<strong>Background:</strong><span><span><span style="font-family:""><span style="font-family:Verdana;"> Postoperative irradiation for brain tumor in pregnan...<strong>Background:</strong><span><span><span style="font-family:""><span style="font-family:Verdana;"> Postoperative irradiation for brain tumor in pregnant women is a matter of concern. </span><b><span style="font-family:Verdana;">Aim:</span></b><span style="font-family:Verdana;"> We aimed to assess the safety of radiotherapy for brain tumors in pregnancy. We here report a successful treatment for anaplastic astrocytoma during pregnancy: surgery + postoperative irradiation. We wish to emphasize how we devised irradiation procedure to achieve both therapeutic effectiveness and safety to the fetus/infant. </span><b><span style="font-family:Verdana;">Case Presentation: </span></b><span style="font-family:Verdana;">A 34-year-old pregnant woman suffered with brain anaplastic astrocytoma. Tumor resection under craniotomy was performed with success. We decided to conduct postoperative radiotherapy at 25 weeks of gestation to reduce the risk of recurrence. We used a flattening filter-free volumetric arc therapy (FFF-VMAT) technique, which can achieve lower out-of-field dose than VMAT with a flattening filter or helical tomotherapy. We prescribed 60 Gy over 30 fractions. During actual beam delivery, surface and rectal dose to the patient (mother) were measured. The total fetal dose was estimated at 0.006 - 0.018 Gy, which is under the threshold set by the ICRP. A male healthy infant was born vaginally at the 37th week of pregnancy. The patient (mother) and the infant are healthy at the time of writing.</span><b><span style="font-family:Verdana;"> Conclusion: </span></b><span style="font-family:Verdana;">FFF-VMAT is a good choice for brain tumors during pregnancy</span></span></span></span><span style="font-family:Verdana;">.</span>展开更多
Objective The aim of the study was to compare flattening filter-free(FFF) beams and conventional flattening filter(FF) beams in volumetric modulated arc therapy(VMAT) for cervical cancer after surgery, through a retro...Objective The aim of the study was to compare flattening filter-free(FFF) beams and conventional flattening filter(FF) beams in volumetric modulated arc therapy(VMAT) for cervical cancer after surgery, through a retrospective planning study.Methods VMAT plans of FFF beams and normal FF beams were designed for a cohort of 15 patients. The prescribed dose was 45 Gy to 1.8 Gy per fraction, and at least 95% of the planning target volume received this dose. Doses were computed with a commercially available treatment planning system using a Monte Carlo(MC) algorithm. Plans were compared according to dose-volume histogram analysis in terms of planning target volume homogeneity and conformity indices(HI and CI), as well as organs at risk(OAR) dose and volume parameters. Results FFF-VMAT was similar to FF-VMAT in terms of CI, but inferior to FF-VMAT considering HI. No statistically differences were observed between FFF-VMAT and FF-VMAT in following organ at risks including pelvic bone marrow, small bowel, bladder, rectum, and normal tissue(NT)..Conclusion For patients with cervical cancer after hysterectomy, the FFF beam achieved target and OAR dose distribution similar to that of the FF beam. Reduction of beam-on time in cervical cancer is beneficial.展开更多
Objective This study aimed to analyze the dosimetric parameters of volumetric modulated arc therapy(VMAT) and dynamic multileaf collimator(DMLC) plans with lumbosacral spine(LS) and pelvic bone marrow(PBM) sparing in ...Objective This study aimed to analyze the dosimetric parameters of volumetric modulated arc therapy(VMAT) and dynamic multileaf collimator(DMLC) plans with lumbosacral spine(LS) and pelvic bone marrow(PBM) sparing in the flattening filter-free(FFF) model.Methods Thirty patients with cervical cancer were selected for analysis.For each patient,four plans with different strategies were generated:VMAT_FF,VMAT_FFF,DMLC_FF,and DMLC_FFF.Dose volumes for organs at risk,conformity index,heterogeneity index(HI),and total number of machine unit(MU) were compared by paired t-test.Result Compared with plans in the FF model,the irradiated dose to LS significantly decreased both VMAT_FFF and DMLC_FFF plans in the FFF model while the MU increased.The mean dose of LS decreased by 107.2 cGy(P<0.05) in the VMAT_FFF plan.In comparison with the VMAT plans in both models of FF and FFF,the DMLC plans reduced the dose volume of 10 Gy by 5.9%(P<0.05),and the mean dose of LS was 189.6-293.1 cGy.The PBM volume receiving 40 Gy showed a decrease of 0.5%-1.1%(P<0.05) as well.The HI increased in the VMAT plans by approximately 0.053 and 0.039.Conclusion The DMLC plans exhibited the best sparing of the PBM and LS in both FF and FFF models and increased the HI.The plans in the FFF model could limit the volume dose of LS but increase the MU.展开更多
