Department of Surgery, VU University Medical Centre, Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.
Eur J Radiol. 2013 Dec;82(12):2169-75. doi: 10.1016/j.ejrad.2013.08.024. Epub 2013 Aug 23.
The main area of concern regarding radiofrequency ablation (RFA) of colorectal liver metastases is the risk of developing a local site recurrence (LSR). Reported accuracy of PET-CT in detecting LSR is high compared to morphological imaging alone, but no internationally accepted criteria for image interpretation have been defined. Our aim was to assess criteria for FDG PET-CT image interpretation following RFA, and to define a timetable for follow-up detection of LSR.
Patients who underwent RFA for colorectal liver metastases between 2005 and 2011, with FDG-PET follow-up within one year after treatment were included. Results of repeat FDG-PET scans were evaluated until a LSR was diagnosed. Results. One hundred-seventy scans were obtained for 79 patients (179 lesions), 57 scans (72%) were obtained within 6 months of treatment. Thirty patients developed local recurrence; 29 (97%) within 1 year. Only 2% of lesions of <1cm and 4% of <2 cm showed a LSR.
The majority of local site recurrences are diagnosed within one year after RFA. Regular follow-up using FDG PET-CT within this period is advised, so repeated treatment can be initiated. Rim-shaped uptake may be present until 4-6 months, complicating evaluation. The benefit in the follow-up of lesions <2 cm may be limited.
射频消融（RFA）治疗结直肠癌肝转移的主要关注点是局部复发（LSR）的风险。与单纯形态学成像相比，PET-CT 检测 LSR 的准确性较高，但尚未定义国际上公认的图像解释标准。我们的目的是评估 RFA 后 FDG-PET-CT 图像解释的标准，并确定检测 LSR 的随访时间表。
纳入 2005 年至 2011 年间接受 RFA 治疗结直肠癌肝转移且治疗后一年内进行 FDG-PET 随访的患者。重复 FDG-PET 扫描的结果进行评估，直到诊断出 LSR。结果：79 例患者共进行了 179 次 FDG-PET 扫描，57 次扫描（72%）在治疗后 6 个月内进行。30 例患者发生局部复发，其中 29 例（97%）在 1 年内发生。仅 2%的<1cm 病变和 4%的<2cm 病变出现 LSR。
大多数局部复发发生在 RFA 后 1 年内。建议在此期间使用 FDG-PET-CT 进行定期随访，以便进行重复治疗。边缘摄取可能会持续到 4-6 个月，从而使评估复杂化。<2cm 病变的随访可能受益有限。
