Caroline J. Simon

Percutaneous Image-guided Thermal Ablation and Radiation Therapy: Outcomes of Combined Treatment for 41 Patients with Inoperable Stage I/II Non–Small-Cell Lung Cancer

PURPOSE To evaluate the clinical outcomes in patients with early-stage non-small-cell lung cancer (NSCLC) after combined treatment with thermal ablation and radiation therapy (RT). MATERIALS AND METHODS Forty-one patients with inoperable stage I/II NSCLC tumors underwent thermal ablation and RT at our institution between 1998 and 2005. Thirty-seven radiofrequency (RF) ablation procedures and four microwave ablation procedures were performed. Ablations were followed by standard-fraction external-beam RT within 90 days (n = 27) or postprocedural brachytherapy (n = 14). Survival and local recurrence were the primary endpoints evaluated by Kaplan-Meier analysis. RESULTS The median follow-up was 19.5 months. The overall survival rates were 97.6% at 6 months, 86.8% at 1 year, 70.4% at 2 years, and 57.1% at 3 years. Patients with tumors smaller than 3 cm (n = 17) had an average survival time of 44.4 +/- 5.4 months (SE). Patients with tumors 3 cm or larger (n = 24) had an average survival time of 34.6 +/- 7.0 months (P = .08). Local recurrence occurred in 11.8% of tumors smaller than 3 cm after an average of 45.6 +/- 4.1 months and in 33.3% of the larger tumors after an average of 34.0 +/- 7.8 months (P = .03). Outcomes in the brachytherapy and RT groups did not differ significantly. Nine of 15 pneumothoraces required chest tube drainage (22.0%). CONCLUSIONS Thermal ablation followed by RT for inoperable stage I/II NSCLC has a relatively low rate of complications that are easily managed. Combined therapy may result in an improved survival compared with either modality alone.

Hepatic tumor ablation with clustered microwave antennae: the US Phase II Trial

BACKGROUND Thermal ablation techniques have become important treatment options for patients with unresectable hepatic malignancies. Microwave ablation (MWA) is a new thermal ablative technique that uses electromagnetic energy to produce coagulation necrosis. We report outcomes from the first clinical trial in the United States using MWA and a 915 MHz generator. PATIENTS AND METHODS Patients with unresectable primary or metastatic liver cancer were enrolled in a multi-institutional trial from March 2004 through May 2006. Demographic information, diagnosis, treatment, and outcomes were documented. RESULTS Eighty-seven patients underwent 94 ablation procedures for 224 hepatic tumors. Forty-two ablations (45%) were performed open, 7 (7%) laparoscopically, and 45 (48%) percutaneously. The average tumor size was 3.6 cm (range 0.5-9.0 cm). Single antenna ablation volumes were 10.0 ml (range 7.8-14.0 ml), and clustered antennae ablation volumes were 50.5 ml (range 21.1-146.5 ml). Outcome variables were measured with a mean follow-up of 19 months. Local recurrence at the ablation site occurred in 6 (2.7%) tumors, and regional recurrence occurred in 37 (43%) patients. With a mean follow-up of 19 months, 41 (47%) patients were alive with no evidence of disease. There were no procedure-related deaths. The overall mortality rate was 2.3%. CONCLUSIONS Microwave ablation is a safe and effective technology for hepatic tumor ablation. In our study, clustered antennae resulted in larger ablation volumes. Further studies with histological confirmation are needed to verify clinical results.

Intraoperative Triple Antenna Hepatic Microwave Ablation

OBJECTIVE Microwave ablation is emerging as a new treatment option for patients with unresectable hepatic malignancies. This two-center study shows the results of a phase 1 clinical trial of patients with known hepatic masses who underwent synchronous triple antenna microwave ablation before elective hepatic resection. SUBJECTS AND METHODS Intraoperative microwave ablation was performed before hepatic resection. Hepatic lesions were targeted using real-time intraoperative sonography with three microwave antennas positioned in a triangular configuration. Microwave ablation was performed at 45 W for 10 minutes. Hepatic resection was then completed in the standard fashion. Gross specimens were sectioned and measured to determine tumor and ablation sizes. Representative areas were stained with H and E stain and vital histochemical nicotinamide adenine dinucleotide (NADH) stain. RESULTS Ten patients with a mean age of 64 years (range, 48-79 years) were treated. Tumor histology included colorectal carcinoma metastases and hepatocellular carcinoma. The mean maximal tumor diameter was 4.4 cm (range, 2.0-5.7 cm). The mean maximal ablation diameter was 5.5 cm (range, 5.0-6.5 cm), while the average ablation zone volume was 50.8 cm3 (range, 30.3-65.5 cm3). Gross and microscopic examinations of areas after microwave ablation showed clear coagulation necrosis, even surrounding large hepatic vessels (> 3 mm in diameter). A marked thermallike effect was observed with maximal intensity closest to the antenna sites. NADH staining confirmed the uniform absence of viable tumor in the ablation zone. CONCLUSION This study shows the feasibility of using multiple microwave antennas simultaneously in the treatment of liver tumors intraoperatively. Additional percutaneous studies are currently under way to investigate the safety and efficacy in treating nonsurgical candidates.

