Familial Nasopharyngeal Carcinoma 6

Management of Patients with Failure Following Definitive Radiation Therapy 245Fig. 19.5. Stereotactic radiosurgery for recurrent NPC. Right:pretreatment CT scan showing recurrent tumor in the leftside of the nasopharynx extended to parapharyngeal space.Middle: target covered with single isocenter with a dose of12.5 Gy delivered to 80% isodose line. Left: CT scan at 6 monthsafter treatment showing complete resolution of tumorTable 19.2. Results in literature on stereotactic radiosurgery for local failures of NPCStudy No. of patients rT stage Dose (Gy) Tumor control rate (%) Any severe sequelae aMiller et al. (1997) 3 rT3–4 12–20 50 (1/2) NoBuatti et al. (1995) 3 rT2–4 12.5 50 (1/2) Yes (50%, 1/2)Kocher et al. (1998) 5 rT3–4 15–24 67 (2/3) Yes (60%, 3/5)Cmelak et al. (1997) 9 (12 lesions) rT3 15–20 58 (7/12) Yes (11%, 1/9)Chua et al. (2006) 48 rT1–4 8–18 54 (26/48) Yes (19%, 9/48)aSevere sequelae includes brain necrosis, cranial neuropathy and massive hemorrhagerecurrent tumor. Table 19.2 summarizes the reportedoutcome using stereotactic radiosurgery for local failureof NPC. Using stereotactic radiosurgery alone todeliver a dose of 12–24 Gy to tumor periphery yieldeda crude local control rate of 50%–67% for locallyrecurrent NPC (Buatti et al. 1995; Cmelak et al.1997; Miller et al. 1997; Kocher et al. 1998; Chuaet al. 2006). Although a wide range of dose was used inthese early studies, our experience showed that tumorcontrol rate was relatively good with a modest dose of12.5 Gy for persistent disease and tumor confined tonasopharynx (Chua et al. 2003, 2006). External beamradiotherapy and stereotactic radiosurgery have alsobeen combined to retreat NPC, usually in the managementof advanced recurrence. When stereotacticradiosurgery was administered as a boost dose afterreirradiation, the 3-year control rate ranged from 52%to 58%. Chen et al. (2001) reported the outcome of11 patients with rT3–4 NPC after conformal radiotherapyand stereotactic radiosurgery. The radiosurgerydose ranged from 10 to 19 Gy with a median of14 Gy. Significant regression of tumor was noted infive patients and limited regression in another three.Chang et al. (2000) reported 15 patients with locallyrecurrent NPC who received external reirradiationfollowed by radiosurgery using a dose ranged from 8to 15 Gy, and noted a 3-year survival rate of 52%. Paiet al. (2000) reported 36 patients with recurrent NPC,also treated with external reirradiation followed byradiosurgery boost. The radiosurgery dose to targetperiphery ranged from 8 to 20 Gy with a median of12 Gy. A 3-year local control rate of 58% was achieved.19.4.3Stereotactic RadiotherapyThe same technique may also be used to deliver multiplefractions of radiation and is termed stereotacticradiotherapy, and the control rates appeared to be similarto radiosurgery in the treatment of persistent disease(Table 19.3). For recurrent disease, stereotactic