Ito Kei, Shimizuguchi Takuya, Nihei Keiji, Furuya Tomohisa, Ogawa Hiroaki, Tanaka Hiroshi, Sasai Keisuke, Karasawa Katsuyuki
Division of Radiation Oncology, Department of Radiology, Tokyo Metropolitan Cancer and Infectious Diseases Center, Komagome Hospital, Tokyo, Japan; Department of Radiology, Graduate School of Medicine, Juntendo University, Tokyo, Japan.
Division of Radiation Oncology, Department of Radiology, Tokyo Metropolitan Cancer and Infectious Diseases Center, Komagome Hospital, Tokyo, Japan.
Int J Radiat Oncol Biol Phys. 2018 Jan 1;100(1):159-161. doi: 10.1016/j.ijrobp.2017.08.045. Epub 2017 Sep 5.
To analyze the detailed pattern of intraosseous failure after stereotactic body radiation therapy (SBRT) for coxal bone metastasis.
Patients treated with SBRT to coxal bone metastasis were identified by retrospective chart review. The SBRT doses were 30 Gy or 35 Gy in 5 fractions. A margin of 5 to 10 mm was added to the gross tumor volume to create the clinical target volume. We evaluated the presence or absence of intraosseous recurrence using magnetic resonance imaging. Intraosseous recurrences were assessed as "in-field" or "marginal/out-of-field." In addition, we measured the distance between the center of the recurrent tumor and the nearest edge of the initial bone metastasis in cases of marginal/out-of-field recurrence.
Seventeen patients treated for 17 coxal bone metastases were included. Median age was 64 years (range, 48-79 years). Coxal lesions involved the ilium in 14 cases, pubis in 3, and ischium in 4 (3 lesions crossed over multiple regions). Patients most commonly had renal cell carcinoma (29.4%), followed by lung, hepatic cell, and colorectal cancers (23.5%, 11.8%, and 11.8%, respectively). Median follow-up after SBRT was 13 months (range, 2-44 months). Among all 17 cases, 7 cases developed 8 intraosseous recurrences, including in-field recurrence in 1 case and marginal/out-of-field recurrences in 7 cases. Median time to intraosseous recurrence was 10 months (range, 2-35 months). Among 7 cases with marginal/out-of-field recurrence, mean distance to the center of the recurrent tumor from the nearest edge of the initial bone metastasis was 34 mm (range, 15-55 mm).
Most recurrences were observed out-of-field in the same coxal bone. These results suggest that defining the optimal clinical target volume in SBRT for coxal bone metastasis to obtain sufficient local tumor control is difficult.
分析立体定向体部放射治疗（SBRT）用于髋骨转移瘤后骨内失败的详细模式。
通过回顾性病历审查确定接受SBRT治疗髋骨转移瘤的患者。SBRT剂量为30 Gy或35 Gy，分5次给予。在大体肿瘤体积周围增加5至10 mm的边界以形成临床靶体积。我们使用磁共振成像评估骨内复发的有无。骨内复发被评估为“野内”或“边缘/野外”。此外，在边缘/野外复发的病例中，我们测量了复发肿瘤中心与初始骨转移瘤最近边缘之间的距离。
纳入了17例接受1次SBRT治疗髋骨转移瘤的患者。中位年龄为64岁（范围48 - 79岁）。髋部病变累及髂骨14例，耻骨3例，坐骨4例（3处病变跨越多个区域）。患者最常见的是肾细胞癌（29.4%），其次是肺癌、肝细胞癌和结直肠癌（分别为23.5%、11.8%和11.8%）。SBRT后的中位随访时间为13个月（范围2 - 44个月）。在所有17例病例中，7例出现8处骨内复发，包括野内复发1例和边缘/野外复发7例。骨内复发的中位时间为10个月（范围2 - 35个月）。在7例边缘/野外复发的病例中，复发肿瘤中心距初始骨转移瘤最近边缘的平均距离为34 mm（范围15 - 55 mm）。
大多数复发发生在同一髋骨的野外。这些结果表明，在SBRT中确定髋骨转移瘤的最佳临床靶体积以获得足够的局部肿瘤控制是困难的。
