ABSTRACT
Objective To evaluate the dose distribution in clinical target volume (CTV) and organs-at-risk (OARs) in three dimension therapy plans in patients with squamous cell carcinoma of tongue receiving postoperative intensity-modulated radiotherapy (IMRT) or conventional radiotherapy (CRT) by dosimetric study. Methods Thirty-five patients with squamous cell carcinoma of tongue were divided into CRT group(n=17) and IMRT group(n=18). All patients underwent head-and-neck immobilization with a thermoplastic mask and planning CT scan, and target volume and OARs were contoured. Dose calculation and plan optimization were performed. All three dimension plans passed quality assurance before treatment. The dosimetry of therapy plans with IMRT or CRT in target volume and OARs dose distribution was compared by dose-volume histogram (DVH), conformity index (CI) and homogeneous index (HI). Results There were significant differences in D95 (isodose line to cover 95 percent target volume), CI, HI, minimum dose and maximum dose in CTV of therapy plans between patients with IMRT and CRT(P < 0.01), and there was no significant difference in mean dose of CTV(P > 0.05). The radiation dose on salivary glands (both parotid glands and contralateral submandibular gland) in patients with IMRT was significantly lower than that in patients with CRT(P < 0.01). Conclusion Compared with dose distribution of CRT plans, there are more advantages in improving dose distribution at the target volume and sparing salivary glands in IMRT therapy plans in patients with squamous cell carcinoma of tongue.
ABSTRACT
<p><b>OBJECTIVE</b>The purpose of this study was to invest the effect of epidermal growth factor receptor monoclonal antibody MAb225 on radiosensitivity of tongue squamous cell carcinoma cell Tca8113.</p><p><b>METHODS</b>Tca8113 cells were treated with different concentrations of MAb225. Radiation dose survival curve was generated from clonogenic survival assay. SERPD0 and survival faction (SF2) was analysed by single hit multi-target (SHMT) radiobiological model using RADMEDIC software. Nude mice with Tca8113 tumor xenografts were treated with MAb225, radiation treatment or both of them. Tumor responses were assessed by tumor growth delay, and t test was used for statistical analysis.</p><p><b>RESULTS</b>MAb225 enhanced the radiosensitivity of Tca8113 cells. SERD0 of Tca8113 cells treated with 0.5 mg/L MAb225 was 1.23. The survival fraction of cells treated with MAb225 was significantly decreased. Tumor radioresponse could be enhanced by MAb225 (P < 0.05).</p><p><b>CONCLUSION</b>MAb225 could enhance radiosensitivity of tongue squamous cell carcinoma cell.</p>
Subject(s)
Animals , Humans , Mice , Antibodies, Monoclonal , Carcinoma, Squamous Cell , Mice, Nude , Radiation Tolerance , Tongue NeoplasmsABSTRACT
<p><b>OBJECTIVE</b>To study the influence of radiotherapy on immediate reconstruction with the titanium plate after resection of mandible in oral cancer patients.</p><p><b>METHODS</b>Fifty-eight cases (radiation group, 30 patients and control group, 28 patients) with titanium plate for immediate reconstruction of mandibular defects were observed from January, 1997 to May, 2002. The patients of radiation group underwent radiotherapy with total doses of 4,050 - 6,540 cGy (mean 5,495 cGy). The titanium plate was in radiation fields and was irradiated during the radiation therapy.</p><p><b>RESULTS</b>Local infection and fistula accounted for 6 cases and plate exposure accounted for 5 in radiation group. Local infection and plate exposure happened in 4 and 3 patients in control group respectively. Titanium plates were taken in six cases in radiation group and 4 cases in control group by re-surgery 4 - 15 months after primary surgery because of local infection. The success rates of immediate reconstruction with the titanium plate were 80.0% (24/30) in radiation group and 85.7% (24/28) in control group (P > 0.05).</p><p><b>CONCLUSIONS</b>The cases of immediate reconstruction with the titanium plate after resection of mandible in oral cancer patients can accept postoperative radiotherapy.</p>