值。方法：对乳腺纤维腺瘤患者分别进行超声引导下Mammotome旋切手术（40例）和传统的开放手术（57例）,比较分析其手术情况、并发症及随访结果。结果：Mammotome组切除肿瘤直径、切口长度以及多发肿瘤的切口数目明显小于开放手术组;手术时间、术中麻醉效果、术后并发症、肿瘤残余及复发两组无显著性差异,但对于临床无法触及的肿瘤及多发性肿瘤,Mammotome旋切手术时间比开放手术明显缩短;Mammotome组患者对乳房外形满意度明显高于开放手术组。结论：超声引导下Mammotome旋切治疗乳腺纤维腺瘤,具有定位准确、简便安全、美容效果突出的特点,尤其适于临床无法触及的隐匿性肿瘤和多发性肿瘤以及对形体有较高要求的患者。     

Percutaneous renal tumor cryoablation with magnetic resonance imaging guidance

PURPOSE: Cryoablation of small renal tumors has been performed mainly via the laparoscopic or open approach. This study was done to assess the feasibility and safety of performing percutaneous renal tumor cryoablation using interventional magnetic resonance imaging (MRI) for monitoring. MATERIALS AND METHODS: Patients with radiography documented small renal tumors 4 cm or less in diameter were offered percutaneous renal tumor cryoablation performed in an interventional MRI unit. Patients received general anesthesia or intravenous sedation and were placed into the interventional MRI unit. Under MRI guidance a 2 or 3 mm cryoprobe was advanced into the renal mass and the mass was subjected to 3 freeze-thaw cycles at -80 to 70C. Patients were hospitalized overnight for observation. Followup imaging with MRI or computerized tomography and physical examinations were done at 1 week, and 1, 3, 6 and 12 months. RESULTS: Ten men and 10 women 49 to 76 years old (mean age 58) with a total of 22 tumors have been treated, including 1 with bilateral lesions and another with 2 tumors in 1 kidney. Mean tumor diameter was 3 cm. (range 1.8 to 7.0). Two patients with a mass exceeding study entry criteria (5 and 7 cm, respectively) who were not open surgery candidates were treated on a compassionate basis. Average treatment time was 97 minutes (range 56 to 172). To date 1 patient has had evidence of persistent tumor on followup imaging and required re-treatment. The only complication was a superficial wound abscess. Mean followup was 9.1 months (range 3 to 14) with no radiographic evidence of disease recurrence or new tumor development. CONCLUSIONS: In this small series of patients percutaneous renal tumor cryoablation was technically feasible with minimal morbidity. At limited followup there appears to be no radiological evidence of new tumor development. Percutaneous cryoablation may prove to be an additional treatment option for small renal tumors.     

Percutaneous renal cryoablation of renal tumors in patients with von Hippel-Lindau disease

PURPOSE: We determine the feasibility and safety of performing percutaneous cryoablation of renal tumors in patients with von Hippel-Lindau disease. MATERIALS AND METHODS: We selected 2 men and 2 women with von Hippel-Lindau disease and radiographic determined solid renal tumors were selected to undergo percutaneous cryoablation. All patients underwent standard preoperative evaluation. An interventional magnetic resonance imaging unit was used for probe guidance and ice ball monitoring. The cryoablation procedure was performed with a 2 or 3 mm. cryoprobe using a pressurized argon gas system for ice ball formation. The patients were hospitalized overnight for observation and discharged home the following day. A followup computerized tomogram or magnetic resonance imaging scan was performed at 1 week, 1, 3, 6 and 12 months and every 6 months thereafter, along with physical examination, urinalysis, serum blood urea nitrogen and creatinine. RESULTS: A total of 5 tumors were treated ranging from 2.8 to 5.0 cm. in diameter. All patients underwent the procedure without difficulty with 2 requiring re-treatment due to residual tumor for a total of 7 treatments. At followup from 2 to 23 months there has been no radiographic evidence of recurrence at the cryoablated areas. CONCLUSIONS: Percutaneous cryoablation of renal tumors in patients with von Hippel-Lindau disease proved to be successful in this initial series. Although 2 patients had residual tumor after the initial cryoablation procedure re-treatment was performed with no adverse sequela. This minimally invasive therapy may allow patients with von Hippel-Lindau disease to avoid the necessity of multiple open surgical procedures.     

