At present, the main treatment for recurrent nasopharyngeal carcinoma (rNPC) is re-irradiation. Conventional external irradiation can result in a high incidence of side effects. Intensity modulated radiation therapy and stereotactic radiotherapy can not only reduce the radiation dose to vital organs and surrounding normal tissues, but also improve local control rate. Brachytherapy and surgery are also shown to be effective in early diseases.

Early diagnosis,early treatment and the correct therapeutic approch are the keys for metastatic nasopharyngeal carcinoma(NPC) treatment.Currently,PET-CT is the best modality for distant metastasis staging of NPC.Cispalatin-based chemotherapy is the standard treatment method of metastatic NPC.Molecular targeted therapy is possible to further increase curative effect.When the lesions are limited,local palliative treatment may improve prognosis if patient's illness is controled by chemotherapy.

90% with better sparing of the surrounded normal tissue.However,the metastasis rate is still 20%-25%,which limits the improvement of overall survival(OS).To consolidate the local control rate and reduce the metastasis rate,it is necessary to combine chemotherapy with radiotherapy.According to clinical randomized studies and meta-analysis,chemotherapy can improve the OS of loco-regionally advanced nasopharyngeal carcinoma by more than 6% with radiotherapy alone as baseline.Concurrent chemo-radiotherapy is the most promising strategy to cope with the disease.This review has summarized the progress in the area of combination of chemotherapy and radiotherapy for the treatment of loco-regionally advanced nasopharyngeal carcinoma.

Objective To study the radiosensitization of histone deaeetylases inhibitor(HDACI) panobinistat in prostate cancer cells in vitro,as well as the possible mechanisms.Methods IC20 of two prostate cancer cell lines(LNCaP and PC-3)was determined using MTI assay.Cells received a single dose irradiation of 0,2,4,6,or 8 Gy using 6 MV X-ray for radiosensitivity experiment,but only 2 Gy for western blot and flow cytometry.Radiosensitization of panobinostat was investigated with clonogenic assay,and sensitizing enhancement ratio(SER)was calculated with single-hit multi-target model.Western blot was used to compare γH2AX expression.Flowcytomctry was used to detect the cell cycle distribution.Results IC20 of LNCaP and PC-3 was 2.5 and 10.0 μmol/L,respectively.SER of panobinostat at IC20 was 1.37(D0 ratio)and 1.11(Dq ratio)for LNCaP cells,and 1.78(D0 ratio)and 1.17(Dq ratio)for PC-3 cells.Expression of γH2AX gradually decreased in the 2 Gy irradiation-alone cells standing for the DSB repair,while γH2AX expression was persistent in the combination group.Irradiation triggered a G2/M arrest 6-12 hours after irradiation in LNCaP and PC-3 cells.G2/M arrest was observed when cells were treated with panobinostat for 24 hours,however,no significant change concerning cell cycle distribution was showed when cells received further irradiation.Conclusions Panobinostat Call radiosensitize prostate cancer cells,which may be related with increased DNA DSB,inhibition of DSB repair and attenuation of cell cycle modulation after irradiation.

Local recurrent nasopharyngeal carcinoma(NPC) presents a troublesome challenge to radiation oncologist. Reirradiation is the primary modality nowadays. However, clinical data on reirradiation are still relatively scarce. This article summarized the treatment advances and the clinical characteristics associated with relapse of NPC, and reviewed the outcomes of different radiation techniques in the management of recurrence of NPC, i.e. conventionalradiotherapy, stereotactic radiotherapy, brachytherapy, three-dimensional conformal radiotherapy and intensity modulate radiotherapy, or some combination of above in recent years.

Objective To re-evaluate the prognostic value of the 6th edition of UICC/AJCC staging system in patients with nasopharyngeal carcinoma (NPC) treated with intensity-medulated radiation therapy (IMRT). Methods From February 2001 to March 2007, Clinical data of 570 NPC patients initially treated with IMRT in Cancer Center of Sun yat-sen University were reviewed and the long-term survival was analyzed according to T, N and overall stages. Results The median follow-up was 42 months. 184 patients were followed up to 5 years. The 5-year local recurrence-free survival (LRFS), distant metastasis-free survival (DMFS) and overall survival (OS) of the whole group were 93. 0%, 85.4% and 83. 3% ,respectively. No statistically significant difference of LRFS was detected between the either two of stage T_1, T_(2a) and T_(2b)(100%, 100% and 94. 5% ;T_1 vs. T_(2b), χ~2 = 1.92, P =0. 166 ;T_(2a) vs. T_(2b), χ~2= 0. 35, P =0. 555), stage T_(2b) and T_3 (94. 5% and 91.3% ;χ~2 = 2. 62, P = 0. 106), or stage T_3 and T_4 (91.3% and 89. 5% ; χ~2 = 1.55, P =0. 214). The 5-year DMFS of stage N_2 was similar with stage N_1 or stage N_3(80. 2%, 86. 2% and 61. 4% ; N_2 vs. N_1, χ~2=2.22, P=0.136;N_2 vs. N_3, χ~2= 1.92, P=0.165). No statistically significant difference of 5-year OS was observed among stage Ⅰ , Ⅱ_a and Ⅱ_b(91.7%, 100% and 95. 3% ; Ⅰ vs. Ⅱ_b χ~2 =0.32, P=0.574;Ⅱ_a vs. Ⅱ_b,χ~2-0.25, P=0.617), or between Ⅳ. And Ⅳ_b(67.9% and 75. 0% ;χ~2 = 0.25, P = 0. 616). Conclusions The 6th edition of UICC/AJCC staging system shows poor predictive value for the long-term survival of NPC patients treated with IMRT.