Image-guided percutaneous thermal ablation for the palliative treatment of chest wall masses

Objectives:To evaluate the palliative benefits of image-guided thermal ablation for the treatment of painful tumors affecting the chest wall. Methods:Thirty-nine patients, median age 65 years, underwent percutaneous thermal ablation of 44 chest wall masses. Thirty-eight radiofrequency ablations (RFAs), 3 microwave ablations (MWAs), and 3 cryoablations were performed. Subjective pain reports at 1 week and 1 month postablation were scored from 0 to 4 based on a standard Likert pain relief scale, with 2 or higher representing clinically significant pain relief. Results:Patients were followed for a median of 6 months. Overall, 31 of 44 procedures (70.5%) resulted in significant pain relief. Improvement followed 15 of 15 (100%) of ablations that were performed within 90 days of treatment with palliative external-beam radiation therapy (XRT), compared with 16 of 29 (55.2%) of the remaining procedures. Mean pain relief score at 1 month was 3.86 for the 15 combined procedures versus 1.96 for the 29 remaining procedures (P < 0.001). Local pain recurred after 5 of 31 positive responses (16.1%). Median survival was 11.2 ± 2.3 months for patients with significant pain relief and 4.3 ± 1.4 months for nonresponders (P < 0.001). Adverse events included a transient symptom “flare” (n = 5, 11.4%) and the exacerbation of a preexisting brachial plexopathy. Conclusions:Thermal ablation results in significant pain relief for the majority of patients and shows evidence of synergistic benefit when temporally combined with XRT. This minimally invasive technique appears to be a safe and durable alternative for the palliation of chest wall masses.

Current role of image-guided ablative therapies in lung cancer.

Lung cancer is the leading cause of cancer-related mortality in the USA. Until recently, lung cancer treatment options (dependent upon the tumor grading and staging at presentation, and patient comorbidities) included surgical resection (lobar or sublobar), chemotherapy and external-beam radiation therapy. While these options are still viewed as the primary standard of care, newer minimally invasive percutaneous ablative techniques such as radiofrequency ablation, microwave ablation and cryoablation are currently being examined as treatment alternatives, especially in the setting of the nonsurgical candidate. This review will focus on these three distinct thermoablative techniques in the percutaneous setting of lung cancer treatment.

Does failure to perform prophylactic level VI node dissection leave persistent disease detectable by ultrasonography in patients with low-risk papillary carcinoma of the thyroid?

BACKGROUND There is controversy regarding the need for prophylactic level VI central node dissection in patients with low-risk papillary thyroid carcinoma (PTC). This study focuses on the incidence of persistent level VI nodal disease in low-risk PTC without prophylactic central node dissection. METHODS PTC was known at the time of thyroidectomy in 304 of the 761 patients who had initial thyroid surgery from 2001 to 2007. Therapeutic level VI node dissection was performed for suspicious or positive nodes. A prophylactic central node dissection was not done if suspicious nodes were not identified. All patients had a high-resolution ultrasonography, and almost all patients had a suppressed serum thyroglobulin level 4-6 months after thyroidectomy. RESULTS A total of 112 of 304 patients (37%) had a therapeutic level VI node dissection. A prophylactic central node dissection was not performed in the remaining 192 patients. One hundred and sixty-one of the 192 patients (84%) were low risk. Biopsy-proven persistent disease was identified at the 4-6-month postoperative ultrasonography in only 3 of the 161 low-risk patients (1.8%). The suppressed serum thyroglobulin level was increased in these 3 patients and 2 additional patients. CONCLUSION Failure to perform a prophylactic central node dissection in low-risk PTC resulted in both a very low incidence of persistent level VI nodal disease and elevated suppressed thyroglobulin 4-6 months after thyroidectomy.

Evaluation of mulitprobe radiofrequency technology in a porcine model

OBJECTIVE We evaluated two new radiofrequency devices in an in vivo porcine model. MATERIALS AND METHODS Multiprobe radiofrequency ablation (RFA) was used in a porcine model with an impedance-based algorithm in one experiment and clustered probes with and without switcher controllers in another; a Pringle maneuver was used with half of the ablations. RESULTS The impedance experiment included 13 ablations, with a mean length of 7.0 cm and width of 2.9 cm (95% CI) and an average time of 596 s. Ablation volumes were significantly larger (54.1+/-11.7 cc(3) vs 34.9+/-4.8 cc(3), p<0.05) and ablation times were significantly shorter (359 s vs 834 s, p<0.05) for the Pringle group compared with the No Pringle group, respectively. The switcher controller experiment included 34 RFAs. Diameter (mm) (51.4 vs 40.3, p<0.0001), surface area (cm(2)) (22.4 vs 16.0, p<0.0002), and volume (cc) (66.1 vs 36.9, p<0.0001) were significantly larger for the combination probes with switcher controller compared with clustered probes, respectively. Ablation volumes for the Pringle vs No Pringle groups in the combination probes were 68.0 cc vs 64.3 cc and for the clustered probes 40.1 cc vs. 33.7 cc, respectively. CONCLUSION Multiprobe ablations using RFA are promising technologies that need further study to evaluate their clinical utility.