Diagnostic accuracy of 18F-FDG PET/CT for assessing response to radiofrequency ablation treatment in lung metastases: a multicentre prospective study

Abstract

The specificity of PET/CT at 3 months is low because of persistent inflammation, especially when the lesion is close to the pleura. This technique is useful for its negative predictive value, but positive findings need to be confirmed by histology before new treatment is planned.

Percutaneous radiofrequency ablation for patients with malignant lung tumors: a phase II prospective multicenter study (JIVROSG-0702)

“…Deandreis et al reported that FDG-PET could detect LTP at the treatment site with more sensitivity than conventional CT [16]. On the other hand, Bonichon et al reported low specificity and a high false-positive rate using evaluation with FDG-PET/CT 3 months after RF ablation [15]. The authors also asserted that FDG-PET/CT was useful for its negative predictive value.…”

“…The primary endpoint of the current study was thus determined as described in these prior reports. Several clinical trials conducted more recently have evaluated the utility of FDG-PET as an evaluation method for RF ablation of lung tumors [11,15]. Deandreis et al reported that FDG-PET could detect LTP at the treatment site with more sensitivity than conventional CT [16].…”

Thermal Ablation of Lung Tumors: Focus on Microwave Ablation

“…moderate to high 18 F-FDG uptake might persist. However, this does not indicate progression on follow-up in the majority of cases [68]. As the ablation zone undergoes fibrous transformation and shrinks, the ring-like uptake pattern that can still be present at 6 months will be replaced by a nodular pattern.…”

“…5) [66]. Three months after treatment, 57 -68 % of the ablation zones will show no or mild 18 F-FDG uptake which has a high negative predictive value [67,68]. In the remaining cases, a ▶ Fig.…”

“…Local progression should be considered when a new high-uptake focus is detected within or at the periphery of the ablation zone after a period of decreased activity. An active region does not necessarily represent tumoral tissue, especially in the first three months after ablation [61,68,69]. Additional ablation should be considered by taking more factors into account, such as an increased size of the ablation zone, and the new occurrence of periablational nodularity or contrast enhancement patterns (▶ Fig.…”