BACKGROUND Tumor shape is strongly associated with some tumor's genomic subtypes and patient outcomes. Our purpose is to find the relationship between risk stratification and the shape of GISTs. METHODS A total of 101 patients with primary GISTs were confirmed by pathology and immunohistochemistry and underwent enhanced CT examination. All lesions' pathologic sizes were 1 to 10 cm. Points A and B were the extremities of the longest diameter (LD) of the tumor and points C and D the extremities of the small axis, which was the longest diameter perpendicular to AB. The four angles of the quadrangle ABCD were measured and each angle named by its summit (A, B, C, D). For regular lesions, we took angles A and B as big angle (BiA) and small angle (SmA). For irregular lesions, we compared A/B ratio and D/C ratio and selected the larger ratio for analysis. The chi-square test, t test, ROC analysis, and hierarchical or binary logistic regression analysis were used to analyze the data. RESULTS The BiA/SmA ratio was an independent predictor for risk level of GISTs (p = 0.019). With threshold of BiA at 90.5°, BiA/SmA ratio at 1.35 and LD at 6.15 cm, the sensitivities for high-risk GISTs were 82.4%, 85.3%, and 83.8%, respectively; the specificities were 87.1%, 71%, and 77.4%, respectively; and the AUCs were 0.852, 0.818, and 0.844, respectively. LD could not effectively distinguish between intermediate-risk and high-risk GISTs, but BiA could (p < 0.05). Shape and Ki-67 were independent predictors of the mitotic value (p = 0.036 and p < 0.001, respectively), and the accuracy was 87.8%. CONCLUSIONS Quantifying tumor shape has better predictive efficacy than LD in predicting the risk level and mitotic value of GISTs, especially for high-risk grading and mitotic value > 5/50HPF. KEY POINTS • The BiA/SmA ratio was an independent predictor affecting the risk level of GISTs. LD could not effectively distinguish between intermediate-risk and high-risk GISTs, but BiA could. • Shape and Ki-67 were independent predictors of the mitotic value. • The method for quantifying the tumor shape has better predictive efficacy than LD in predicting the risk level and mitotic value of GISTs.

中文翻译：

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GIST 的风险分层：CT 的形状量化是一个预测因素。

背景肿瘤形状与一些肿瘤的基因组亚型和患者结果密切相关。我们的目的是找出风险分层与 GIST 形状之间的关系。方法101例原发性GIST患者均经病理及免疫组化证实并行增强CT检查。所有病变的病理尺寸均为 1 至 10 厘米。点 A 和 B 是肿瘤最长直径 (LD) 的末端，点 C 和 D 是小轴的末端，这是垂直于 AB 的最长直径。测量了四边形 ABCD 的四个角，每个角都以其顶点命名（A、B、C、D）。对于规则病灶，我们将角度A和B作为大角度（BiA）和小角度（SmA）。对于不规则病变，我们比较了 A/B 比率和 D/C 比率，并选择较大的比率进行分析。使用卡方检验、t检验、ROC分析和分层或二元逻辑回归分析来分析数据。结果 BiA/SmA 比率是 GIST 风险水平的独立预测因子 (p = 0.019)。BiA 阈值为 90.5°，BiA/SmA 比值为 1.35，LD 为 6.15 cm，高危 GIST 的敏感性分别为 82.4%、85.3% 和 83.8%；特异性分别为87.1%、71%和77.4%；AUC 分别为 0.852、0.818 和 0.844。LD 无法有效区分中等风险和高风险 GIST，但 BiA 可以（p < 0.05）。形状和 Ki-67 是有丝分裂值的独立预测因子（分别为 p = 0.036 和 p < 0.001），准确率为 87.8%。结论 量化肿瘤形状在预测 GIST 的风险水平和有丝分裂值方面比 LD 具有更好的预测效果，特别是对于高风险分级和有丝分裂值 > 5/50HPF。要点 • BiA/SmA 比率是影响 GIST 风险水平的独立预测因子。LD 无法有效区分中等风险和高风险 GIST，但 BiA 可以。• 形状和Ki-67 是有丝分裂值的独立预测因子。• 量化肿瘤形状的方法在预测GI​​STs 的风险水平和有丝分裂值方面比LD 具有更好的预测效果。要点 • BiA/SmA 比率是影响 GIST 风险水平的独立预测因子。LD 无法有效区分中等风险和高风险 GIST，但 BiA 可以。• 形状和Ki-67 是有丝分裂值的独立预测因子。• 量化肿瘤形状的方法在预测GI​​STs 的风险水平和有丝分裂值方面比LD 具有更好的预测效果。要点 • BiA/SmA 比率是影响 GIST 风险水平的独立预测因子。LD 无法有效区分中等风险和高风险 GIST，但 BiA 可以。• 形状和Ki-67 是有丝分裂值的独立预测因子。• 量化肿瘤形状的方法在预测GI​​STs 的风险水平和有丝分裂值方面比LD 具有更好的预测效果。