10-Year Results of Therapeutic Ratio by Intensity-Modulated Radiotherapy Versus Two-Dimensional Radiotherapy in Patients with Nasopharyngeal Carcinoma.

BACKGROUND: The purpose of this study was to verify 10-year results of survival and late toxicities and assess the ultimate therapeutic ratio of intensity-modulated radiotherapy (IMRT) versus two-dimensional radiotherapy (2DRT) in patients with nasopharyngeal carcinoma (NPC). MATERIALS AND METHODS: We retrospectively reviewed the data from 1,276 patients with nonmetastatic NPC who received IMRT or 2DRT from January 2003 to December 2006. RESULTS: Of the 1,276 patients, 512 were treated with IMRT and 764 with 2DRT. Median follow-up was 115 months. At 10 years, the IMRT group demonstrated significantly better results than the 2DRT group in local failure-free survival (L-FFS; 90% vs. 84%; hazard ratio [HR], 0.57, 95% confidence interval [CI], 0.40-0.81; p = .001), failure-free survival (FFS; 69% vs. 58%; HR, 0.69, 95% CI, 0.57-0.83; p < .001), and overall survival (OS; 75% vs. 63%; HR, 0.62, 95% CI, 0.51-0.77; p < .001). Subgroup multivariate analyses showed that radiotherapeutic technique (IMRT vs. 2DRT) remained an independent prognostic factor for L-FFS in the T1 subgroup (HR, 0.30; 95% CI, 0.11-0.80; p = .02); for FFS in the stage II subgroup (HR, 0.42; 95% CI, 0.24-0.73; p = .002); and for OS in the stage I (HR, 0.20; 95% CI, 0.04-0.96; p = .04), stage II (HR, 0.39; 95% CI, 0.21-0.75; p = .004), and stage IVA-B (HR, 0.74, 95% CI, 0.56-0.98; p = .04) subgroups. The incidence of grade 3-4 temporal lobe necrosis, cranial neuropathy, eye damage, ear damage, neck soft tissue damage, trismus, and dry mouth was significantly lower in the IMRT group than in the 2DRT group. CONCLUSION: IMRT demonstrated an improved ultimate therapeutic ratio compared with 2DRT in patients with NPC after a 10-year follow-up, with significant improvement of L-FFS, FFS, and OS and decrease in most late toxicities. IMPLICATIONS FOR PRACTICE: The ultimate therapeutic ratio of intensity-modulated radiotherapy versus two-dimensional radiotherapy in patients with nasopharyngeal carcinoma is unclear. In this retrospective study of 1,276 patients with nonmetastatic nasopharyngeal carcinoma with a follow-up of 115 months, intensity-modulated radiotherapy demonstrated an improved ultimate therapeutic ratio compared with two-dimensional radiotherapy, with significant improvement of local failure-free survival, failure-free survival, and overall survival and decrease in most late toxicities and noncancer deaths. However, distant control remains insufficient with this treatment modality.

Brucine-loaded liposomes composed of HSPC and DPPC at different ratios: in vitro and in vivo evaluation.

OBJECTIVE: The objective of this study is to test the hypothesis that the phase transition temperature (T(m)), the main property of liposomes, can be easily controlled by changing the molar ratio of hydrogenated soy phosphatidylcholine (HSPC) and 1,2-dipalmitoyl-sn-glycero-3-phosphacholine (DPPC) after drug encapsulation. MATERIALS AND METHODS: Brucine, an antitumor alkaloid, was encapsulated into the liposomes with different HSPC/DPPC compositions. The T(m)s of the brucine-loaded liposomes (BLs) were determined by differential scanning calorimetry (DSC). Then the physicochemical properties and pharmacokinetics of the BLs with different HSPC/DPPC compositions were investigated and compared. RESULTS: The results of DSC revealed that HSPC and DPPC can combine into one phase. The findings of molecular modeling study suggested that HSPC interacts with DPPC via electrostatic interaction. The molar ratio of HSPC/DPPC influenced the sizes of BLs but had little effect on the entrapment efficiency (EE). The stability of BLs was improved with the increase of the HSPC ratios, especially with the presence of plasma. Following i.v. administration, it was found that AUC values of BLs in vivo were directly related to the HSPC/DPPC ratios of BLs, namely the T(m)s of BLs. DISCUSSION: The behavior of liposomes, especially in vivo pharmacokinetic behavior, can be controlled by the modification of T(m). CONCLUSION: The characterization of BLs in vitro and in vivo had demonstrated that the Tm could be flexibly modified for liposomes composed of both HSPC and DPPC. Using HSPC/DPPC composition may be an efficient strategy to control the T(m), thus control the in vivo pharmacokinetic behavior, of BLs.

Thermosensitive liposomes with higher phase transition temperature for targeted drug delivery to tumor.

Thermosensitive liposomes (TSL) in combination with local hyperthermia (HT) represent a promising tool for tumor specific drug delivery. The objective of the study was to investigate the influence of phase transition temperature (Tm) on the properties of TSL. High temperature triggered TSL (HTSL), low temperature triggered TSL (LTSL) and non-TSL (NTSL) were prepared and temperature sensitive release properties were extensively compared in different media. Mouse plasma was determined to have similar effect on the release profiles compared to human plasma, in which complete release were obtained at 38 °C and 40 °C for LTSL and HTSL, respectively. The temperature at which complete release achieved was found to be obviously lower than Tm. Brucine, an antitumor alkaloid, was encapsulated into different TSLs. After HT treatment, the viabilities of SMMC 7721 cells were determined to be 21.3±3.8% and 16.8±3.3% for 127 µM brucine LTSL and HTSL, respectively. Treating the tumor-bearing mice with LTSL, HTSL and NTSL led to significantly increased brucine uptake in the heated tumor site compared to the brucine solution group by 2.30, 3.80 and 2.26-fold, respectively. The results of this study suggested that Tm of TSL should be increased to obtain improved drug delivery efficiency to tumor.