Loukas Thanos

Percutaneous microwave ablation vs radiofrequency ablation in the treatment of hepatocellular carcinoma

Hepatocellular cancer ranks fifth among cancers and is related to chronic viral hepatitis, alcohol abuse, steatohepatitis and liver autoimmunity. Surgical resection and orthotopic liver transplantation have curative potential, but fewer than 20% of patients are suitable candidates. Interventional treatments are offered to the vast majority of patients. Radiofrequency (RFA) and microwave ablation (MWA) are among the therapeutic modalities, with similar indications which include the presence of up to three lesions, smaller than 3 cm in size, and the absence of extrahepatic disease. The therapeutic effect of both methods relies on thermal injury, but MWA uses an electromagnetic field as opposed to electrical current used in RFA. Unlike MWA, the effect of RFA is partially limited by the heat-sink effect and increased impedance of the ablated tissue. Compared with RFA, MWA attains a more predictable ablation zone, permits simultaneous treatment of multiple lesions, and achieves larger coagulation volumes in a shorter procedural time. Major complications of both methods are comparable and infrequent (approximately 2%-3%), and they include haemorrhage, infection/abscess, visceral organ injury, liver failure, and pneumothorax. RFA may incur the additional complication of skin burns. Nevertheless, there is no compelling evidence for differences in clinical outcomes, including local recurrence rates and survival.

Unifying the predictive value of pretransplant FDG PET in patients with lymphoma: a review and meta-analysis of published trials

PurposeThe predictive value of 18F-FDG PET in patients with relapsing/refractory lymphoma who are receiving high-dose chemotherapy and autologous stem cell transplantation (ASCT) remains a matter of debate. Seminal reports on pretransplant ASCT indicated an adverse prognosis in patients with positive FDG PET scans. The lack of a uniform outcome measure along with the mixed histologies in various studies have hampered efforts to quantify this prognostic value.MethodsA MEDLINE review of published trials up to April 2009 identified 16 studies involving pretransplant FDG PET scans in lymphoma. Where progression-free survival (PFS) and overall survival (OS) were set as the main outcome measures, time-to-event data analysis was used to calculate the overall prognostic value of a pretransplant FDG-PET scan.ResultsPooled survival data from seven eligible studies suggested a worse PFS in patients with a positive FDG PET study (HR 3.23, 95% CI 2.14 to 4.87). The OS pooled from six eligible studies was also significantly worse among patients with a positive FDG PET study (HR 4.53, 95% CI 2.50 to 8.22). No statistically significant heterogeneity was observed between studies for either outcome.ConclusionDespite the documented clinical heterogeneity between studies, meta-analysis data confirmed the prognostic impact of pretransplant FDG PET in patients with lymphoma and provided a uniform measure of the association for both progression and survival after ASCT.

Percutaneous radiofrequency ablation of renal cell carcinomas in patients with solitary kidney: 6 years experience

OBJECTIVE In this study we attempt to present our clinical experience in RFA under CT-guidance, in patients with renal cell carcinoma in a solitary kidney. MATERIAL AND METHOD Between October 2000 and June 2005, 18 patients with solitary kidney and renal cell carcinoma underwent percutaneous CT-guided radiofrequency ablation in our institution. Tumors diameter ranged from 1 to 7 cm and there was no evidence of spread beyond the kidney. The RFA-system used was with expandable needle electrode (7 or 9 arrays). Technical success, recurrence and survival rate and complications were accessed. Patients were available for clinical and laboratory evaluation at a mean follow-up time of 31.2 months (range: 12-72 months). RESULTS In all cases the electrode was successfully placed at the lesion. The 18 tumors were treated with totally 24 RFA sessions. In small (1-3 cm) exophytic tumors technical success was 85.7%. Residual disease was totally seen in 6/18 tumors which required a 2nd RFA session. The recurrence rate was 11.1% but no recurrence was noticed in tumors less than 3 cm in diameter. No major complications were observed. Serum creatinine values were normal in 17/18 patients till the 3rd-month follow-up. Survival ranged from 12 to 72 months. CONCLUSION RFA is an acceptable alternative for patients with small RCCs in a solitary kidney, which are not ideal candidates for surgical resection as their renal function must be preserved. They have an immediate solution to their clinical problem, under a minimally invasive therapy with no serious complications.

Nodular hepatic and splenic sarcoidosis in a patient with normal chest radiograph.

Almost all the patients with sarcoidosis have an abnormal chest radiograph, while nodular lesions of both the liver and the spleen is an unusual manifestation of abdominal sarcoidosis. We report a case of a patient with numerous hypodense nodular hepato-splenic lesions on abdominal CT and a normal chest X-ray. Biopsy of an hepatic lesion revealed sarcoidosis.

