Schwartz David L, Lobo Mark J, Ang K Kian, Morrison William H, Rosenthal David I, Ahamad Anesa, Evans Douglas B, Clayman Gary, Sherman Steven I, Garden Adam S
Department of Radiation Oncology, UT MD Anderson Cancer Center, Houston, TX 77030, USA.
Int J Radiat Oncol Biol Phys. 2009 Jul 15;74(4):1083-91. doi: 10.1016/j.ijrobp.2008.09.023. Epub 2008 Dec 25.
To review institutional outcomes for patients treated for differentiated thyroid cancer with postoperative conformal external beam radiotherapy (EBRT).
This is a single-institution retrospective review of 131 consecutive patients with differentiated thyroid cancer who underwent EBRT between January 1996 and December 2005. Histologic diagnoses included 104 papillary, 21 follicular, and six mixed papillary-follicular types. American Joint Committee on Cancer stage distribution was Stage III in 2 patients, Stage IVa-IVc in 128, and not assessable in 1. Thirty-four patients (26%) had high-risk histologic types and 76 (58%) had recurrent disease. Extraglandular disease spread was seen in 126 patients (96%), microscopically positive surgical margins were seen in 62 patients (47%), and gross residual disease was seen in 15 patients (11%). Median EBRT dose was 60 Gy (range, 38-72 Gy). Fifty-seven patients (44%) were treated with intensity-modulated radiotherapy (IMRT) to a median dose of 60 Gy (range, 56-66 Gy). Median follow-up was 38 months (range, 0-134 months).
Kaplan-Meier estimates of locoregional relapse-free survival, disease-specific survival, and overall survival at 4 years were 79%, 76%, and 73%, respectively. On multivariate analysis, high-risk histologic features and gross residual disease predicted for inferior locoregional relapse-free survival, whereas high-risk histologic features, M1 disease, and gross residual disease predicted for inferior disease-specific and overall survival. The IMRT did not impact on survival outcomes, but was associated with less frequent severe late morbidity (12% vs. 2%).
Postoperative conformal EBRT provides durable locoregional disease control for patients with high-risk differentiated thyroid cancer if disease is reduced to microscopic burden. Patients with gross disease face significantly worse outcomes. The IMRT may significantly reduce chronic radiation morbidity, but requires additional study.
回顾采用术后适形外照射放疗（EBRT）治疗分化型甲状腺癌患者的机构治疗结果。
这是一项单机构回顾性研究，纳入了1996年1月至2005年12月期间连续接受EBRT治疗的131例分化型甲状腺癌患者。组织学诊断包括104例乳头状癌、21例滤泡状癌和6例乳头状-滤泡状混合型癌。美国癌症联合委员会（AJCC）分期分布为：2例为III期，128例为IVa-IVc期，1例不可评估。34例（26%）患者具有高危组织学类型，76例（58%）患者有复发性疾病。126例（96%）患者出现腺外疾病扩散，62例（47%）患者手术切缘镜下阳性，15例（11%）患者有大体残留疾病。EBRT中位剂量为60 Gy（范围38 - 72 Gy）。57例（44%）患者接受调强放疗（IMRT），中位剂量为60 Gy（范围56 - 66 Gy）。中位随访时间为38个月（范围0 - 134个月）。
4年时局部区域无复发生存率、疾病特异性生存率和总生存率的Kaplan-Meier估计值分别为79%、76%和73%。多因素分析显示，高危组织学特征和大体残留疾病预示局部区域无复发生存率较差，而高危组织学特征、M1期疾病和大体残留疾病预示疾病特异性生存率和总生存率较差。IMRT对生存结果无影响，但与严重晚期并发症发生率较低相关（12%对2%）。
如果疾病降至镜下负担水平，术后适形EBRT可为高危分化型甲状腺癌患者提供持久的局部区域疾病控制。有大体疾病的患者预后明显较差。IMRT可能显著降低慢性放射并发症，但需要进一步研究。
