Application of cyberknife in treatment of retroperitoneal lymph node metastatic tumors in 81 cases / 中华放射肿瘤学杂志

ABSTRACT

Objective@#To evaluate the clinical efficacy and side effects of cyberknife therapy in the treatment of retroperitoneal lymph node metastatic tumor.@*Methods@#Among the 81 patients presenting with postoperative retroperitoneal lymph node metastases, 33 cases suffered from abdominal pain or low back pain, 7 had unilateral hydronephrosis and ureteral dilatation, and 8 developed unilateral or bilateral lower limb swelling. Using stereotactic radiotherapy with a cyberknife, DT was delivered at 33-45 Gy/3-6 F. The improvement of symptoms, objective tumor response rate, and irradiation-induced side effects were observed.@*Results@#At 4 weeks after treatment, pain and swelling of the lower extremities were completely mitigated, and hydronephrosis was fully healed in all patients. Enhanced CT or MRI was performed every 2 to 3 months. After 6-month follow-up, the complete response (CR) rate was calculated as 77%(62/81), 21%(17/81) for the partial response (PR) rate, 3%(2/81) for the stable disease (SD) rate and the effective rate (CR+ PR) was 98%.No case progressed. The main side effect was intestinal injury, including grade 1 in 16%(13/81), grade 2 in 9%(7/81). Multivariate analysis demonstrated the CR rate was not correlated with the type of the primary tumor or the size of the tumor (P>0.05), but was significantly associated with the distance of>0.5 cm between the tumor and intestine and the BED (α/β=10)>70 Gy of the tumor irradiation (P<0.01). The incidence of irradiation-related side effects was correlated with the maximum diameter of tumor>5 cm and the distance of<0.5 cm between the tumor and intestine (P<0.01).@*Conclusion@#Cyberknife is an efficacious and safe approach in the treatment of retroperitoneal lymph node metastatic tumors.