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Objective:To investigate the implementation procedures and dosimetric verification of the first patient treated with total body irradiation (TBI) based on volumetric modulated arc therapy (VMAT).Methods:Two sets of CT images were acquired under the head-in first and foot-in first to contour the planning target volume (PTV) of the cranial and caudal segments to accomplish the treatment of the whole body length, on which two interrelated plans of 5 subsequent isocenters with a total of 15 VMAT fields were performed to cover all PTVs. The plans were prescribed to ensure 90% PTV dose coverage with a total dose of 12 Gy in 6 fractions. Firstly, a dose optimization was performed on the caudal CT images, then the cranial CT images were optimized based on the dose distribution of the caudal CT images. The evaluation of the final treatment plan was carried out based on a plan sum of both two sets of images. The parameters of PTV and organs at risk (OARs) were measured by dose volume histograms from the accumulated plan. The quality assurance comprised the verification of the VMAT plans for each individual isocenter via Delta4 phantom. The dose distribution in the overlapped region between two adjacent central fields was verified with EBT3 film. The absolute dose at the overlapped region between two images was measured via Pinpoint chamber. In vivo dosimetry on the patient′s skin was monitored by MOSFET dosimeters. The results of planning parameters and treatment duration were analyzed. Results:The mean doses of two segments of PTVs were 12.45 Gy and 12.37 Gy. The mean dose for the lung was 10.8 Gy. The machine unit (MU) and mean treatment delivery time were 2 883 MU and 24.3 min, and the mean total time per fraction was 121 min. The mean 3%/3 mmγ-analysis pass rate for each isocenter VMAT plan was (99.74±0.42)%, and the mean 5%/5 mmγ-analysis pass rate for the overlapped region was (90.11±2.72)%. The average deviation of absolute dose in the overlap region of the caudal and cranial images was (3.6±0.4)%. In vivo measurement of 8 points on the patient showed that the dose of each region was ranged from 1.57 Gy to 2.04 Gy. Conclusion:According to the results of dosimetric verification, TBI based on multi-isocenter VMAT can be applied in clinical practice, which remains to be improved in terms of dose distribution, measurement results and clinical efficiency.
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Objective: Date palm seed extract (DPSE) has various compounds revealing antioxidant features. This study aimed to evaluate the radioprotective effect of DPSE in total body gamma irradiation. Materials and Methods: At first, chemical characteristics of DPSE were analyzed by ultraviolet, visible and Fourier transform infrared spectroscopy. Then, the toxicity of DPSE was assessed. For this purpose, 60 mice were divided into five groups, and each of the groups were injected by the doses of 100, 200, 300, 400, and 500 mg/kg, respectively. At the termination of the experiment, mortality rate and weight loss of all mice were evaluated over a period of 30 days. Finally, the radioprotective effect of DPSE was evaluated by dividing 36 mice into three groups: control, test, and placebo and then were irradiated by Cobalt-60. Results: According to the findings, there was no mortality due to DPSE. Furthermore, for the maximum dose of 500 mg/kg, the number of mice surviving at the termination of the experiment with and without injection of DPSE was reported as 83% and 41%, respectively. In addition, a significant difference was obtained between radiated mice with and without DPSE injection (P = 0.035). Conclusion: The findings showed that DPSE injected into mice before irradiation has no toxicity and could protect mice from lethal effects of total body irradiation. The use of DPSE as a new radioprotector agent in the human needs further studies, particularly clinical trials
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Objective To explore the feasibility of application of the Monte Carlo method to simulate the whole body dose distribution in patients with total body X (γ) ray irradiation by comparing the actual measurement results.Methods A Monte Carlo model of a 6 MV Elekta Synergy Clinical linear accelerator was established by MCNPX.According to the relationship between the CT value and the density of the material,the CT of the ATOM physical phantom was converted into a voxel phantom for MCNPX calculation.The dose distribution of the whole body was simulated in the total body X (γ) ray irradiation.The simulated results were compared with the measurement values of the thermoluminescence dosimetry at different positions in the ATOM physical phantom to analyze the differences.Results The difference between the depth dose curve and the off-axis dose curve and the actual measurement values calculated by the 6 MV accelerator treatment head model in the water tank was less than 2％,with the maximum dose depth of approximately 1.5 cm and field size of 10 cm× 10 cm,which were consistent with the actual measurement values.The maximum difference between the simulated results at different locations in the body and the thermoluminescence dosimeter was approximately 4％,and the simulated results of MCNPX were almost in good agreement with the results of thermoluminescence.Conclusions The whole body dose distribution in patient with total body X (γ) ray irradiation can be accurately simulated by MCNPX.Monte Carlo simulation makes it possible to optimize the uniformity of the total body dose during the total body irradiation process.