Objective To evaluate the effect of intensity-modulated radiation therapy(IMRT) on parotid function in nasopharyngeal carcinoma(NPC). Methods Eighty-three NPC patients received prima-ry IMRT between 2001 and 2003. Xerostomia before radiotherapy, at the end of radiotherapy, at 6-month, 1-,2-,3-,4- and 5-year after radiotherapy were investigated, respectively. The relation between xerostomia and parotid dose distribution was analyzed. Results Of all the patients,4,31,31 and 17 had stage Ⅰ,Ⅱ,Ⅲ and ⅣA disease, respectively. Sixteen patients received chemo-radiotherapy. The median followed-up time was 65 months. The 5-year local control and regional control rate were 96% and 95% ,respectively. The 5-year overall survival rate was 80%. The mild xerostomia rate at the seven time points was 42%, 51%, 71%, 77%, 58%, 38% and 26%. The corresponding moderate xerostomia rate was 52%, 53%, 21%,8%, 3%, 2% and 2%, respectively. No serious xerostomia was observed. The mean dose of the bilateral parotid glands was 34.34 Gy. Xerostomia at 6-month after radiotherapy was positively correlated with the mean dose of the parotid glands, and D50 was the independent factor in predicting the xerostomia. Parotid function was well protected when the mean dose and D50 were no more than 33 Gy and 29 Gy,respectively. Conclusions IMRT can improve the local-regional control of NPC and protect the parotid glands from radiation-induced in-jury.

Objective To evaluate the long-term efficaey of radiotherapy (RT) alone for nasopharyngnal eareinoma(NPC). Methods 934 NPC patients initially treated by conventional RT alone in 1999 were reviewed retrespeetively, including 676 males and 258 females. According to 92' Fuzhou staging system,there were 35 stage Ⅰ,215 stage Ⅱ ,488 stage Ⅲ and 196 stage Ⅳ diseases. All patients were treated by conventional RT alone with two opposing parallel faeio-eervical fields. The total dose delivered to the nasopharynx was 66-88 Gy. The dose to the cervical lymph nodes was 60-70 Gy, while the prophylactic dose to the neck was 50-56 Gy. Results The median follow-up was 67.1 months. The 5- and 8-year overall survival(OS), disease-free sutural, relapse-free survival and metastasis-free survival rates were 68.30%, 67.3% ,64.4% ,72.4% ,and 48.0% ,66.6% ,50.8% ,68.0% (χ2=49.74, P=0.000), respectively. For stage N1patients,the 5-and 8-year overall survival(OS) ,disease-free survival ,relapse-free survival and metastasis-free survival rates were significantly lower than those of stage NO patients [66.0% : 77.4% and 50.3%:59.8%(χ2=33.34,P=0.000);66.8%:76.1% and 66.1%:76.1%(χ2=29.08,P=0.000); 63.4%:72.9% and 48.9% : 58.7% (χ227.65,P=0.000);71.0%:80.8% and 63.4%:68.0%(χ2=26.13,P=0.000)]. And the corresponding rates of stage N<1-2>were significantly higher than stage N3,while no statistical difference was observed between stage N1 and N2. Multivariate analysis showed that sex, age, pathology,T stage and N stage were independent prognisitie factors for OS. Conclusions Radical RT alone could obtain good long-term results in early stage NPC. Tlowever,OS for local-regionally advanced stage NPC was still unsatisfactory because of the high relapse and metastatic rate. Clinical stage and N stage were valuable prognostic factors.

Objective To detect the distribution of mesenchymal stem cells(MSCs) after total-body irradiation in rats. Methods MSCs were cultured and labeled with green fluorescent protein(GFP). Rats were exposed to total-body irradiation(TB1) or TBI plus total brain irradiation, and then MSCs were injected through the tail vein. The Fluorescent MSCs were observed by fluorescence microscope. The MSCs numbers in different organs were determined by quantitative RT-PCR method. Results GFP-labeled MSCs were ob-tained. After MSCs were infused to the rats,few of them were observed in the organs of nonirradiated group except for a very low number in the lungs,bone marrow(BM) and spleen. TBI of 6 Gy increased the engraft-ment of MSCs in almost all the organs, especially in early response tissues such as the small intestine and BM. TBI of 7 Gy further increased the number of MSCs. The MSCs numbers in the brain and other organs were significantly increased after 20 Gy total brain irradiation in addition to 6 Gy TBI. Conclusions Radi-ation injury can induce the aggregation of MSCs. With the increase of radiation dose and severity of radiation injury,a significant increase of MSCs in different organs were observed. Local irradiation can increase the MSCs distribution in the radiation field as well as other organs.

Objective To retrospectively analyze the influence of intensity-modulated radiotherapy (IMRT) on tumor regression in primary nasopharyngeal carcinoma (NPC).Methods 272 patients with NPC received radical radiotherapy alone,196 by IMRT with a total treatment time of 6 weeks,and 76 by bilateral field conventional radiotherapy (CRT) with the total treatment timc of 7 weeks.Results By the end of radiotherapy,the primary tumor and neck lymph node residual rates of the IMRT group were 36.7％ and 44.2％,respectively,both significantly higher than those of the GRT group (21.1％ and 26.6％,x2 =6.15,3.99,P ＜ 0.05).Three months after the radiotherapy,residual lesions were observed at the nasopharynx or neck lymph nodes in 12 of the IMRT group,with a residual rate of 6.1％,not significantly different from that of the CRT group (9.2％,7/76).The 12 residual lesions of the IMRT group all vanished completely 4 -9 months after the radiotherapy.Conclusions There is an obvious difference in regressive mode between IMRT and CRT technique in NPC treatment.At the end of IMRT,the tumor residual rate is slightly increased.However,the delivered dose of gross tumor volume (GTV) is sufficient,and the boost dose should not be delivered indiscreetly.