1. Introduction
Nasopharyngeal carcinoma (NPC) was one of the most common head and neck malignancies and was prevalent in southern China. The International Cancer Research Center reported that in 2012 the worldwide incidence of NPC was 12/100,000, whereas new cases of NPC in China accounted for 53.5% of the worldwide incidence12.
EBRT was first-line treatment modality for NPC. Approximately 20-40% of patients suffered from recurrence after EBRT3-5. With the popularity of precise EBRT and comprehensive treatment (EBRT combined with chemotherapy), the efficacy of treatment has improved greatly with a 5-year recurrence-free survival rate of 83.0-91.8%6-8. However, advanced NPC carried a poor prognosis if recurrence occurred. Thus, exploring a high efficient treatment for recurrent NPC was necessary.
Over the past few decades, improvement of surgical skills, re-irradiation, chemotherapy and other treatments have contributed to salvage treatment for recurrent NPC. For patients with early-stage recurrence, surgery could be an alternative, which would resect radiation-resistant tumors and avoid reirradiation damage as much as possible. It has been reported that 5-year LC and OS after tumor resection were 43-74% and 47-62% respectively9-13. However, most patients recurred with late-stage disease which usually unresectable14-17.
Reirradiation was one of the most common salvage treatments for recurrent NPC18. Previous studies showed that the recurrent NPC patients treated with re-irradiation, LC and OS at 3 years could reach 70-89% and 46-58%, respectively19-22. However, about 30-70% of patients were likely to develop severe (grade 3-5) complications 202123-25. Moreover, some patients might die of fatal complications, such as necrosis of the temporal lobe necrosis or carotid blowout26.
125I RSI-BT, as a local treatment, was characterized by high local dose, sharp fall-off of dose curve and little unexpected radiation effects on adjacent normal tissues. 125I RSI-BT has been considered as salvage treatment for some types of recurrent cancer, such as rectal cancer27. The advantages of CT-guidance punctures were: (1) high resolution of CT scans; (2) high precision for needles into puncture position; (3) minimal invasion and fast recovery. However, few studies of125I RSI-BT against recurrent NPC have reported. In this study we investigated the efficacy and prognosis of125I RSI-BT treatment of recurrent NPC with a long-term follow-up.