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Objective@#To investigate the dosimetric differences between TomoDirect (TD) and Helical Tomotherapy (HT) in total body irradiation (TBI), as well to evaluate the plan quality and delivery efficiency of TD.@*Methods@#Eight patients with acute leukemia at an average height of about 120 cm who had undergone TBI in the first affiliated hospital of Zhengzhou university were retrospectively reviewed and replanned with the TD and HT techniques for dosimetric comparison. Identical planning parameters were configured for both techniques except that TD plans were designed with 2-12 equally spaced odd number fields and with an initial angle of 180 or 0 degree. Dosimetric differences in mean dose of plan target volume (PTVDmean), homogeneity index (HI), dose of organs at risk (OARs), as well as delivery time were compared between the TD and HT plans.@*Results@#The TD plans with 9 fields or more had similar PTVDmeanand HI compared with HT plans, while TD plans with less than 9 fields had a significant different PTVDmean(t=-3.12, -5.41, -20.33, -4.56, -7.22, -11.27, P<0.05) and HI (t=-2.94, -5.18, -15.66, -4.31, -5.51, - 9.13, P<0.05) compared with those of HT. In terms of OARs, the TD plans with 7 fields or more had no significant dosimetric differences in the mean dose of left and right lung compared with the HT plans. The TD plans with 3 fields had significant different maximum dose in the left lens plan risk volume(PRV) (2.14±0.60) Gy and the right lens PRV (3.05±0.10) Gy (t=0.77, 0.63, P<0.05) compared with the HT plans. No significant difference in delivery time was observed. The initial angle of the TD plans had no effects on PTVDmean, HI, OAR dosimetry and delivery time.@*Conclusions@#The TD plans with 9 fields or more can achieve similar plan quality in terms of target coverage, OAR sparing and delivery time, but have an advantage in the maximum dose to lens PRV compared with the HT plans.
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Objective@#To investigate the efficacy of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in the treatment of leukemia patients also suffering from central nervous system leukemia (CNSL) .@*Methods@#A total of 48 leukemia patients with central nervous system leukemia admitted to our hospital from May 2012 to December 2017 were retrospectively analyzed.@*Results@#① Including 22 cases of acute lymphocytic leukemia (ALL) , 21 cases of acute myeloid leukemia (AML) , and 5 cases of chronic myelogenous leukemia (CML) . Before transplantation, 19 patients achieved complete remission (CR) , and the rest 29 ones without remission. ②The conditioning regimen used TBI as the main protocol, and 6 patients were combined with whole brain and total spinal cord radiotherapy, 2 with Cyber knife treatment, and children with modified IDA combined with BUCY. ③All 48 patients were successfully transplanted, the median time for leukocyte engraftment was 14 (10-23) days, the median time for platelet transplant 16 (6-78) days. ④Bone marrow was evaluated 28 days after transplantation, all 48 patients reached CR, and DNA testing confirmed that they were all full donor chimerism. ⑤The median follow-up was 14 (2-69) months. Of them, 28 cases survived, 10 relapsed and the rest 3 had recurrence of CNSL after transplantation. One year after allo-HSCT, the overall survival (OS) of CR and non-CR groups were (77.3±10.0) % and (57.6±9.3) % (P=0.409) , respectively, the disease-free survival rates (DFS) were (71.2±11.0) % and (53.9±9.5) % (P=0.386) , respectively. The 1-year OS rates of ALL and AML groups after transplantation were (54.2±10.7) %, (80.1±8.9) %, respectively (P=0.200) , and DFS rates were (49.2±10.8) %, (75.0±9.7) % (P=0.190) , respectively.@*Conclusion@#Allo-HSCT was safe and effective for leukemia patients with CNSL.
