SMART (Simultaneous Modulated Accelerated RadioTherapy) for locally advanced nasopharyngeal carcinomas

Abstract

Concurrent chemoradiotherapy is commonly used for locally advanced nasopharyngeal carcinoma (NPC). We retrospectively analyzed the clinical outcomes of simultaneous modulated accelerated radiotherapy (SMART) with concurrent chemotherapy. Between January 2003 and May 2005, 24 patients with stage IIB to IVB NPC underwent SMART encompassing 3 targets: gross tumor volume (GTV), high-risk subclinical disease (CTV1), and low-risk subclinical disease (CTV2). Daily fractions of 2.4, 2.15, and 1.9 Gy were delivered to GTV, CTV1, and CTV2 to a total dose of 64.8, 58.05, and 51.3 Gy in 27 fractions over 5.5 weeks, respectively. Fifteen patients received concurrent cisplatin (DDP group), and 9 received 5-fluorouracil plus cisplatin (FP group). With a median follow-up of 26 months (range, 17-45 months), 3-year overall and local-, regional-, and distant-progression-free survivals were 96% and 93%, 87%, and 88%, respectively. Grade 3 acute mucositis and pharyngitis were observed in 16 (67%) and 14 (59%) patients, respectively. Severe acute mucositis (100% vs 47%) and pharyngitis (100% vs 34%) were more frequently observed in the FP group than the DDP group (p < .01). Despite short follow-up with a small number of patients, our preliminary results demonstrated encouraging local-regional control and survival at the cost of modest increase in treatment related toxicities. The total dose and fractionation scheme of SMART used in our study is feasible with no life-threatening or fatal complications. However, the administration of fluorouracil in addition to cisplatin during SMART was associated with increased acute and late toxicities, and it should be administered with caution.