Department of Radiation Oncology, All India Institute of Medical Sciences, Rishikesh, India.
Department of Radiation Oncology, All India Institute of Medical Sciences, Rishikesh, India.
Eur J Obstet Gynecol Reprod Biol. 2022 Nov;278:189-194. doi: 10.1016/j.ejogrb.2022.09.032. Epub 2022 Sep 29.
Intensity-modulated radiotherapy (IMRT) has been used to reduce dose to bone marrow (BM) irradiation during pelvic conformal radiotherapy by contouring bone marrow and sparing it during radiotherapy planning. The present study was done to compare CT & MRI for contouring bone marrow to spare functional bone marrow for Intensity-modulated radiotherapy (IMRT) in carcinoma cervix and to assess its effect on functional outcome.
MATERIAL & METHODS: This prospective, observational study included newly diagnosed carcinoma cervix patients treated by radical chemoradiation. Patients were distributed in two arms i.e. CT arm and MRI for contouring bone marrow. Regions taken into consideration for bone marrow volumes contouring were 4th and 5th Lumbar vertebrae, whole pelvis and proximal femur upto lesser trochanter. In CT arm bone marrow regions were contoured using freehand method with window adjusted to bone range (Window - 2500/ Level - 400) and in MRI arm BM regions on the MR images that had pixel values similar to muscle or IDEAL IQ sequence based on fat fractions present in bone marrow (BM) was used to contour.
17 patients in CT arm and 19 patients in MRI arm were included. There was no significant difference between the groups in terms of Bone Marrow Volume (cm) (W = 171.500, p = 0.763). The mean value of V10, V20, V30 and V40 all were lower in group II (MRI) but the differences in volume were not significant. Bone marrow V30 in CT arm was found to correlate with absolute neutrophil count drop which was statistically significant in univariate (Coefficient - 1.00 [0.14-2.01, p = 0.025] and multivariate analysis (Coefficient - [1.08 (0.14 to 2.01, p = 0.025]). Bone marrow V30 in MRI arm was found to correlate with total leucocyte count percentage drop, which on multivariate analysis was statistically significant (Coefficient - 1.29 [0.29-2.28, p = 0.013]).
Dosimetric parameters of bone marrow V10 and V30 were found to be associated with absolute neutrophil and total leucocyte nadir respectively. Haematological toxicity was observed more in MRI arm but more propspective studies are required for further validation.
调强放疗（IMRT）通过勾画骨髓并在放疗计划中对其进行保护，从而减少盆腔适形放疗中骨髓的照射剂量。本研究旨在比较 CT 和 MRI 对宫颈癌调强放疗中骨髓的勾画，以保护功能性骨髓，并评估其对功能结果的影响。
这项前瞻性观察性研究纳入了接受根治性放化疗的新诊断宫颈癌患者。患者被分为两组，即 CT 组和 MRI 组，用于勾画骨髓。考虑到骨髓体积勾画的区域为第 4 和第 5 腰椎、整个骨盆和股骨近端至小转子。在 CT 组中，使用徒手方法对骨髓区域进行勾画，调整窗口以适应骨骼范围（窗宽 2500/窗位 400）；在 MRI 组中，使用基于骨髓中脂肪分数的 MRI 图像上与肌肉或 IDEAL IQ 序列像素值相似的方法来勾画 BM 区域。
CT 组 17 例，MRI 组 19 例。两组间骨髓体积（cm）无显著差异（W=171.500，p=0.763）。V10、V20、V30 和 V40 的平均值在第 II 组（MRI 组）中较低，但体积差异无统计学意义。CT 组中骨髓 V30 与中性粒细胞绝对计数下降相关，单因素分析（系数-1.00[0.14-2.01，p=0.025]和多因素分析（系数-1.08[0.14-2.01，p=0.025]）均有统计学意义。MRI 组中骨髓 V30 与白细胞总数百分比下降相关，多因素分析有统计学意义（系数-1.29[0.29-2.28，p=0.013]）。
骨髓 V10 和 V30 的剂量学参数与中性粒细胞绝对计数和白细胞总数最低点分别相关。MRI 组观察到更多的血液学毒性，但需要进一步的前瞻性研究来验证。
