Radiation Therapy Combined with (or without) Cisplatin-based Chemotherapy for Patients with Nasopharyngeal Cancer: 15-years Experience of a Single Institution in Korea / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: This retrospective study was carried out to evaluate the efficacy and toxicity of radiation therapy (RT) with/without cisplatin-based chemotherapy in nasopharyngeal cancer (NPC). MATERIALS AND METHODS: One hundred forty six patients with NPC received curative RT and/or cisplatin-based chemotherapy. Thirty-nine patients were treated with induction chemotherapy (IC), including cisplatin and 5-fluorouracil followed by RT. Another 63 patients were treated with concurrent chemoradiotherapy (CCRT) using cisplatin, and 22 patients were treated with IC followed by CCRT. The remaining 22 patients were treated with RT alone. RESULTS: One hundred four (80.0%) patients achieved complete response (CR), and 23 (17.7%) patients achieved partial response (PR). The patterns of failure were: locoregional recurrences in 21.2% and distant metastases in 17.1%. Five-year overall survival (OS) and progression free survival (PFS) were 50.7% and 45.0%, respectively. Multivariate Cox stepwise regression analysis revealed CR to chemoradiotherapy to be a powerful prognostic factor for OS. CR to chemoradiotherapy and completion of radiation according to the time schedule were favorable prognostic factors for PFS. A comparison of each treatment group (IC --> RT vs. CCRT vs. IC --> CCRT vs. RT alone) revealed no significant differences in the OS or PFS. However, subgroup analysis showed significant differences in both OS and DFS in favor of the combined chemoradiotherapy group compared with RT alone, for stage IV and T3-4 tumors. Grade 3-4 toxicities were more common in the combined chemoradiotherapy arm, particularly in the CCRT group. CONCLUSIONS: This study was limited in that it was a retrospective study, much time was required to collect patients, and there were imbalances in the number of patients in each treatment group. Combined chemoradiotherapy remarkably prolonged the OS and PFS in subgroup patients with stage IV or T3-4 NPC.

Radiation Response Modulation of GW572016 (EGFR/HER2 Dual Tyrosine Kinase Inhibitor) in Human Breast Cancer Xenografts / 대한방사선종양학회지

PURPOSE: We examined the effect of the dual EGFR/HER2 tyrosine kinase inhibitor, GW572016, on EGFR/HER2 receptor phosphorylation, inhibition of downstream signaling and radiosensitization in either an EGFR or HER2 overexpressing human breast cancer xenograft. MATERIALS AND METHODS: We established SCID mice xenografts from 4 human breast cancer cell line that overexpressed EGFR or HER 2 (SUM 102, SUM 149, SUM 185, SUM 225). Two series of xenografts were established. One series was established for determining inhibition of the EGFR/HER2 receptor and downstream signaling activities by GW572016. The other series was established for determining the radiosensitization effect of GW572016. Inhibition of the receptor and downstream signaling proteins were measured by the use of immunoprecipitation and Western blotting. For determining the in vivo radiosensitization effect of GW572016, we compared tumor growth delay curves in the following four treatment arms: a) control; b) GW572016 alone; c) radiotherapy (RT) alone; d) GW572016 and RT. RESULTS: GW572016 inhibited EGFR, HER2 receptor phosphorylation in SUM 149 and SUM 185 xenografts. In addition, the p44/42 MAPK (ERK 1/2) downstream signaling pathway was inactivated by GW572016 in the SUM 185 xenograft. In the SUM 225 xenograft, we could not observe inhibition of HER2 receptor phosphorylation by GW572016; both p44/42 MAPK (Erk1/2) and Akt downstream signal protein phosphorylation were inhibited by GW572016. GW572016 inhibited growth of the tumor xenograft of SUM 149 and SUM 185. The combination of GW572016 and RT enhanced growth inhibition greater than that with GW572016 alone or with RT alone in the SUM 149 xenograft. GW572016 appears to act as an in vivo radiosensitizer. CONCLUSION: GW572016 inhibited EGFR/HER2 receptor phosphorylation and downstream signaling pathway proteins. GW572016 modestly inhibited the growth of tumor in the SUM 185 xenograft and showed radiosensitization in the SUM 149 xenograft. Our results suggest that a better predictor of radiation response would be inhibition of a crucial signaling pathway than inhibition of a receptor.

Early Therapeutic Effects of Cyberknife Radiosurgery on Trigeminal Neuralgia / 대한방사선종양학회지

PURPOSE: We evaluated whether Cyberknife radiosurgery is an effective and safe method of therapy for medically intractable trigeminal neuralgia (TN). MATERIALS AND METHODS: We retrospectively analyzed the outcome of 26 patients, who failed to surgery or were not suitable candidates for invasive intervention and were treated by Cyberknife radiosurgery between March 2004 and May 2005. Radiosurgery doses of 60~64 Gy were delivered to the 80% isodose line prescribed to an 6 mm length of the nerve, sparing the most proximal 3 mm away from the trigeminal nerve root entry zone (median dose: 64 Gy). RESULTS: Follow-up period was 3~15 months (median follow-up period: 9 months) Preliminary results from a cohort of 26 patients undergoing Cyberknife radiosurgery for TN showed that pain relief was achieved in 50% (13/26) of patients within the first 24 hrs after treatment. At last follow-up, 96.2% (25/26) of patients reported early pain relief within 7 days. Treatment failure developed in 2 of 26. Poor response occurred in one patient and relapse was observed in the other patient. 3 patients had hypoesthesia (11.5%), which was the only complication observed with any of our patients. CONCLUSION: With these results, authors assumed that Cyberknife radiosurgery for TN could be one of safe and effective therapeutic methods.