Interim results from the FibroAdenoma Cryoablation Treatment Registry

OBJECTIVE: The aim of this prospective study was to assess the intermediate- (6 months) and longer-term (12 months) follow-up of patients with breast fibroadenomas treated by cryoablation in community-based practice settings. METHODS: The FibroAdenoma Cryoablation Treatment (FACT) registry was created to systematically collect procedural and follow-up data for patients with fibroadenomas treated by cryoablation without subsequent excision. This report summarizes the experience from 55 different practice settings across the United States. Baseline and follow-up clinical data at 6 months and 12 months were tabulated for all patients. RESULTS: Data from 444 treated fibroadenomas were analyzed. The mean tumor diameter was 1.8 cm. Before cryoablation, 75% of fibroadenomas were palpable by the patient. Follow-up at 6- and 12-month intervals revealed palpability of the treated site in 46% and 35%, respectively. When fibroadenomas were grouped by size, for lesions 2 cm, residual cryoablation induce changes were visible by ultrasound in 39% of the patients at 6 months. The treatment area was palpable in 78% of the cases at the same time. Visibility by ultrasound was 32%, and palpability was 59% at 12 months follow-up. Patient satisfaction with the procedure was rated as high at 91% and 88% at 6 and 12 months follow-up, respectively. CONCLUSIONS: Before implementing this technique, patients should be apprised of the likely persistence of a palpable mass of the treated site for a prolonged period that will reabsorb over time. Palpability of the treated site persists for a substantially longer period of time for lesions greater than 2 cm in diameter. For patients with a fibroadenoma smaller than 2 cm, complete resolution can be expected in two thirds and three quarters of the patients at 6 and 12 months, respectively. We will continue to follow these patients to better define the length of time and factors influencing the resolution of the treatment induced physical and radiographic findings.     

Computer simulation of prostate cryoablation--fast and accurate approximation of the exact solution.

OBJECTIVE: Cryosurgery is a minimally invasive cancer treatment that uses liquid nitrogen or supercooled argon to freeze and destroy tumors. To achieve complete ablation of the prostate, we have developed a computer program that can determine treatment effects by calculating iceball formation. This is based on a three-dimensional (3D) model of the patient's prostate constructed from ultrasound images. The program predicts the best set of cryoablation parameters and cryoprobe spatial positions, then displays these parameters in graphical or numerical form. The objective of this work was to improve our prostate cryoablation modeling software by making its partial differential equation (PDE) solver more accurate and faster. MATERIALS AND METHODS: CryoSim, our software package, accepts a set of acquired and processed 3D ultrasound images of the prostate, then models heat diffusion using numerical approximations of the heat equation. RESULTS: We describe the latest version of the CryoSim software, which models cryoablation therapy. Solving the problems of low spatial resolution (now down to a fraction of a millimeter, as compared to 5 mm in the old version) and modeling cryosurgery in a short time (down to few minutes versus hours) provides a platform for proper planning of cryosurgery and a tool for the training of surgeons. CONCLUSION: Changes in the PDE solver algorithm produce more accurate results, leading to an improved visualization of the iceball, with a precision of a few mm and a significant decrease in computation time.     

腹腔镜治疗精囊良性肿瘤3例报告

目的:探讨腹腔镜手术治疗精囊良性肿瘤的效果。方法:2007年4月至2008年6月我院为3例患者行腹腔镜精囊良性肿瘤切除术。术前均经B超、CT及MRI等检查明确诊断,肿物大小40mm×30mm×25mm~63mm×45mm×40mm。结果:3例手术均成功切除精囊占位。手术时间64~120min,平均84min,术中失血60~120ml,平均74ml。术后平均随访11.3个月,未见局部复发及远处转移。结论:腹腔镜手术具有创伤小、并发症少、住院时间短等优点,是治疗精囊良性肿瘤的有效方法。     

MONITORING RENAL CRYOSURGERY: PREDICTORS OF TISSUE NECROSIS IN SWINE

Purpose

To examine parameters for monitoring renal cryosurgery and correlate with histopathologic necrosis in a porcine model. Parameters include: 1) tissue temperature, 2) distance of tissue from the cryosurgical probe insertion site, and 3) inclusion of tissue by the visible iceball.

Materials and Methods

Following midline incision, 6 healthy kidneys from 3 domestic pigs were treated using a nitrogen-based cryosurgical system with 3.4 mm outer diameter cryoprobe. Temperatures were monitored at 6 sites in each kidney using prototype thermocouples. Gross and histologic analysis was performed on tissue harvested from each thermosensor site 24 hours postoperatively.

Results

All animals survived to complete the full protocol. Post-procedure bleeding was managed surgically. Histopathology revealed that complete ablation was uniformly produced at temperatures of −19.4C or lower in 13/13 tissue samples. Within 16 mm. of the probe insertion site, cells were uniformly ablated in 17/17 samples while degree of tissue death varied widely beyond this margin. Cell death was more likely found at points encompassed by the visible iceball (16/18, 89%) than those beyond it (2/18, 11%) [p <0.0001, Chi-square] while 2/18 (11%) of samples harvested from within the iceball margin were partially viable.

