Objective:This study was to compare 5 field conformal technique to the intensity modulated radiotherapy (IMRT) 8 fields technique in boosting locally advanced cancer cervix cases after external beam radiotherapy with ...Objective:This study was to compare 5 field conformal technique to the intensity modulated radiotherapy (IMRT) 8 fields technique in boosting locally advanced cancer cervix cases after external beam radiotherapy with respect to target volume coverage and dose to normal tissues. Methods:We conducted a single institutional comparative dosimetric analysis of 10 patients with cancer cervix who was presented to radiotherapy department in National Cancer Institute, Cairo in period between June 2012 to September 2012 and received a CRT boost in the place of planned brachytherapy after large field pelvic radiotherapy (PRT) with concurrent chemotherapy were retrospectively identified. All tumors were situated in the low central pelvis. Two plans were done for every patient; one using the 8 fields IMRT and the second one using 5 fields' 3DCRT the two techniques were then compared using dose volume histogram (DVH) analysis for the PTV, bladder, rectum and both femoral heads. Results:Comparing different DVHs, it was found that the planning target volume (PTV) was adequately covered in both plans while it was demonstrates that the 8 fields IMRT technique carried less doses reaching OARs (rectum, bladder, both femoral heads). Conclusion:From the present study, it is concluded that IMRT technique spared more efficiently OARs than CRT technique but both techniques covered the PTV adequately so whenever possible IMRT technique should be used.展开更多
Purpose: To test the use of Intensity Modulated Radiotherapy (IMRT) to spare the bone marrow (BM) in patients treated with cancer cervix through using the bone marrow an organ at risk. Patients and methods: Thirteen p...Purpose: To test the use of Intensity Modulated Radiotherapy (IMRT) to spare the bone marrow (BM) in patients treated with cancer cervix through using the bone marrow an organ at risk. Patients and methods: Thirteen patients with stage (IB2-IIIB) intact cervix cancer were included;C-T simulation was done with contrast and full bladder with slice thickness 2.5 mm. Clinical Target Volume (CTV) included the cervix, uterus, upper half of the vagina, parametrium and regional lymph nodes. The CTV was expanded by 1 cm to form the Planning Target Volume (PTV). The organ at risk (OAR) included the bladder and rectum, the external contour of the pelvic bones to define the Pelvic Bone Marrow (PBM). Four plans were done for every patient with anteroposterior-posteroanterior (AP/PA), three dimensional conformal radiotherapy (3DCRT), IMRT, bone marrow-sparing intensity-modulated pelvic radiotherapy (BMS-IMRT). Results: BMS-IMRT reduced the V20, V30, V40 and V45 of the BM in comparison to 3DCRT and IMRT plans. Reduction in V20 with BMS-IMRT plan compared to 3DCRT (p 0.03). The PBM volume receiving 5, 10 and 20 Gy was lower AP/PA than BMS-IMRT (p < 0.01, p 0.001 and p 0.04 respectively). The volumes of the rectum and bladder receiving dose of 40 and 45 Gy were lower in BMS-IMRT plan compared to AP/PA and 3DCRT plans with p = 0.01 for both of them. PTV cover was better in the BMS-IMRT and IMRT plans. Conclusion: BMS-IMRT decreased the irradiated BM volume compared to other techniques. Thus using BMS-IMRT is recommended to decrease hematological toxicity and avoid treatment interruption.展开更多
文摘Objective:This study was to compare 5 field conformal technique to the intensity modulated radiotherapy (IMRT) 8 fields technique in boosting locally advanced cancer cervix cases after external beam radiotherapy with respect to target volume coverage and dose to normal tissues. Methods:We conducted a single institutional comparative dosimetric analysis of 10 patients with cancer cervix who was presented to radiotherapy department in National Cancer Institute, Cairo in period between June 2012 to September 2012 and received a CRT boost in the place of planned brachytherapy after large field pelvic radiotherapy (PRT) with concurrent chemotherapy were retrospectively identified. All tumors were situated in the low central pelvis. Two plans were done for every patient; one using the 8 fields IMRT and the second one using 5 fields' 3DCRT the two techniques were then compared using dose volume histogram (DVH) analysis for the PTV, bladder, rectum and both femoral heads. Results:Comparing different DVHs, it was found that the planning target volume (PTV) was adequately covered in both plans while it was demonstrates that the 8 fields IMRT technique carried less doses reaching OARs (rectum, bladder, both femoral heads). Conclusion:From the present study, it is concluded that IMRT technique spared more efficiently OARs than CRT technique but both techniques covered the PTV adequately so whenever possible IMRT technique should be used.
文摘Purpose: To test the use of Intensity Modulated Radiotherapy (IMRT) to spare the bone marrow (BM) in patients treated with cancer cervix through using the bone marrow an organ at risk. Patients and methods: Thirteen patients with stage (IB2-IIIB) intact cervix cancer were included;C-T simulation was done with contrast and full bladder with slice thickness 2.5 mm. Clinical Target Volume (CTV) included the cervix, uterus, upper half of the vagina, parametrium and regional lymph nodes. The CTV was expanded by 1 cm to form the Planning Target Volume (PTV). The organ at risk (OAR) included the bladder and rectum, the external contour of the pelvic bones to define the Pelvic Bone Marrow (PBM). Four plans were done for every patient with anteroposterior-posteroanterior (AP/PA), three dimensional conformal radiotherapy (3DCRT), IMRT, bone marrow-sparing intensity-modulated pelvic radiotherapy (BMS-IMRT). Results: BMS-IMRT reduced the V20, V30, V40 and V45 of the BM in comparison to 3DCRT and IMRT plans. Reduction in V20 with BMS-IMRT plan compared to 3DCRT (p 0.03). The PBM volume receiving 5, 10 and 20 Gy was lower AP/PA than BMS-IMRT (p < 0.01, p 0.001 and p 0.04 respectively). The volumes of the rectum and bladder receiving dose of 40 and 45 Gy were lower in BMS-IMRT plan compared to AP/PA and 3DCRT plans with p = 0.01 for both of them. PTV cover was better in the BMS-IMRT and IMRT plans. Conclusion: BMS-IMRT decreased the irradiated BM volume compared to other techniques. Thus using BMS-IMRT is recommended to decrease hematological toxicity and avoid treatment interruption.
