如何用 python 提取 xml 文件中医学图像分割的标注框

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1[{"points": [{"x": 385, "y": 182}, {"x": 398, "y": 179}, {"x": 404, "y": 176}, {"x": 409, "y": 173}, {"x": 415, "y": 159}, {"x": 417, "y": 153}, {"x": 421, "y": 143}, {"x": 421, "y": 136}, {"x": 419, "y": 76}, {"x": 412, "y": 73}, {"x": 406, "y": 69}, {"x": 393, "y": 61}, {"x": 390, "y": 57}, {"x": 383, "y": 53}, {"x": 378, "y": 50}, {"x": 369, "y": 44}, {"x": 360, "y": 42}, {"x": 352, "y": 42}, {"x": 348, "y": 42}, {"x": 340, "y": 41}, {"x": 331, "y": 40}, {"x": 321, "y": 40}, {"x": 311, "y": 39}, {"x": 304, "y": 39}, {"x": 294, "y": 42}, {"x": 270, "y": 43}, {"x": 264, "y": 42}, {"x": 253, "y": 41}, {"x": 242, "y": 39}, {"x": 231, "y": 37}, {"x": 221, "y": 36}, {"x": 209, "y": 35}, {"x": 190, "y": 39}, {"x": 164, "y": 49}, {"x": 158, "y": 51}, {"x": 146, "y": 69}, {"x": 137, "y": 80}, {"x": 133, "y": 89}, {"x": 136, "y": 236}, {"x": 142, "y": 244}, {"x": 149, "y": 251}, {"x": 161, "y": 261}, {"x": 210, "y": 271}, {"x": 217, "y": 274}, {"x": 223, "y": 279}, {"x": 228, "y": 284}, {"x": 235, "y": 290}, {"x": 261, "y": 294}, {"x": 301, "y": 296}, {"x": 309, "y": 294}, {"x": 320, "y": 287}, {"x": 326, "y": 283}, {"x": 327, "y": 281}, {"x": 332, "y": 271}, {"x": 338, "y": 263}, {"x": 347, "y": 253}, {"x": 348, "y": 240}, {"x": 349, "y": 222}, {"x": 360, "y": 212}, {"x": 369, "y": 207}, {"x": 372, "y": 198}, {"x": 382, "y": 183}, {"x": 383, "y": 181}, {"x": 386, "y": 181}], "annotation": {}, "regionType": "freehand"}]

xml文件中的标注信息如上，是结节区域的坐标点，目前只查到了矩形框的提取，不知道这种不规则的该怎么提取？请大神赐教。