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Objective To investigate the dosimetric differences between TomoDirect ( TD) and Helical Tomotherapy ( HT ) in total body irradiation ( TBI ) , as well to evaluate the plan quality and delivery efficiency of TD. Methods Eight patients with acute leukemia at an average height of about 120 cm who had undergone TBI in the first affiliated hospital of Zhengzhou university were retrospectively reviewed and replanned with the TD and HT techniques for dosimetric comparison. Identical planning parameters were configured for both techniques except that TD plans were designed with 2-12 equally spaced odd number fields and with an initial angle of 180 or 0 degree. Dosimetric differences in mean dose of plan target volume ( PTVDmean ) , homogeneity index ( HI) , dose of organs at risk ( OARs) , as well as delivery time were compared between the TD and HT plans. Results The TD plans with 9 fields or more had similar PTVDmean and HI compared with HT plans, while TD plans with less than 9 fields had a significant different PTVDmean(t=-3. 12, -5. 41, -20. 33, -4. 56, -7. 22, -11. 27, P<0. 05) and HI ( t=-2. 94, -5. 18,-15. 66,-4. 31,-5. 51,- 9. 13, P<0. 05) compared with those of HT. In terms of OARs, the TD plans with 7 fields or more had no significant dosimetric differences in the mean dose of left and right lung compared with the HT plans. The TD plans with 3 fields had significant different maximum dose in the left lens plan risk volume(PRV) (2.14±0.60) Gy and the right lens PRV (3.05±0.10) Gy (t=0.77, 0.63, P<0.05) compared with the HT plans. No significant difference in delivery time was observed. The initial angle of the TD plans had no effects on PTVDmean , HI, OAR dosimetry and delivery time. Conclusions The TD plans with 9 fields or more can achieve similar plan quality in terms of target coverage, OAR sparing and delivery time, but have an advantage in the maximum dose to lens PRV compared with the HT plans.
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Objective To evaluate the feasibility of total marrow and lymphatic irradiation (TMLI)with helical tomotherapy as a conditioning regimen before hematopoietic stem cell transplantation (HSCT).Methods Seven children with acute lymphoblastic leukemia and aplastic anemia were recruited as study subjects.The median age was 7 years old.The prescribed dose was 12 Gy/6 fractions twice daily.The exposure dose of the target and the organs at risk between helical helical tomotherapy-based TMLI regimen and total body irradiation (TBI) regimen were statistically compared,and acute toxicity grading was performed for all patients.Results Compared with the TBI regimen,the average exposure dose reduction for organs at risk after the TMLI regimen was ranged from 4.2％ to 40.6％.The average exposure dose reduction for the kidney was the largest among all organs.The acute toxicities experienced by all patients were graded and recorded including 2 cases of nausea,5 cases of vomiting,1 case of anorexia,1 case of eryhema,3 cases of diarrhea,and 1 case of oral mucositis.Only grade 1-2 toxicities were observed,and no grade 3-4 toxicities occurred.Conclusions The findings in this study confirm the feasibility of helical helical tomotherapy-based TMLI regimen.Compared with the TBI regimen,the mean duration of treatment for the TMLI regimen with an equivalent dose is not increased.The exposure dose experienced by organs at risk is reduced and the predicted incidence rate is decreased when the TMLI regimen is employed,which provides a myeloablative pretreatment strategy.However,the long-term toxicity of TMLI regime remains to be evaluated by clinical trials.