文摘<strong>Background:</strong><span><span><span style="font-family:""><span style="font-family:Verdana;"> Postoperative irradiation for brain tumor in pregnant women is a matter of concern. </span><b><span style="font-family:Verdana;">Aim:</span></b><span style="font-family:Verdana;"> We aimed to assess the safety of radiotherapy for brain tumors in pregnancy. We here report a successful treatment for anaplastic astrocytoma during pregnancy: surgery + postoperative irradiation. We wish to emphasize how we devised irradiation procedure to achieve both therapeutic effectiveness and safety to the fetus/infant. </span><b><span style="font-family:Verdana;">Case Presentation: </span></b><span style="font-family:Verdana;">A 34-year-old pregnant woman suffered with brain anaplastic astrocytoma. Tumor resection under craniotomy was performed with success. We decided to conduct postoperative radiotherapy at 25 weeks of gestation to reduce the risk of recurrence. We used a flattening filter-free volumetric arc therapy (FFF-VMAT) technique, which can achieve lower out-of-field dose than VMAT with a flattening filter or helical tomotherapy. We prescribed 60 Gy over 30 fractions. During actual beam delivery, surface and rectal dose to the patient (mother) were measured. The total fetal dose was estimated at 0.006 - 0.018 Gy, which is under the threshold set by the ICRP. A male healthy infant was born vaginally at the 37th week of pregnancy. The patient (mother) and the infant are healthy at the time of writing.</span><b><span style="font-family:Verdana;"> Conclusion: </span></b><span style="font-family:Verdana;">FFF-VMAT is a good choice for brain tumors during pregnancy</span></span></span></span><span style="font-family:Verdana;">.</span>
基金Supported by a grant of the Military Medical Metrology Project(No.2011-JL2-005)
文摘Objective The aim of the study was to compare flattening filter-free(FFF) beams and conventional flattening filter(FF) beams in volumetric modulated arc therapy(VMAT) for cervical cancer after surgery, through a retrospective planning study.Methods VMAT plans of FFF beams and normal FF beams were designed for a cohort of 15 patients. The prescribed dose was 45 Gy to 1.8 Gy per fraction, and at least 95% of the planning target volume received this dose. Doses were computed with a commercially available treatment planning system using a Monte Carlo(MC) algorithm. Plans were compared according to dose-volume histogram analysis in terms of planning target volume homogeneity and conformity indices(HI and CI), as well as organs at risk(OAR) dose and volume parameters. Results FFF-VMAT was similar to FF-VMAT in terms of CI, but inferior to FF-VMAT considering HI. No statistically differences were observed between FFF-VMAT and FF-VMAT in following organ at risks including pelvic bone marrow, small bowel, bladder, rectum, and normal tissue(NT)..Conclusion For patients with cervical cancer after hysterectomy, the FFF beam achieved target and OAR dose distribution similar to that of the FF beam. Reduction of beam-on time in cervical cancer is beneficial.
基金General program of National Natural Science Foundation of China,31371425microRNA regulates the mechanism of mitochondrial fusion protein OPA1 involved in apoptosis induced by chemotherapy drugs Special fund of NSFC director,31240025regulation of mitochondrial injury on apoptosis induced by sorafenib
文摘Objective This study aimed to analyze the dosimetric parameters of volumetric modulated arc therapy(VMAT) and dynamic multileaf collimator(DMLC) plans with lumbosacral spine(LS) and pelvic bone marrow(PBM) sparing in the flattening filter-free(FFF) model.Methods Thirty patients with cervical cancer were selected for analysis.For each patient,four plans with different strategies were generated:VMAT_FF,VMAT_FFF,DMLC_FF,and DMLC_FFF.Dose volumes for organs at risk,conformity index,heterogeneity index(HI),and total number of machine unit(MU) were compared by paired t-test.Result Compared with plans in the FF model,the irradiated dose to LS significantly decreased both VMAT_FFF and DMLC_FFF plans in the FFF model while the MU increased.The mean dose of LS decreased by 107.2 cGy(P<0.05) in the VMAT_FFF plan.In comparison with the VMAT plans in both models of FF and FFF,the DMLC plans reduced the dose volume of 10 Gy by 5.9%(P<0.05),and the mean dose of LS was 189.6-293.1 cGy.The PBM volume receiving 40 Gy showed a decrease of 0.5%-1.1%(P<0.05) as well.The HI increased in the VMAT plans by approximately 0.053 and 0.039.Conclusion The DMLC plans exhibited the best sparing of the PBM and LS in both FF and FFF models and increased the HI.The plans in the FFF model could limit the volume dose of LS but increase the MU.