CT-Guided Fiducial Placement for CyberKnife Stereotactic Radiosurgery: An Initial Experience

CyberKnife frameless image-guided radiosurgery has become a widely used system for parenchymal extracranial lesions. Gold fiducials are required for the planning and aiming of CyberKnife therapy. We report our initial experience and describe the technique of positioning tumor markers, under CT guidance. We conducted a retrospective review of 105 patients who were referred for CyberKnife stereotactic radiosurgery at Iatropolis CyberKnife Center in Athens. All patients underwent percutaneous fiducial placement via CT guidance. At the desired location, the 18-G needle was advanced into or near the tumor. Data collected included number and locations of fiducials placed and complications experienced to date. One hundred five patients underwent fiducial placement under CT guidance and a total number of 319 gold seeds were implanted. We experienced one episode of pneumothorax that required drainage, one mild pneumothorax, and three episodes of perifocal pulmonary hemorrhage. In conclusion, fiducial implantation under CT guidance appears to be a safe and efficient procedure, as long as it is performed by an experienced interventional radiologist.

An unusual case of brucellar spondylitis involving both the cervical and lumbar spine

We report an unusual case of brucellar spondylitis, involving both the cervical and lumbar spine. Diagnosis was established using magnetic resonance imaging (MRI). An initial plain radiograph of the lumbar spine, showing mild degenerative lesions, was misleading. Therefore, institution of a proper treatment was delayed.

Radiofrequency ablation of subcapsular hepatocellular carcinoma: single center experience.

PURPOSE To present a single center results, regarding radiofrequency ablation (RFA) of subcapsular hepatocellular carcinoma (HCC). MATERIALS AND METHODS Forty patients with subcapsular HCC were treated with RFA under CT guidance for fifty-two discrete lesions in our institution. Twenty-eight patients underwent ablation of a solitary tumor and twelve patients underwent RFA of two tumors. Six patients had a subcapsular HCC with an exofitic location. All lesions had a diameter of <4 cm. We used two types of generators and electrodes: spiral electrode and expandable electrode. Needle track ablation was performed in all cases. Follow-up consisted of an abdomen computed tomography (CT) scan after contrast administration immediately after each session and then after one, three, six, and twelve months. RESULTS In forty-eight lesions complete tumor ablation was depicted at the one month CT scan. In four lesions with residual viable tumor, a second session was performed. After the second ablation no residual tumor was observed in any patient. No major complications occurred in any of our patients. Fever with a temperature up to 39 °C was documented during the first days as part of the post-ablation syndrome in thirteen patients (32.2%). Seeding along the needle track was observed in none of our patients. Local tumor progression, was observed in ten lesions (19.25%) and in all cases a second RFA session was performed with optimal results. CONCLUSION Subcapsular location should not be considered as a contraindication for liver RFA.

Aorto-enteric fistula: CT findings

The objective of this pictorial essay is to present the different CT findings encountered in patients with aorto-enteric fistulas (AEFs). An AEF is a rare and sometimes disastrous occurrence, responsible for intermittent or massive gastrointestinal hemorrhage and hematemesis. CT provides fast and effective evaluation in hemodynamically stable patients suspected of having an AEF.

Sternal tuberculosis after coronary artery bypass graft surgery.

We report a case of sternal tuberculosis following sternotomy, which was performed during coronary artery bypass graft surgery. Although pre-operative evaluation revealed signs of asymptomatic tuberculosis of the lung, isoniazid chemoprophylaxis was not instituted, and the patient developed active tuberculosis in both the lung and sternum 5 y later.We report a case of sternal tuberculosis following sternotomy, which was performed during coronary artery bypass graft surgery. Although pre-operative evaluation revealed signs of asymptomatic tuberculosis of the lung, isoniazid chemoprophylaxis was not instituted, and the patient developed active tuberculosis in both the lung and sternum 5 y later.

Percutaneous radiofrequency thermal ablation in the management of lung tumors: presentation of clinical experience on a series of 35 patients.

PURPOSE To present our results in a series of 35 patients with malignant pulmonary lesions, who underwent radiofrequency thermal ablation (RFA) during a period of 18 months. MATERIALS AND METHODS In our institution, 55 RFA sessions under computed tomography (CT) guidance were performed on 48 pulmonary malignant lesions (23 inoperable primary and 25 metastatic) in 35 patients. RESULTS Total necrosis was noted in 19 primary (82.6%) and in 19 metastatic lesions (76%). In four primary (17.4%) and in six metastatic lesions (14%), partial necrosis was achieved, and a second RFA session was performed. The 6-month spiral CT follow-up demonstrated recurrence in seven lesions (14.5%) (four primary and three metastatic), which were treated with an additional RFA session. Two of the patients who underwent the procedure died of disseminated disease after one year, accounting for a 1-year survival rate of 94.2%. Mean survival was 14.48 +/- 3.3 months. CONCLUSION RFA is an effective method for treating unresectable lung carcinoma and lung metastases.