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Objective To investigate the optimal distance between upper and lower target volumes and their correlated planning parameters by analyzing the dose distribution in the abutment regions during total body irradiation ( TBI) using helical tomotherapy. Methods A total of 10 patients with acute leukemia and with a height around 120 cm were enrolled. All patients were scanned by a Siemens simulation computerized tomography (CT) at a slice thickness of 5 mm. A lead wire was placed 10. 0 cm above the patella as a marker of the separation boundary for the upper and lower target volumes. The delineations of target volumes and organs at risk ( OARs ) were performed in the Varian Eclipse 13. 5 workstation with targets shrunk beyond the separation boundary at different distances. After contours and CT images were transferred to HT workstation, treatment plans were designed with different field width (FW, 5. 0 cm/2. 5 cm/1. 0 cm) and pitch values (0. 430/0. 287) at a modulation factor of 1. 8. All the plans were optimized with a dose calculation grid of 0. 195 cm × 0. 195 cm and identical planning parameters. The correlation between treatment planning parameters and targets shrunk distances were investigated by analyzing the dose distributions in the abutment area. Results The study demonstrated that the dose distributions in the abutment area were influenced only by the field width parameters: when the gap distance between the upper and lower targets was 5. 0 cm, the optimal FW is 5. 0 cm;Similarly when the gap distances were 2. 0 cm and 1. 0 cm, and the optimal FW 2. 5 cm and 1. 0 cm, respectively. In another words, the dose distribution of the abutment region was optimal when the target gap distance was equal to FW. Pitch values did not affect the quality of dose distribution in the abutment region and the overall treatment time ratio. Overall treatment time was inversely related to the FW. Conclusions Consistent target distance and FW is helpful to improve the dose homogeneity in the abutment area during TBI with HT. Appropriate planning parameters is critical to balance the treatment efficacy and efficiency.
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Objective@#To explore the levels of IL-22 in thymus damaged by γ-ray total body irradiation (TBI), and to study the role of IL-22 in T cell reconstitution after thymic injury induced by TBI.@*Methods@#To induce thymic injury, mice were treated by sub-lethal TBI. Levels of intra-thymic and circulatory IL-22 were detected by using ELISA assay. Untreated mice were used as control. After receiving sub-lethal TBI, mice were intraperitoneally injected with PBS or recombinant mouse IL-22, which were marked as TBI+PBS or TBI+IL-22, respectively. Mice were monitored for counts of total thymic cells and circulatory white blood cells. Flow cytometry was applied to analyze percentages of thymic epithelial cells (TEC), thymocyte subsets and circulatory T cells. Real-time PCR assay was applied to analyze the mRNA expression levels of Foxn1, Ccl25, Aire and Dll4 in thymus.@*Results@#①Sub-lethal TBI treated mice expressed higher levels of intra-thymic and circulatory IL-22, compared with untreated ones (all P<0.05). ②After injection of recombinant IL-22, TBI+IL-22 mice had higher levels of intra-thymic IL-22 than TBI+PBS mice (all P<0.05). ③On day 14 after irradiation, real-time PCR assay showed that TBI+IL-22 mice had higher mRNA levels of Foxn1, Ccl25, Aire and Dll4 in thymus compared with TBI+PBS ones. Meanwhile, the TBI+IL-22 mice had higher counts of total thymic cells[(5.93±3.19)×106/ml vs (1.42±0.46)×106/ml, t=3.128, P=0.033] and circulatory white blood cells[(3.08±0.94)×106/ml vs (1.43±0.30)×106/ml, t=3.730, P=0.015] than those of TBI+PBS mice. Flow cytometry analysis indicated that TBI+IL-22 mice had higher counts of TEC and thymocytes than TBI+PBS mice on day 14 after irradiation (all P<0.05). On days 7 and 14 after irradiation, TBI+IL-22 mice had higher counts of circulatory white blood cells and T cells than TBI+PBS mice (all P<0.05).@*Conclusion@#Sub-lethal TBI induces upregulation of intra-thymic IL-22, and injecting of recombinant IL-22 increases level of IL-22 in thymus. Injecting of recombinant IL-22 improves recovery of TEC and increases numbers of thymocyte subsets and circulatory T cell after thymic injury.
