Putta Tharani, Gibikote Sridhar, Madhuri Vrisha, Walter Noel
Department of Radiology, Christian Medical College, Vellore, Tamil Nadu, India.
Department of Paediatric Orthopaedics, Christian Medical College, Vellore, Tamil Nadu, India.
Pol J Radiol. 2016 Nov 16;81:540-548. doi: 10.12659/PJR.898108. eCollection 2016.
It is imperative that bone tumour margin and extent of tumour involvement are accurately assessed pre-operatively in order for the surgeon to attain a safe surgical margin. In this study, we comprehensively assessed each of the findings that influence surgical planning, on various MRI sequences and compared them with the gold standard - pathology.
MATERIAL/METHODS: In this prospective study including 21 patients with extremity bone tumours, margins as seen on various MRI sequences (T1, T2, STIR, DWI, post-gadolinium T1 FS) were measured and biopsies were obtained from each of these sites during the surgical resection. The resected tumour specimen and individual biopsy samples were studied to assess the true tumour margin. Margins on each of the MRI sequences were then compared with the gold standard - pathology. In addition to the intramedullary tumour margin, we also assessed the extent of soft tissue component, neurovascular bundle involvement, epiphyseal and joint involvement, and the presence or absence of skip lesions.
T1-weighted imaging was the best sequence to measure tumour margin without resulting in clinically significant underestimation or overestimation of the tumour extent (mean difference of 0.8 mm; 95% confidence interval between -0.9 mm to 2.5 mm; inter-class correlation coefficient of 0.998). STIR and T1 FS post-gadolinium imaging grossly overestimated tumour extent by an average of 16.7 mm and 16.8 mm, respectively (P values <0.05). Post-gadolinium imaging was better to assess joint involvement while T1 and STIR were the best to assess epiphyseal involvement.
T1-weighted imaging was the best sequence to assess longitudinal intramedullary tumour extent. We suggest that osteotomy plane 1.5 cm beyond the T1 tumour margin is safe and also limits unwarranted surgical bone loss. However, this needs to be prospectively proven with a larger sample size.
为使外科医生获得安全的手术切缘，术前准确评估骨肿瘤的边界和肿瘤累及范围至关重要。在本研究中，我们全面评估了各种MRI序列上影响手术规划的各项发现，并将其与金标准——病理结果进行比较。
材料/方法：在这项前瞻性研究中，纳入了21例四肢骨肿瘤患者，测量了各种MRI序列（T1、T2、短TI反转恢复序列（STIR）、扩散加权成像（DWI）、钆增强T1脂肪抑制序列（T1 FS））上所见的边界，并在手术切除过程中从每个部位获取活检样本。对切除的肿瘤标本和各个活检样本进行研究，以评估真正的肿瘤边界。然后将每个MRI序列上的边界与金标准——病理结果进行比较。除了评估髓内肿瘤边界外，我们还评估了软组织成分的范围、神经血管束受累情况、骨骺和关节受累情况以及跳跃性病变的有无。
T1加权成像在测量肿瘤边界方面是最佳序列，不会导致对肿瘤范围的临床显著低估或高估（平均差异为0.8mm；95%置信区间为-0.9mm至2.5mm；组内相关系数为0.998）。钆增强后的STIR和T1 FS成像分别平均高估肿瘤范围16.7mm和16.8mm（P值<0.05）。钆增强成像在评估关节受累方面更佳，而T1和STIR在评估骨骺受累方面最佳。
T1加权成像在评估纵向髓内肿瘤范围方面是最佳序列。我们建议在T1肿瘤边界以外1.5cm处进行截骨是安全的，并且还能限制不必要的手术骨质丢失。然而，这需要通过更大样本量的前瞻性研究来证实。
