Treatment Outcomes and Patterns of Failure in Patients Who Underwent Postoperative Radiation Therapy for Major Salivary Gland Carcinomas

Abstract

N1 disease (91.2% vs 72.3%, P<.001), had larger LN size on physical examination (P<.001), and had more patients with T2N1 disease (P<.001) than those patients treated with IMRT alone. For the chemotherapy regimen, 57 patients were treated with concurrent weekly cisplatin 40 mg/m 2 and 59 patients were treated with 3 weekly cisplatin 100 mg/m 2 . Eight patients were treated with concurrent carboplatin. There was no difference between the use of RT dosage, mostly 70 Gy over 33 fractions. There is no statistical difference in 5-year cancer-specific survival (88.5% vs 90.8%, PZ0.89) and 5 year progression-free survival (87% vs 85.6%, PZ.75) between the CRT and IMRT alone groups. Overall local recurrence (5.6% vs 7.0%), regional recurrence (6.5% vs 1.2%), and distant metastasis rates (11.3% vs 9.3%) were not statistically different in the CRT and IMRT alone groups. A distant metastasis rate of T2N0 and T1N1 with LN2 cm is low (6.1% and 7.8%) with or without concurrent chemotherapy. For patients with T1N1 with LN >2cm, 10.5% had distant metastasis (3 of 33 patients in the CRT group and 1 of 5 in the IMRT group). For patients with T2N1 with LN <2cm, there was a low distant metastasis rate in both the CRT and IMRT groups (11.1% and 6.7%). However, for T2N1 with LN >2cm, 5 of 28 and 2 of 5 patients had distant metastasis in the CRT and IMRT alone groups, respectively. Conclusion: Concurrent chemoradiation seems to have no role in T2N0 and T1N1 NPC patients with small LN size. Concurrent chemotherapy may have a role in decreasing the distant metastasis rate in patients with T1N1 and T2N1 disease with large LN size. Further investigation is warranted.