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Objective@#To determine the clinical problems and outcome indicators that need to be included in the expert consensus of 5-aminolevulinic acid (ALA) photodynamic therapy in the treatment of oral potential malignant diseases. @*Methods@# Based on the relevant literature, the clinical problems and outcome indicators were drafted during the meeting. The Delphi method was used for expert consultation and expert opinion collection. The average and standard deviation of the voting results were calculated to determine the importance of the indicators, and the positive coefficient, variation coefficient and coordination coefficient were calculated for quality control. @* Results@#In the first round of the Delphi method, 12 outcome indicators (the main reference elements include photon integral flux, power density, illumination time, and spot diameter were identified; the specific parameters are photon integral flux of 100 J/cm2 and power density of 100-600 mW/cm2. A diode laser of (630 ± 5) nm wavelength should be chosen. The analgesic regimen is local anesthesia supplemented by hypothermia and intermittent laser irradiation before treatment. Lesions with hyperkeratotic require pretreatment. The concentration of ALA administered was set at 20%. Eight clinical problems (main reference elements of photodynamic irradiation dose, specific parameters, choice of light source, evaluation criteria of efficacy, prevention of adverse effects, dosing concentration, whether oral potentially malignant diseases with hyperkeratosis should be pretreated, administration of photosensitizers) were included according to the literature and expert discussion. In the second round, 89 experts completed the questionnaire and gave very important evaluations of 9 outcome indicators (the main reference elements included photon integral flux, power density and illumination time; the specific parameters were a photon integral flux of 100 J/cm 2 and a power density of 100-600 mW/cm2). A diode laser of (630 ± 5)nm wavelength should be chosen. The concentration of ALA administered was set at 20%. Six clinical problems (main reference elements of photodynamic irradiation dose, specific parameters, choice of light source, evaluation criteria of efficacy, dosing concentration, administration of photosensitizers), and the remaining 3 were given important evaluations, with good consistency.@*Conclusion@# In this study, the irradiation dose, mode of administration and concentration, evaluation criteria of efficacy, prevention of adverse effects and pretreatment regimen of ALA photodynamic therapy for oral potentially malignant diseases determined by the Delphi method had good agreement among experts.
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Objective To investigate radioactive nuclide 210Po content in the diet of residents and internal irradiation dose caused by them. Methods The major food distribution market is selected, more than 50 kinds of food samples such as meat, vegetables, fruits, aquatic products, cereals, milk are collected, the combined method ofwet ashingand metal deposition is used to measure 210Po content of food samples, and analysis of monitoring data and estimationof irradiationexposure dose of residents caused by 210Po and their relative contribution are made. Results In the food samples, the specific activity of 210Po was 8.34 mBq/kg· fresh～16.9 Bq/kg· fresh, and the content of 210Po in hairtail was higher, its value was16.9 Bq/kg· fresh, which was higher than other freshwater fish. According to the data, the annual intake of residents was 108 Bq/person, and the annual effective dose of adult caused by 210Po was 129 μSv/a.The relatively large contribution were from flour (15.2%), eggs (22.0%), aquatic products (17.1%) and vegetable oil (18.1%). Conclusion The annual intake of 210Po for residents is lower than the current limit for adults of which the value is 2 200 Bq.
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Objective@#To evaluated the unplanned coverage dose to the internal mammary chain (IMC) in patient treated with postmastectomy radiotherapy (PMRT).@*Methods@#One hundred and thirty eight patients with breast cancer receiving radiotherapy (RT) in our hospital were retrospectively analyzed. Patients were divided into three groups: three-dimensional conformal radiotherapy (3D-CRT) group, forward intensity-modulated radiotherapy (F-IMRT) group and inverse IMRT (I-IMRT) group. The IMC were contoured according to Radiation Therapy Oncology Group (RTOG) consensus, and were not include into the planning target volume (PTV). The incidental irradiation dose to IMC among the three groups and the first three intercostal spaces IMC (ICS-IMC 1-3) were all compared, and explored the relationship between the mean doses (Dmean) of IMC and the OARs (ipsilateral lung and heart).@*Results@#The dose delivered to IMC showed no difference in CRT, F-IMRT and I-IMRT(33.80 Gy, 29.65 Gy and 32.95 Gy). And 10.42%, 2.04%, and 9.76% patients achieved ≥45 Gy when treated with CRT, F-IMRT and I-IMRT. For the IMC dose in the first three intercostal spaces (ICS1-3), there was no difference to the three treatment plannings. The Dmean, V20, V30, V40 and V50 of the ICS-IMC2 and ICS-IMC3 were all obviously superior than ICS-IMC1 for all these three plannings. Moderate positive correlation was founded between Dmean for IMC and Dmean for heart for left breast cancer patients underwent CRT (r=0.338, P=0.01). Whereas for F-IMRT and I-IMRT groups, positive correlation were founded between Dmean for IMC and Dmean and V20 for ipsilateral lung for all patients (F-IMRT: r=0.366, P=0.010; r=0.318, P=0.026; I-IMRT: r=0.427, P=0.005; r=0.411, P=0.008).@*Conclusions@#In 3D-CRT, F-IMRT and I-IMRT planning methods, partial patients get IMC irradiated doses that could achieve therapeutic doses. Compared with 3D-CRT, F-IMRT and I-IMRT further reduced the dose of irradiated organs. However, there is no difference in the dose coverage of IMC for the three planned approaches when the IMC made an unplanned target.
