Efficacy And Factors Affecting Outcomes Of Re-Irradiation Using Conformal Radiation Therapy In Patients With Locally-Recurrent Nasopharyngeal Carcinoma

Purpose/Objective(s)Although excellent long-term local control can be achieved by radiation therapy (RT) for nasopharyngeal carcinoma (NPC), local recurrence remains a major cause of treatment failure. Modern RT technique of three-dimensional conformal radiation therapy (3D-CRT) including intensity modulated radiation therapy (IMRT) may improve the therapeutic ratio by reducing doses to normal tissue. The aim of this study is to evaluate the efficacy and prognostic factors in patients with locally recurrent NPC who were re-irradiated using modern radiation therapy techniques.Materials/MethodsBetween January 2003 and January 2010, 709 consecutive patients diagnosed of NPC treated at our institute were retrospectively reviewed. Of these, 34 patients experienced locally recurrence and re-irradiated with conformal radiation therapy techniques were enrolled in this study. Fourteen patients received 3D-CRT, and 20 patients received IMRT. The median dose was 60 Gy (range, 44-70 Gy). There were 25 men and 9 women, with a median age of 50 years (range, 27-79 years). The median time from the first treatment to the date of recurrence was 2.94 years (range, 0.7-11.4 years). Fifty-six percent of the patients had recurrent T3-4 stage tumors. Thirty patients (88%) also received chemotherapy, 87% of which was cisplatin-based.ResultsThe median follow-up time was 25.2 months for all of the patients and 36.3 months for all of the surviving patients. The 3-year locoregional progression-free survival, progression-free survival, distant metastasis-free survival and overall survival (OS) rates were 59.0, 56.8, 74.6, and 60.2%, respectively. During the follow-up, re-failure was observed locoregionally in 9 patients (26.5%), distant metastasis was observed in 2 patients (5.9%) and both locoregional and distant failures were observed in 7 patients (20.6%). The most important prognostic factor was recurrent T stage. Patients with rT1-2 stage tumors had significantly longer 3-year OS rates than those with rT3-4 tumors (87.5 vs 31.8%, p = 0.01). A lower incidence of grade ≥3 late toxicities was observed in patients treated with IMRT than in those treated with 3D-CRT.ConclusionsRe-irradiation with modern radiation therapy techniques provides favorable outcomes in patients with locoregional recurrent NPC compared with historical series using conventional radiation therapy. Late toxicity remains a concern, but severe late toxicity appears to be less common with the use of IMRT. Purpose/Objective(s)Although excellent long-term local control can be achieved by radiation therapy (RT) for nasopharyngeal carcinoma (NPC), local recurrence remains a major cause of treatment failure. Modern RT technique of three-dimensional conformal radiation therapy (3D-CRT) including intensity modulated radiation therapy (IMRT) may improve the therapeutic ratio by reducing doses to normal tissue. The aim of this study is to evaluate the efficacy and prognostic factors in patients with locally recurrent NPC who were re-irradiated using modern radiation therapy techniques. Although excellent long-term local control can be achieved by radiation therapy (RT) for nasopharyngeal carcinoma (NPC), local recurrence remains a major cause of treatment failure. Modern RT technique of three-dimensional conformal radiation therapy (3D-CRT) including intensity modulated radiation therapy (IMRT) may improve the therapeutic ratio by reducing doses to normal tissue. The aim of this study is to evaluate the efficacy and prognostic factors in patients with locally recurrent NPC who were re-irradiated using modern radiation therapy techniques. Materials/MethodsBetween January 2003 and January 2010, 709 consecutive patients diagnosed of NPC treated at our institute were retrospectively reviewed. Of these, 34 patients experienced locally recurrence and re-irradiated with conformal radiation therapy techniques were enrolled in this study. Fourteen patients received 3D-CRT, and 20 patients received IMRT. The median dose was 60 Gy (range, 44-70 Gy). There were 25 men and 9 women, with a median age of 50 years (range, 27-79 years). The median time from the first treatment to the date of recurrence was 2.94 years (range, 0.7-11.4 years). Fifty-six percent of the patients had recurrent T3-4 stage tumors. Thirty patients (88%) also received chemotherapy, 87% of which was cisplatin-based. Between January 2003 and January 2010, 709 consecutive patients diagnosed of NPC treated at our institute were retrospectively reviewed. Of these, 34 patients experienced locally recurrence and re-irradiated with conformal radiation therapy techniques were enrolled in this study. Fourteen patients received 3D-CRT, and 20 patients received IMRT. The median dose was 60 Gy (range, 44-70 Gy). There were 25 men and 9 women, with a median age of 50 years (range, 27-79 years). The median time from the first treatment to the date of recurrence was 2.94 years (range, 0.7-11.4 years). Fifty-six percent of the patients had recurrent T3-4 stage tumors. Thirty patients (88%) also received chemotherapy, 87% of which was cisplatin-based. ResultsThe median follow-up time was 25.2 months for all of the patients and 36.3 months for all of the surviving patients. The 3-year locoregional progression-free survival, progression-free survival, distant metastasis-free survival and overall survival (OS) rates were 59.0, 56.8, 74.6, and 60.2%, respectively. During the follow-up, re-failure was observed locoregionally in 9 patients (26.5%), distant metastasis was observed in 2 patients (5.9%) and both locoregional and distant failures were observed in 7 patients (20.6%). The most important prognostic factor was recurrent T stage. Patients with rT1-2 stage tumors had significantly longer 3-year OS rates than those with rT3-4 tumors (87.5 vs 31.8%, p = 0.01). A lower incidence of grade ≥3 late toxicities was observed in patients treated with IMRT than in those treated with 3D-CRT. The median follow-up time was 25.2 months for all of the patients and 36.3 months for all of the surviving patients. The 3-year locoregional progression-free survival, progression-free survival, distant metastasis-free survival and overall survival (OS) rates were 59.0, 56.8, 74.6, and 60.2%, respectively. During the follow-up, re-failure was observed locoregionally in 9 patients (26.5%), distant metastasis was observed in 2 patients (5.9%) and both locoregional and distant failures were observed in 7 patients (20.6%). The most important prognostic factor was recurrent T stage. Patients with rT1-2 stage tumors had significantly longer 3-year OS rates than those with rT3-4 tumors (87.5 vs 31.8%, p = 0.01). A lower incidence of grade ≥3 late toxicities was observed in patients treated with IMRT than in those treated with 3D-CRT. ConclusionsRe-irradiation with modern radiation therapy techniques provides favorable outcomes in patients with locoregional recurrent NPC compared with historical series using conventional radiation therapy. Late toxicity remains a concern, but severe late toxicity appears to be less common with the use of IMRT. Re-irradiation with modern radiation therapy techniques provides favorable outcomes in patients with locoregional recurrent NPC compared with historical series using conventional radiation therapy. Late toxicity remains a concern, but severe late toxicity appears to be less common with the use of IMRT.