Teh Bin S, Bloch Charles, Paulino Arnold C, Shen Steven, Hinckley Lisa, Baskin David, Butler Edward B, Amato Robert
Department of Radiology, Section of Radiation Oncology, Baylor College of Medicine, Houston, TX, USA.
Clin Genitourin Cancer. 2007 Jun;5(5):334-7. doi: 10.3816/CGC.2007.n.013.
Renal cell carcinoma (RCC) is often regarded as a radiation-resistant tumor. However, radiation therapy (RT) in the form of stereotactic radiosurgery (SRS) or whole-brain irradiation has been used to treat brain metastases from RCC. To date, there have been no clinical pathologic correlative findings before and after RT. Herein, we present a case of a patient with brain metastases from RCC treated with SRS. The diagnosis of clear-cell RCC was made in 2001 after right radical nephrectomy. He was also found to have lung metastases at diagnosis. He presented with neurologic symptoms in 2004, and magnetic resonance imaging showed 3 brain lesions with a significant amount of edema consistent with brain metastases. The largest lesion caused a midline shift and was surgically resected. Pathology revealed metastatic RCC. The other 2 smaller brain lesions were treated at 20 Gy respectively with shaped-beam SRS using the BrainLab Novalis system. No whole-brain irradiation was delivered. However, the patient had difficulty weaning off his steroids, and a magnetic resonance imaging performed 6 months after SRS was read as "progression of the lesions." He then underwent resection of both the irradiated brain lesions. Pathologic examination revealed necrotic tissues without any viable tumor identified. The patient has since been doing very well, now 18 months after SRS and 5 years from the initial diagnosis. This is the first reported case that demonstrates that precise high-dose radiation in the form of SRS can cause significant tumor cell death (pathologic complete response) in radiation-resistant brain metastases from RCC. This finding also provides a rationale to deliver stereotactic body RT for primary and metastatic RCC extracranially. A prospective clinical trial using stereotactic body RT for primary and metastatic RCC is under way.
肾细胞癌（RCC）通常被视为一种抗辐射肿瘤。然而，立体定向放射外科（SRS）或全脑照射形式的放射治疗（RT）已被用于治疗RCC的脑转移瘤。迄今为止，尚无RT前后的临床病理相关发现。在此，我们报告一例接受SRS治疗的RCC脑转移患者。2001年，患者在右肾根治性切除术后被诊断为透明细胞RCC。诊断时还发现他有肺转移。2004年，他出现神经症状，磁共振成像显示3个脑病变，伴有大量水肿，符合脑转移瘤表现。最大的病变导致中线移位，遂行手术切除。病理显示为转移性RCC。另外2个较小的脑病变分别采用BrainLab Novalis系统的塑形束SRS给予20 Gy照射。未进行全脑照射。然而，患者停用类固醇药物困难，SRS治疗6个月后进行的磁共振成像显示“病变进展”。随后，他接受了对两个照射过的脑病变的切除。病理检查显示为坏死组织，未发现任何存活肿瘤。自SRS治疗后18个月，距初始诊断已5年，患者此后情况一直良好。这是首例报告病例，表明SRS形式的精确高剂量放疗可使RCC的抗辐射脑转移瘤发生显著肿瘤细胞死亡（病理完全缓解）。这一发现也为在颅外对原发性和转移性RCC进行立体定向体部放疗提供了理论依据。一项使用立体定向体部放疗治疗原发性和转移性RCC的前瞻性临床试验正在进行中。
