|ECR 2014 / B-0883|
|Patient outcome after pulmonary radiofrequency ablation: a prospective analysis of results from a single centre|
|This poster is published under an open license. Please read the disclaimer for further details.|
Pulmonary RFA is a safe and well-tolerated technique. Compared with surgical resection RFA is less invasive and may be performed under conscious sedation, either as a day case or with a single night in hospital, with negligible effect on the patient’s lung function. When selecting patients for surgical metastatectomy performance status and poor lung function can preclude some patients from surgical treatment (2), whereas this is less likely to preclude patients from treatment with RFA.
The 3-year survival from our data was 77.7% for pulmonary metastases. This compares well with recently published data, which suggested that RFA could provide survival benefit. Gillams et al reported a 3-year survival of 57% in 122 patients (3). Other comparable studies reported a 46% 3 year survival in 55 patients (4), and 47% in 71 patients (5).
The main factors affecting survival were the total number of lesions treated, which came close to reaching statistical significance. Where the total number of lesions treated is 3 or more, then the overall survival is likely to be reduced.
We found no significant relationship between tumour size at the time of RFA and survival. This contrasts with published data, as other groups have found size to be a dominant factor affecting survival. Gillams et al (3) showed that lesions 2 cm or less demonstrated a trend toward better survival than tumours 2.1 cm to 4 cm in size. The majority of lesions treated at our centre were less than 15mm in diameter, and our local practice of treating lesions earlier, when smaller, may account for the apparent lack of a relationship between size and outcome shown in our results. The need for a clear ablation margin parallels that seen in surgical resections. The larger the tumour, the more difficult this is to obtain without multiple overlapping ablation zones. Complete ablation with this adequate margin becomes increasing difficult to ensure with increasing lesion size. For this reason most centres will accept a tumour size, beyond which ablation is likely to be incomplete. This is usually around 3-3.5cm in diameter.
Close proximity to segmental pulmonary or mediastinal vessels was the main risk factor for recurrence. Although not an absolute contra-indication to RFA, it is a significant contributor towards under-treatment.
Our 3-year survival of 77.7% compares favourably with surgical resection (6, 7, 8), suggesting that RFA is equivalent to resection in resectable disease.
The number of lesions ablated at the initial attempt does not appear to impact on survival. It is generally accepted from prior surgical series that surgical resection be limited to those candidates with 3 or fewer tumours (9, 10, 111) to prevent increased morbidity and mortality. This reinforces the usefulness of RFA as an alternative to surgery, as it can be used effectively in treating multiple lesions at the initial attempt while allowing easier re-treatment of recurring lesions.
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