Intratumoral Administration of Dendritic Cells Combined with Hyperthermia Induces Both Local and Systemic Antitumor Effect in Murine Tumor Models / 대한방사선종양학회지

PURPOSE: We examined whether intratumoral (i.t.) administration of dendritic cells (DCs) into a treated tumor could induce local and systemic antitumor effects in a mouse tumor model. METHODS AND MATERIALS: C57BL/6 mice were inoculated s.c. in the right and left thighs with MCA-102 fibrosarcoma cells on day 0 and on day 7, respectively. On day 7, the tumors (usually 6 mm in diameter) on the right thigh were heated by immersing the tumor-bearing leg in a circulating water bath at 43 degrees C for 30 min; thereafter, the immature DCs were i.t administered to the right thigh tumors. This immunization procedure was repeated on days 7, 14 and 21. The tumors in both the right and left thighs were measured every 7 days and the average sizes were determined by applying the following formula, tumor size=0.5 x (length+width). Cytotoxicity assay was done to determine tumor-specific cytotoxic T-lymphocyte activity. RESULTS: Hyperthermia induced apoptosis and heat shock proteins (HSPs) in tumor occurred maximally after 6 hr. For the local treated tumor, hyperthermia (HT) alone inhibited tumor growth compared with the untreated tumors (p<0.05), and furthermore, the i.t. administered DCs combined with hyperthermia (HT+DCs) additively inhibited tumor growth compared with HT alone (p<0.05). On the distant untreated tumor, HT alone significantly inhibited tumor growth (p<0.05), and also HT+DCs potently inhibited tumor growth (p<0.001); however, compared with HT alone, the difference was not statistically significant. In addition, HT+DCs induced strong cytotoxicity of the splenocytes against tumor cells compared to DCs or HT alone. CONCLUSION: HT+DCs induced apoptosis and increased the expression of HSPs, and so this induced a potent local and systemic antitumor response in tumor-bearing mice. This regimen may be beneficial for the treatment of human cancers.

Comparison between or =60 Gy Once-Daily Thoracic Irradiation for Patients with Limited-stage Smallcell Lung Cancer

PURPOSE: To review the treatment outcomes of patients with limited-stage small-cell lung cancer (LS-SCLC) receiving daily thoracic irradiation (RT) to > or = 60 Gy. Materials and M ethods: The records of patients treated with RT for LS-SCLC between 1990 and 2002 at Pusan National University Hospital were retrospectively reviewed. Fifty-six patients were identified who had received once-daily 1.8~2 Gy fractions from 40 Gy to 63 Gy. All patients received sequential chemotherapy and then RT. These patients were arbitrary divided two groups according to thoracic radiation dose, or =60 Gy. The time to death was assessed using actuarial method. RESULTS: Two- and 5-year overall survival rates for or =60 Gy group was 32% and 41% and 14% and 21%, respectively (p=1.6). Median overall survival for or =60 Gy group was 17 and 20 months, respectively. Two case of acute Grade 3 esophagitis and one case of acute Grade 4 pneumonitis developed in > or =60 Gy group. The first relapse sites of chest for or =60 Gy group were 9/15 (60%) and 3/8 (38%), respectively (p=0.4). CONCLUSION: > or =60 Gy once-daily thoracic radiotherapy was generally well tolerated and moderately improves local control compared to <60 Gy in patients with LS_ SCLC who are treated with combination chemotherapy