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BACKGROUND: Total body irradiation (TBI) has been traditionally used as a conditioning regimen prior to hematopoietic stem cell transplantation (HSCT) in patients with pediatric leukemia. However, TBI can cause late sequelae such as growth impairment, cataract, hormone abnormalities, infertility, neurocognitive effects, and secondary malignancy in pediatric patients. METHODS: This single center retrospective study included 22 patients with acute lymphoblastic leukemia who were aged <18 years and underwent HSCT between May 1999 and December 2014; seven patients received a TBI-based regimen and 15 received a non-TBI regimen. RESULTS: The overall survival and event-free survival rates in the TBI group were not significantly different from those in the non-TBI group (overall survival rate 71% vs. 73%, respectively; P=0.906; event-free survival rate 71% vs. 73%, respectively P=0.923). CONCLUSION: Our results indicate that non-TBI conditioning regimens can be an alternative treatment option of the treatment of pediatric acute lymphoblastic leukemia undergoing HSCT.
Subject(s)
Child , Humans , Cataract , Disease-Free Survival , Hematopoietic Stem Cell Transplantation , Hematopoietic Stem Cells , Infertility , Leukemia , Precursor Cell Lymphoblastic Leukemia-Lymphoma , Retrospective Studies , Survival Rate , Whole-Body IrradiationABSTRACT
PURPOSE: Pulmonary toxicities, including infectious pneumonia (IP) and idiopathic pneumonia syndrome (IPS), are serious side effects of total body irradiation (TBI) used for myeloablative conditioning. This study aimed to evaluate clinical factors associated with IP and IPS following TBI. MATERIALS AND METHODS: Fifty-eight patients with hematologic malignancies who underwent TBI before allogeneic hematopoietic stem cell transplantation between 2005 and 2014 were reviewed. Most patients (91%) received 12 Gy in 1.5 Gy fractions twice a day. Pulmonary toxicities were diagnosed based on either radiographic evidence or reduced pulmonary function, and were subdivided into IP and IPS based on the presence or absence of concurrent infection. RESULTS: Pulmonary toxicities developed in 36 patients (62%); 16 (28%) had IP and 20 (34%) had IPS. IP was significantly associated with increased treatment-related mortality (p = 0.028) and decreased survival (p = 0.039). Multivariate analysis revealed that the risk of developing IPS was significantly higher in patients who received stem cells from a matched unrelated donor than from a matched sibling donor (p = 0.021; hazard ratio [HR] = 12.67; 95% confidence interval [CI], 1.46–110.30). Combining other conditioning agents with cyclophosphamide produced a higher tendency to develop IP (p = 0.064; HR = 6.19; 95% CI, 0.90–42.56). CONCLUSION: IP and IPS involve different risk factors and distinct pathogeneses that should be considered when planning treatments before and after TBI.
Subject(s)
Humans , Cyclophosphamide , Hematologic Neoplasms , Hematopoietic Stem Cell Transplantation , Mortality , Multivariate Analysis , Pneumonia , Risk Factors , Siblings , Stem Cell Transplantation , Stem Cells , Tissue Donors , Unrelated Donors , Whole-Body IrradiationABSTRACT
PURPOSE: Pulmonary toxicities, including infectious pneumonia (IP) and idiopathic pneumonia syndrome (IPS), are serious side effects of total body irradiation (TBI) used for myeloablative conditioning. This study aimed to evaluate clinical factors associated with IP and IPS following TBI. MATERIALS AND METHODS: Fifty-eight patients with hematologic malignancies who underwent TBI before allogeneic hematopoietic stem cell transplantation between 2005 and 2014 were reviewed. Most patients (91%) received 12 Gy in 1.5 Gy fractions twice a day. Pulmonary toxicities were diagnosed based on either radiographic evidence or reduced pulmonary function, and were subdivided into IP and IPS based on the presence or absence of concurrent infection. RESULTS: Pulmonary toxicities developed in 36 patients (62%); 16 (28%) had IP and 20 (34%) had IPS. IP was significantly associated with increased treatment-related mortality (p = 0.028) and decreased survival (p = 0.039). Multivariate analysis revealed that the risk of developing IPS was significantly higher in patients who received stem cells from a matched unrelated donor than from a matched sibling donor (p = 0.021; hazard ratio [HR] = 12.67; 95% confidence interval [CI], 1.46–110.30). Combining other conditioning agents with cyclophosphamide produced a higher tendency to develop IP (p = 0.064; HR = 6.19; 95% CI, 0.90–42.56). CONCLUSION: IP and IPS involve different risk factors and distinct pathogeneses that should be considered when planning treatments before and after TBI.