Conclusions

Temperature monitoring using thermocouples during porcine renal cryosurgery demonstrated complete homogenous necrosis of tissues reaching −19.4C or lower. Distance beyond 16 mm. from the cryoprobe and direct visualization of the iceball proved to be less reliable predictors of tissue necrosis. Management of bleeding post-thaw was necessary in every case.     

氩氦刀冷冻消融治疗恶性肾肿瘤23例分析

目的探讨氩氦刀冷冻消融治疗恶性肾肿瘤的临床疗效。方法应用氩氦刀冷冻消融治疗恶性。肾肿瘤患者23例。CT引导下经皮肾穿刺9例,后腹腔镜下9例,开放手术5例。结果术后第1、6个月复查CT或MRI,肾肿瘤冷冻区域呈梗死、无信号增强、逐渐消散等演变过程。23例均未见出血、皮肤冻伤、感染、穿刺道种植转移等严重并发症。随访1．5～48个月,平均28．5个月。21例健康存活,未发现远处转移和复发;死亡2例。开放手术治疗者5例,其中左肾平滑肌肉瘤1例于术后1．5个月因肿瘤广泛转移死亡;CT引导下治疗患者,1例肿瘤直径为8cm者术后10个月因脑血管意外死亡。结论氩氦刀冷冻治疗恶性肾肿瘤技术可靠、创伤小、安全性高,是治疗孤立肾肾肿瘤或无法手术肾肿瘤的一种有效的新手段,对于小的肾肿瘤采用后腹腔镜下氩氦刀冷冻消融治疗是一种值得尝试的新方法。     

Effects of cryoablation on short-term development of urinary fistulas in the porcine kidney

PURPOSE: To determine the effect of cryoablation on the collecting system in the porcine kidney and the possible development of pelvic injury or fistula. MATERIALS AND METHODS: Six kidneys from three domestic swine were utilized. Under MRI guidance, a 3-mm cryoprobe was placed percutaneously and advanced to a point adjacent to the collecting system. The tissue then was frozen to -40 degrees C for 4 to 6 minutes to create a 2-cm iceball. At 1 week postprocedure, the kidneys were harvested and underwent gross and microscopic examination for evidence of fistula formation or renal pelvis injury. RESULTS: The procedures were performed without complications, although during placement of the probe in one pig, the collecting system was inadvertently entered. The diameter of the iceballs ranged from 2.0 to 2.5 cm. On pathologic examination, five of six of the kidneys, excluding the one noted above, were found to have no gross evidence of injury or fistula formation from the collecting system. Microscopic examination of the collecting system demonstrated necrosis extending up to the mucosa but no injury to the collecting system itself. CONCLUSIONS: In this animal model, no evidence of damage to the renal collecting system secondary to freezing was found. Treatment of renal tumors that are close to the collecting system may be possible without damage to the collecting system.     

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目的 总结原发性腹膜后肿瘤(primary retroperitoneal tumor,PRT)的诊疗方法.方法 回顾性分析东南大学附属徐州医院1995年6月至2005年6月收治的60例PRT病人的临床资料.结果 60例病人肿瘤直径(13.5±6.5)cm,均经手术治疗,且经病理证实.其中16例良性肿瘤完整切除14例(87.5%);42例恶性肿瘤完整切除28例(66.7%);2例间质细胞潜在恶性肿瘤行完整切除,恶性肿瘤切除后切缘予以氩氦刀消融术20例.良、恶性肿瘤3年存活率分别为88.3%和21.6%.结论 完整切除肿瘤是治疗的关键和影响预后的重要因素.氩氦刀冷冻切缘有助于获得肿瘤的阴性切缘,改善预后.PRT的预后与手术的彻底性和病理类型相关.影像学检查对诊断有重要意义.     

Acute and chronic interstitial cryotherapy of the adrenal gland as a treatment modality.

BACKGROUND AND OBJECTIVES: Adrenalectomy is indicated for patients with large adrenal lesions or functional tumors. Cryoablation is currently used as a surgical alternative for the treatment of prostate, lung, brain, pharynx, and liver tumors. The purpose of this study was to determine if cryosurgery could be delivered to small areas in the adrenal gland in a controllable and reproducible manner, so that tissue could heal in a nonpathological way. MATERIALS AND METHODS: Fourteen female mongrel dogs underwent acute (N = 8) or chronic (4 weeks) (N = 6) cryoablation using the Cryounit. In the acute study, using an open transabdominal approach, a 2-mm cryoprobe was placed interstitially into the adrenal tissue, while 0.032-inch thermocouples were cannulated into the ipsilateral adrenal artery and vein. Adrenal parenchymal temperature changes were measured using thermocouples placed at 0.4- and 0.8-cm intervals from the cryoprobe. In the chronic study, cryoablation was achieved by transperitoneal laparoscopic access using standard laparoscopic technique. RESULTS: Interstitial cryoprobe temperatures decreased from 33.1 +/- 1.9 degrees C to -148 +/- 1.2 degrees C following 15 minutes of freezing in the acute study. Cryoablation of adrenal tissue achieved temperatures of -41.8 +/- 5.7 degrees C and -21.8 +/- 1 degrees C at distances of 0.4 and 0.8 cm from the cryoprobe, respectively. There were no significant changes in adrenal artery or vein temperatures during cryoablation. Histologically, there was a clear demarcation between viable and nonviable tissue, the latter being characterized by areas of multifocal hemorrhage and pyknosis. After 4 weeks of healing, there was a well-defined line between necrotic and viable tissue. CONCLUSION: Cryoablation of the adrenal gland can be obtained in an effective, controllable, and reproducible manner. This controllable energy form may provide new modality for tissue destruction where adrenal gland preservation is necessary and can be delivered by the laparoscopic approach. Understanding the effect of adrenal cryoablation may allow us to treat selected patients with small tumors in whom organ preservation is necessary.     