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Objective To measure the irradiation doses from the image beam line (IBL) of Artiste linac under the 2Dplanar,MV CBCT,6 MV 2Dplanar and Somatom CT modes to select an appropriate image-guided mode combined with the irradiation sites. Methods The head, chest and pelvic phantom doses from the IBL under the 2Dplanar,MV CBCT and 6 MV 2Dplanar modes were measured by using IBA Dose 1 electrometer and FC65 ionization chamber.The irradiation doses of Somatom CT scans of the head, chest and pelvis were measured using IBA Dosimax plus A system and the measurement results were analyzed. Results In the head and neck, the average irradiation dose was 16. 60 mGy under IBL 2Dplanar mode, 58. 73 mGy under IBL MV CBCT mode, 19. 83 mGy under 6 MV 2Dplanar mode and 7-9 mGy under Somatom CT. In the chest, the average irradiation dose was 14. 08 mGy under IBL 2Dplanar mode, 49. 17 mGy under MV CBCT mode, 18. 97 mGy under 6 MV 2Dplanar mode and 9-11 mGy under Somatom CT mode.In the pelvis, the average irradiation dose was 13. 36 mGy under IBL 2Dplanar mode, 45. 65 mGy under MV CBCT mode, 17. 52 mGy under 6 MV 2Dplanar mode and 12-15 mGy under Somatom CT mode. Conclusions In the head and neck, the image quality under IBL 2Dplanar mode is recommended, which is qualified for image registration standards. Somatom CT mode is suitable for the chest. In the pelvic region, IBL 2DPlanar mode can be applied when the intestinal cavity and bladder are well filled, and MV CBCT mode can be chosen if they are poorly filled.
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Objective An optimal radiation dose was made research on tumor cells to develop effective tumor fusion vaccines. Methods We used the RS 2000 biological X-ray radiation instrument to produce different dose of X-rays.Mouse liver cancer cells line,BNL 1ME a.7R.1(MEAR),was used for experiment.The RS 2000 biological X-ray radiation was applied to create different tumor cell clones,which could help us to study the rela-tionship between irradiation dose and tumor cells′proliferation activity.Furthermore,the fusion cells′anti-tumor ef-fect was examined by flow cytometry. Results High-dose radiation would induce the lower proliferation of cancer cells than low-dose irradiation do.Conclusions During the preparation of fusion vaccines,irradiation dose should be considered as a factor that would influence the tumor cells′ proliferation activity. When the dose of irradiation was appropriate,we could make safe and efficient integration cell vaccines.
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Objective To investigate the effect of respiratory motion on inadvertent irradiation dose (ⅡD)to the microscopic disease(MD)and expanding margin of target volume in stereotactic body radiotherapy for lung cancer. Methods Based on the pattern of respiration-induced tumor motion during lung radiotherapy, a probability model of MD entry into or exit from internal target volume(ITV)was established and the theoretical dose to MD was calculated according to the static dose distribution by four-dimensional computed tomography. The experimental dose to MD during respiratory motion was measured using a respiration simulation phantom and optically stimulated luminescence(OSL)and then compared with the theoretical value for model validation.Results For the target volume in periodic motion,the deviation of the theoretical dose to MD from the experimental value measured by OSL was less than 5%. A 10-mm margin around ITV received a biological dose higher than 80 Gy. Conclusions The dose model established in this study can accurately predict the irradiation dose to MD in the target volume in periodic motion. Respiratory motion increases ⅡD to MD and there is no need to expand clinical target volume.
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PURPOSE: To investigate the caspase-3 expression in the acinar and ductal cells of rat submandibular glands after the irradiation of various doses. MATERIALS AND METHODS: The male Sprague-Dawley rats weighing approximately 250 gm were used for this study. The experimental group was irradiated with a single absorbed dose of 2, 5, 10, and 15 Gy on the head and neck region. The rats were sacrificed on the 1st, 3rd, 7th, 14th, 21st, and 28th day after irradiation. The specimens including the submandibular gland were sectioned and observed using histopathological and immunohistochemical methods. RESULTS: The local destruction of the acinar and ductal cells and the karyopyknotic nuclei of the acinar cells were observed in the 2 Gy and 5 Gy irradiation groups later than in the 10 Gy and 15 Gy irradiation groups. And the expression of caspase-3 was prominent only in the ductal cells in the 2 Gy and 5 Gy irradiation groups. CONCLUSION: This experiment suggests that radiation-induced apoptosis in the ductal cells of rat submandibular glands was induced by a low dose radiation associated with the activation of caspase-3 and radiation-induced necrosis was induced by a high dose radiation.
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Animals , Humans , Male , Rats , Acinar Cells , Apoptosis , Caspase 3 , Head , Neck , Necrosis , Rats, Sprague-Dawley , Submandibular GlandABSTRACT