Subject(s)
Humans , Cyclophosphamide , Hematologic Neoplasms , Hematopoietic Stem Cell Transplantation , Mortality , Multivariate Analysis , Pneumonia , Risk Factors , Siblings , Stem Cell Transplantation , Stem Cells , Tissue Donors , Unrelated Donors , Whole-Body IrradiationABSTRACT
The kidney is one of the most radiosensitive organs in the abdominal cavity and is the dose-limiting structure in cancer patients receiving abdominal or total body irradiation. In the present study, the effect of coenzyme Q10 (CoQ10) on radiation nephropathy was evaluated in rats. A total of 72 rats were equally randomized into 4 groups: Control, CoQ10, irradiation with 10 Gy (RT) + placebo, or RT + CoQ10. The 2 RT groups received single 10 Gy of abdominal irradiation. The 2 CoQ10 groups were supplemented daily with 1 mL of soybean oil containing 10 mg/kg of CoQ10. The RT + placebo and control groups received same dose of soybean oil. After 24 weeks, laboratory and histopathologic findings were compared. The 2 RT groups showed significant increases in blood urea nitrogen (BUN) and creatinine levels and significant pathologic changes such as glomerulosclerosis and tubulointerstitial fibrosis. CoQ10 supplementation resulted in significant reductions of BUN and creatinine levels compared with the RT + placebo group (P < 0.001 and P = 0.038, respectively). CoQ10 treatment significantly attenuated glomerular and tubular changes of irradiated kidney in semiquantitative analysis (P < 0.001 for both). Administration of CoQ10 can alleviate the radiation-induced nephropathy.
Subject(s)
Animals , Humans , Rats , Abdominal Cavity , Blood Urea Nitrogen , Creatinine , Fibrosis , Kidney , Soybean Oil , Whole-Body IrradiationABSTRACT
BACKGROUND: Total body irradiation (TBI) has been traditionally used as a conditioning regimen prior to hematopoietic stem cell transplantation (HSCT) in patients with pediatric leukemia. However, TBI can cause late sequelae such as growth impairment, cataract, hormone abnormalities, infertility, neurocognitive effects, and secondary malignancy in pediatric patients.METHODS: This single center retrospective study included 22 patients with acute lymphoblastic leukemia who were aged <18 years and underwent HSCT between May 1999 and December 2014; seven patients received a TBI-based regimen and 15 received a non-TBI regimen.RESULTS: The overall survival and event-free survival rates in the TBI group were not significantly different from those in the non-TBI group (overall survival rate 71% vs. 73%, respectively; P=0.906; event-free survival rate 71% vs. 73%, respectively P=0.923).CONCLUSION: Our results indicate that non-TBI conditioning regimens can be an alternative treatment option of the treatment of pediatric acute lymphoblastic leukemia undergoing HSCT.
