Research presented at the Society of Interventional Radiology's (SIR) 32nd Annual Scientific Meeting shows that cryoablation is as effective as the laparoscopic technique in patients with renal cell carcinoma. The comparative trial shows that percutaneous cryoablation results in a slightly lower recurrence rate of the tumour, a shorter hospital stay, no major complications, and a 59.5% lower hospital cost than the laparoscopic treatment.
The study was presented by Dr J Louis Hinshaw, University of Wisconsin, and compared the outcomes of 19 percutanous and 48 laparoscopic cryoablations. The results showed that laparoscopic cryoablation had a slightly higher tumour recurrence rate (12.5% vs. 10.5%) than percutaneous cryoablation, percutaneous cryoablation required fewer days in the hospital (1.1 vs. 2.5), percutaneous cryoablation was more effective, with laparoscopic cryoablation costing 59.5% more than the percutaneous approach. Moreover, the interventional group had no major complications as opposed to the surgical group, which experienced complications in 6% of those studied (0% vs. 6.3%).
"This early stage research indicates that percutaneous cryoablation in the appropriate patient population can effectively kill tumours, while also offering patients a shorter hospital stay, a faster recovery, and an excellent safety profile, all at a lower cost than laparoscopy," noted Hinshaw. "Unfortunately, not all patients are viable candidates for percutaneous ablation and we work closely with our urology colleagues to ensure that each patient receives the most appropriate treatment.
"We are excited about this study because it offers patients with renal cell carcinoma a less traumatic treatment that can be repeated as needed," Hinshaw added. "Depending on the stage of the disease, this procedure can be curative, but can also be used for palliative treatment in some settings," he concluded.
RFA and osteoid osteoma
Also at the SIR meeting, Dr Eran Hayeems, University Health Network and Mount Sinai Hospital, Toronto, Ontario, Canada, presented data that highlighted the benefits of RFA when treating osteoid osteoma.
From September 2004 to July 2006, 27 CT-guided RFA procedures were performed on 26 patients (19M/7F) with symptomatic osteoid osteomas. Mean age was 29 years (17-62). Twenty-three of the patients had lower extremity or pelvic lesions, and three had upper extremity or scapular lesions. The procedure was technically successful in all the cases with no peri- or post-procedural complications. A total of 15 patients underwent general anesthesia, three had general anaesthesia combined with a nerve block and eight had epidural anaesthesia during their ablation procedures. A total of four different types of probes and generators were used in this experience. Clinical and imaging follow-up time ranged from one day to one year. Follow-up imaging was performed with gadolinium-enhanced MR imaging at one month post procedure.
The results revealed that 86% (19/22) of patients had clinical resolution of their pain post procedure. Three patients (14%) had no significant reduction in their pain post procedure. One of these patients elected to have a repeat RFA of her osteoid osteoma which resulted in immediate resolution of pain as well as no recurrence of symptoms at six months post procedure. In 88% (7/8) of patients who underwent gadolinium enhanced MR imaging at one month post procedure there was no evidence of enhancement of the nidus. All of these patients were symptom free at the time of their follow-up imaging. The patient who underwent a repeat procedure had evidence of enhancement of the nidus on the gadolinium-enhanced MR images following her first ablation procedure. The results showed that in 91% of those treated in the study, the treatment ended patients' pain immediately, with no post-procedure complications. Four patients were lost to follow-up.
"Our research showed the interventional treatment's success rate is as good as surgery's, but without the risk. Plus, almost all of our patients walked out of the hospital within hours of the procedure pain-free," said Hayeems, lead author of the study. "RFA is a safe and effective treatment for osteoid osteomas and follow-up imaging with gadolinium-enhanced MR imaging is a good predictor of symptomatic relief post ablation.
"Radiofrequency ablation allows otherwise healthy patients to avoid an invasive operation, get immediate pain relief, and get back to their lives right away," he added. "Because we can visualise the tumour, interventional radiology should be the first-line standard treatment for osteoid osteomas."
HACE
Finally, Dr J Ahrar, Anderson Cancer Center, Houston, TX, presented data on the response and survival rates of patients after receiving hepatic artery chemoembolisation (HACE) for patients with liver metastases from melanomas.
The medical records of all patients with melanomas metastatic to the liver who underwent HACE at the Anderson Cancer Center institution between 1992 and 2005 were reviewed. The researchers compared the follow-up cross-sectional imaging with the baseline imaging to determine the objective tumour response, graded according to World Health Organization criteria. Overall survival (OS) and progression-free survival (PFS) durations were calculated from the day of initial embolisation session using the Kaplan-Meier method.
During the study period, 181 patients (98 men and 83 women; mean age, 58 years) were treated with HACE (mean, 2.1 sessions; range, 1-8 sessions per patient) using Gelfoam or polyvinyl alcohol particles and cisplatin. Most patients had ocular (n=127) or cutaneous (n=45) melanomas. One patient had a rectal melanoma and the primary site was unknown in eight patients. A total of 119 patients (65.7%) had extrahepatic metastatic disease at the time of treatment and 95 patients (52%) had failed prior systemic chemotherapy.
Of the 152 patients in whom radiologic response could be evaluated, partial response (PR) was observed in 18 patients (11.9%), minimal response (MR) in 28 patients (18.4%), stable disease (SD) in 93 patients (61.2%), and progressive disease (PD) in 13 patients (8.5%). The median OS and PFS durations were 7.3 and 4.9 months, respectively. The response rates, and PFS and OS durations were not significantly different between patients with ocular primary and those with cutaneous primary. Patients who showed radiologic response (PR or MR) had longer OS (15.3 vs. 6.8 months; p<0.0001) durations than did patients who showed SD or PD.
The researchers concluded that hepatic arterial chemoembolisation can result in radiologic response or disease stabilisation in patients with ocular and cutaneous melanomas metastatic to the liver. Therefore, prolonged survival can be seen in patients who respond to HACE.
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