PERCUTANEOUS CRYOABLATION OF PORCINE KIDNEYS WITH MAGNETIC RESONANCE IMAGING MONITORING

PURPOSE: We determined the feasibility of a percutaneous approach using magnetic resonance imaging (MRI) for creating cryoablation lesions in the porcine kidney. METHODS AND METHODS: Three domestic swine underwent renal cryoablation under MRI guidance with a total of 6 cryoablation lesions created in 5 kidneys. A 3 mm. cryoprobe was placed under MRI guidance using an interventional MRI unit. With a pressurized argon gas cooling unit the cryoablation lesion was created and monitored by MRI. Gross and histological examination of the kidneys was performed 1 week after the procedure. RESULTS: All animals survived the procedure without difficulty. A total of 6 cryoablation lesions were produced in 5 kidneys. The lesions were 1.9 x 1.3 to 3.9 x 1.9 cm. on MRI. Histological examination 1 week after treatment showed that the lesions were 1.7 x 1.0 to 3.2 x 1.2 cm. There was an area of coagulation necrosis surrounded by a transition zone of inflammatory reaction a mean of 0.5 cm. in diameter with each lesion. CONCLUSIONS: Percutaneous renal cryoablation using MRI imaging proved to be a successful technique for guiding probe placement and monitoring ice ball formation. Because MRI allows imaging in 3 planes, it may be useful for cryoablation of intraparenchymatous tumors.     

Needle-tract seeding after percutaneous cryoablation for lung metastasis of colorectal cancer

We report two cases of needle-tract seeding after percutaneous cryoablation for lung metastases of colorectal cancer. The targeted lung tumor was solitary in both cases. In patient 1, cryoablation was performed with a single cryoprobe, which was removed without freezing the cryoprobe tract. In patient 2, cryoablation was performed with two cryoprobes, both of which were removed after freezing of the cryoprobe tract. The seeding nodule appeared 5 and 7 months after cryoablation on the follow-up computed tomographic scan, respectively. In both cases, the seeding nodules were solitary and existed primarily in the subcutaneous to chest muscle layer, and could be completely resected under local anesthesia. Both lesions were pathologically confirmed as metastases from colorectal cancer. Local control was maintained in patient 1 for 4 years, until death due to progressive lung metastases. Patient 2 is alive without recurrences 8 months after resection.     

Use of Ultrasound-Guided Percutaneous Vacuum-Assisted Breast Biopsy for Selected Difficult Indications

Abstract:  To assess ultrasound-guided vacuum-assisted biopsy (US-VAB) for selected problem cases and to report experiences with two different biopsy systems. Fifty-one lesions have been biopsied using the Mammotome ( n  = 24) or the Vacora ( n  = 27) system. Main indications: lesion in scarring ( n  = 5), complex cystic ≥8 mm ( n  = 7), increase in size ( n  = 10), architectural distortion ( n  = 4), uncharacteristic palpable abnormality (2), small size ( n  = 22), regional microcalcifications ( n  = 1). Results are verified by surgical excision ( n  = 10) or follow-up ( n  = 40). One patient was lost to follow-up. In four of the cases preceding core biopsy was inconclusive. four invasive carcinomas, two ductal carcinoma in situ (DCIS), three papillomas, six fibroadenomas, one adenosis tumor, one hamartoma, 10 complex cysts, 16 benign changes, three fat necroses, two granulomas, three unspecific inflammatory changes are verified. Surgery confirmed five malignancies, four benign changes, and converted one uncertain diagnosis (architectural distortion) from "inflammatory" to DCIS. Documented removal of all or most of the lesions correctly increased the level of confidence and open surgery could be avoided in 41/51 lesions. The two systems show different advantages and drawbacks. US-VAB may improve the level of confidence in selected difficult cases. Careful case selection and systematic retrospective correlation of imaging and histology remain crucial.