Subject(s)
Child , Humans , Cataract , Disease-Free Survival , Hematopoietic Stem Cell Transplantation , Hematopoietic Stem Cells , Infertility , Leukemia , Precursor Cell Lymphoblastic Leukemia-Lymphoma , Retrospective Studies , Survival Rate , Whole-Body IrradiationABSTRACT
Objective To investigate radiation-related human plasma metabolic features by using metabonomics method and to analyze relative metabolic pathway .Methods The plasma samples of 40 patients pre-and post-total body irradiation (TBI) from January 2012 to May 2014 were collected, and the effect of TBI on human plasma metabolites was studied by gas chromatography mass spectrometry ( GC-MS) , and the differential plasma metabolic features related to irradiation damage were screened . Results The levels of glucose, myristic acid, oxalic acid, 3-hydroxy butyric acid, urea, aspartic acid, valine, leucine, lysine and threonine in plasma were significantly (P<0.05) increased after TBI, while the levels of cholesterol, pyruvic acid, propionic acid, lactic acid, alanine, glycine, inositol, sorbitan, ethylene glycol and hypoxanthine were decreased drastically (P<0.05).Conclusions TBI could cause significant changes in the levels of human plasma metabolites including amino acid metabolism , glucose metabolism, lipid metabolism and so on.
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Objective To investigate the optimal distance between the upper and lower targets in the subsection total body irradiation(TBI)using helical tomotherapy,and to analyze the dose distribution of abutment regions. Methods A total of 8 patients with acute leukemia with a height of about 120 cm were involved in the study. All patients were scanned from the calvarium to the toe by computerized tomography (CT,Siemens)with a thickness of 5 mm,and a lead wire was placed at a point 10 cm above the patella as a marker of the boundary between the upper and lower targets. The delineation of target volumes and organs at risk(OAR)was performed in the Varian Eclipse 10.0 doctor workstation. The different distances between the lead wires and the boundary of the two targets were delineated, and images were transferred to the HT workstation to design the radiotherapy planning,including Jaw width(5 cm),modulation factor(1.8),and pitch(0.43). The plans were superimposed together, and then the dose distribution in abutment regions with different target gaps was analyzed to find the optimal distance. Results When the target gap was 5 cm, the dose distribution in abutment regions was satisfactory. However,the dose was obviously insufficient when the gap was more than 5 cm;the doses in abutment regions significantly exceeded the prescribed doses when the gap was less than 5 cm. Conclusions In the subsection TBI using HT, different parameters were designed,including Jaw width(5 cm), modulation factor(1.8), pitch(0.43), and slice thickness(5 mm). The upper and lower borders of the targets should be 2.5 cm away from the lead wire,that is,a gap of 5 cm,thus avoiding the dose-related hot or cold spots in the target convergence and ensuring a safer and more accurate radiotherapy.
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Objective To evaluate the efficiency of amifostine in protecting against oral and gastrointestinal mucositis in hematologic malignancies patients with high-dose total body irradiation following the hematopoietic stem cell transplantation,and assess the hematologic recovery as well as the potential side effect of amifostine.Methods Thirty-two hematologic malignancies patients underwent hematopoietic stem cell transplantation in our institution from 2012 to 2016 were retrospectively analyzed.All of them were treated with total body irradiation (700-1 200 cGy) and high-dose chemotherapy,in which 14 patients received 400 mg amifostine before radiotherapy.Prior institutional experience in 18 patients treated without amifostine was used as a historical comparison (no-amifostine group).Results Severe oral mucositis occurred in 14.3％ of patients in the amifostine group while 77.2％ in the no-amifostine group (x2 =10.62,P ＜0.05).Total parenteral nutrition was used in 21.4％ of amifostine group and 38.8％ in noamifostine group (P ＞ 0.05).The rates of grade 2 and 3 gastrointestinal mucositis were 35.7％ and 61.5％ in amifostine group,while in no-amifostine group the rates were 33.3％ and 66.7％,respectively (P ＞ 0.05).No significant difference was found in engraftnent times of granulocyte and platelet.No amifostine related side effects were observed.Conclusions The combination of amifostine and total body irradiation conditioning therapy during hematologic stem cell transplantation might reduce the severity of oral mucositis.The utilize of amifostine has no obvious effect on hematopoietic recovery and can be well tolerated.
