Mahnken Andreas H, Bruners Philipp, Delbrück Heide, Günther Rolf W, Plumhans Cedric
Department of Diagnostic and Interventional Radiology, RWTH Aachen, Aachen, Germany.
J Med Imaging Radiat Oncol. 2012 Dec;56(6):617-21. doi: 10.1111/j.1754-9485.2012.02443.x. Epub 2012 Sep 5.
Osteoid osteoma is a painful benign tumour, which is commonly treated by radiofrequency ablation (RFA). The goal of this study is to assess the value of contrast-enhanced magnetic resonance imaging (MRI) for predicting clinical success after RFA of osteoid osteoma.
Twenty consecutive patients (14 male, 6 female; mean age 23.3 ± 13.4 years) suffering from osteoid osteoma underwent unenhanced and contrast-enhanced T1-weighted MRI the day after RFA. Post-interventional contrast enhancement of the nidus was analyzed by comparing signal-to-noise ratios (SNR) of the nidus before and after contrast administration. The SNR between pre- and post-contrast scans was computed.
There were no significant differences in SNR between pre- and post-contrast scans in the area of ablation (P = 0.1583), while the SNR exceeded one in four patients, indicating residual contrast enhancement. In three of these patients clinical symptoms recurred, requiring re-ablation, while one patient remained free from symptoms during follow-up. In patients with a pre- and post-contrast SNR of ≤ 1.18 no local recurrence was observed.
Contrast enhancement on T1-weighted MRI imaging seems to be predictive of clinically unsuccessful RFA in osteoid osteoma. Patients with a SNR increase of ≥ 20% after contrast administration might be considered for re-ablation to avoid symptomatic tumour recurrence.
骨样骨瘤是一种引起疼痛的良性肿瘤，通常采用射频消融（RFA）治疗。本研究的目的是评估对比增强磁共振成像（MRI）在预测骨样骨瘤RFA术后临床疗效方面的价值。
连续20例骨样骨瘤患者（男14例，女6例；平均年龄23.3±13.4岁）在RFA术后第1天接受了非增强和对比增强T1加权MRI检查。通过比较对比剂注射前后瘤巢的信噪比（SNR），分析介入后瘤巢的对比增强情况。计算对比剂注射前后扫描的SNR。
消融区域对比剂注射前后的SNR无显著差异（P = 0.1583），但4例患者的SNR超过1，提示存在残余对比增强。其中3例患者临床症状复发，需要再次消融，而1例患者在随访期间无症状。对比剂注射前后SNR≤1.18的患者未观察到局部复发。
T1加权MRI成像上的对比增强似乎可预测骨样骨瘤RFA临床疗效不佳。对比剂注射后SNR增加≥20%的患者可考虑再次消融，以避免有症状的肿瘤复发。