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Objective To observe the protective effect of propofol on hematopoietic system injury in mice with total body irradiation (TBI). Method Three different radiation doses were used in the experiments: 7.5 Gy TBI in 30 day-survival experiment, 6Gy TBI in colony-forming unit spleen (CFU-S) experiment and 2Gy TBI in the other experiment; mice were divided into 4 groups in a 30 day-survival experiment, including 7.5Gy TBI group, 7.5 Gy TBI + 5 mg/kg propofol group, 7.5 Gy TBI + 10 mg/kg propofol group and 7.5 Gy TBI + 20 mg/kg propofol group. For the other experiments, mice were divided into 4 groups: control group, propofol group, TBI (2 or 6 Gy) group, and TBI + 20 mg/kg propofol group. Propofol of 20 mg/kg were administered to mice 1 d before TBI, 30 mins before TBI and once each day within the following 7 days after TBI. Mice were euthanized on the ninth day after TBI, the number of CFU-S, peripheral blood parameters and bone marrow cells per femur were measured in this experiment. Results Propofol improved the 30 day-survival of lethally irradiated mice. There were increases in number of CFU-S, white blood cells, red blood cells, hemoglobin in peripheral blood and bone marrow cells per femur in 2 Gy TBI + 20 mg/kg propofol group compared to 2 Gy TBI group (P<0.05). Conclusion Propofol exhibits a promising protective effect on TBI-induced hematopoietic system injury; further study should be focused on the related mechanisms.
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Objective To observe the protective effect of propofol on hematopoietic system injury in mice with total body irra?diation(TBI). Method Three different radiation doses were used in the experiments:7.5 Gy TBI in 30 day-survival experiment,6Gy TBI in colony-forming unit spleen(CFU-S)experiment and 2Gy TBI in the other experiment;mice were divided into 4 groups in a 30 day-survival experiment,including 7.5Gy TBI group,7.5 Gy TBI+5 mg/kg propofol group,7.5 Gy TBI+10 mg/kg propofol group and 7.5 Gy TBI + 20 mg/kg propofol group. For the other experiments,mice were divided into 4 groups:control group,propofol group,TBI(2 or 6 Gy)group,and TBI+20 mg/kg propofol group. Propofol of 20 mg/kg were administered to mice 1 d before TBI,30 mins before TBI and once each day within the following 7 days after TBI. Mice were euthanized on the ninth day after TBI,the number of CFU-S,peripheral blood parameters and bone marrow cells per femur were measured in this experiment. Results Propofol im?proved the 30 day-survival of lethally irradiated mice. There were increases in number of CFU-S,white blood cells,red blood cells, hemoglobin in peripheral blood and bone marrow cells per femur in 2 Gy TBI+20 mg/kg propofol group compared to 2 Gy TBI group (P<0.05). Conclusion Propofol exhibits a promising protective effect on TBI-induced hematopoietic system injury;further study should be focused on the related mechanisms.
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Objective To investigate an X-ray total body irradiation (TBI) technique using anterior-posterior opposed fields with patients at the side-lying position,and to analyze the real-time in vivo dosimetry results.Methods The accelerator with 10 MV X-rays of Varian Trilogy was used for the TBI with the extended source to skin distance of 390 cm.The percent depth dose,off axis factors and absolute dose output were measured.The dose accuracy and homogeneity was monitored real-time using multichannel diode dosimeter for 10 patients.The monitored sites included forehead,mandible,suprasternal fossae,xiphoid,umbilicus,pelvis,middle of thigh,knee,middle of leg and ankle.The patients were irradiated at the side-lying position,with the prescription dose of 1 200 cGy/6 f during 3 days,the middle line dose rate of 5.0 cGy/min.Solid water was used for the compensation of the dose homogeneity.Results The off axis dose homogeneity was less than ± 5.0％ for the TBI geometry.The absolute dose output was 0.072 1 cGy/MU at the maximum dose point.The total body irradiation was finished smoothly for the 10 patients lying on side.The deviation of monitored total dose from the total prescription dose was within -4.9％ to 6.7％ for the 10 monitored sites.The monitored dose homogeneity was less than 5.0％.Conclusions The fractionated anterior-posterior opposed parallel TBI can be finished smoothly with patients side-lying.Accurate and homogenous dose distribution can be obtained using real-time dose monitoring and compensation with solid water.