Purpose: To study the effect of escalating radiation dose;in intermediate and high risk prostate cancer patients;via online image-guidance on acute toxicities. Patients and Methods: thirty-eight prostate cancer patien...Purpose: To study the effect of escalating radiation dose;in intermediate and high risk prostate cancer patients;via online image-guidance on acute toxicities. Patients and Methods: thirty-eight prostate cancer patients were treated by using simultaneous integrated boost-intensity modulated radiation therapy (SIB-IMRT) with online image guided correction via kilo voltage cone beam computed tomography (KV-CBCT)/electronic portal imaging device (EPID) of trans-rectal ultrasound (TRUS)-inserted intraprostatic gold fiduciary markers. High-risk patients received a median dose of 80.5 Gy to prostate and 56 Gy to pelvic nodes in 35 fractions over 7 weeks. Intermediate-risk patients received a similar prostate dose over the same overall treatment time. Acute toxicity (bladder, rectal and bowel symptoms) was reported once weekly during the radiation course and up to 3 months from the end of the radiation course. Results: The image guided (IG)-IMRT allows escalating the radiation dose delivered to the prostate through minimizing the margin of setup error to less than 0.5 cm with subsequent sparing of nearby organs at risk. Out of thirty-eight patients, no patient developed >grade 1 acute rectal toxicity, 7.9% of patients experienced grade 3 urinary toxicity and there was no reported small intestinal toxicity. Conclusion: Escalating the radiation dose more than 80 Gy in intermediate and high risk prostate cancer patients was safe and not associated with grade 3 - 4 RTOG toxicity when guided by online verification of intra-prostatic fiducial markers.展开更多
Image-guided radiotherapy(IGRT) provides precise positioning for the tumor target, but it may bring extra irradiation dose in the target positioning with a cone beam CT(CBCT) which has been increasingly used in IGRT. ...Image-guided radiotherapy(IGRT) provides precise positioning for the tumor target, but it may bring extra irradiation dose in the target positioning with a cone beam CT(CBCT) which has been increasingly used in IGRT. In this work, we focused on biological effects of the low-dose irradiation in IGRT, which have not been considered so far. Primary human fibroblasts cells from the lung and MRC-5 were irradiated by a CBCT. DNA doublestrand breaks(c-H2 AX foci) and micronucleus frequency of the irradiated samples were analyzed. Compared to the control, the c-H2 AX foci yields of the samples irradiated to 16 m Gy increased significantly, and the micronuclei rate of the samples irradiated for 3 days increased notably. The dose by imaging guidance device can be genotoxic to normal tissue cells, suggesting a potential risk of a secondary cancer. The effects, if confirmed by clinical studies,should be considered prudentially in designing IGRT treatment plans for the radiosensitive population, especially for children.展开更多
We proposed the use of a hybrid deformable image registration approach that combines compact-support radial basis functions (CSRBF) spline registration with intensity-based image registration. The proposed method firs...We proposed the use of a hybrid deformable image registration approach that combines compact-support radial basis functions (CSRBF) spline registration with intensity-based image registration. The proposed method first uses the pre-viously developed image intensity-based method to achieve voxel-by-voxel correspondences over the entire image re-gion. Next, for those areas of inaccurate registration, a sparse set of landmark correspondences was defined for local deformable image registration using a multi-step CSRBF approach. This hybrid registration takes advantage of both intensity-based method for automatic processing of entire images and the CSRBF spline method for fine adjustment over specific regions. The goal of using this hybrid registration is to locally control the quality of registration results in specific regions of interest with minimal human intervention. The major applications of this approach in radiation ther-apy are for the corrections of registration failures caused by various imaging artifacts resulting in, low image contrast, and non-correspondence situations where an object may not be imaged in both target and source images. Both synthetic and real patient data have been used to evaluate this hybrid method. We used contours mapping to validate the accuracy of this method on real patient image. Our studies demonstrated that this hybrid method could improve overall registra-tion accuracy with moderate overhead. In addition, we have also shown that the multi-step CSRBF registration proved to be more effective in handling large deformations while maintaining the smoothness of the transformation than origi-nal CSRBF.展开更多
文摘Purpose: To study the effect of escalating radiation dose;in intermediate and high risk prostate cancer patients;via online image-guidance on acute toxicities. Patients and Methods: thirty-eight prostate cancer patients were treated by using simultaneous integrated boost-intensity modulated radiation therapy (SIB-IMRT) with online image guided correction via kilo voltage cone beam computed tomography (KV-CBCT)/electronic portal imaging device (EPID) of trans-rectal ultrasound (TRUS)-inserted intraprostatic gold fiduciary markers. High-risk patients received a median dose of 80.5 Gy to prostate and 56 Gy to pelvic nodes in 35 fractions over 7 weeks. Intermediate-risk patients received a similar prostate dose over the same overall treatment time. Acute toxicity (bladder, rectal and bowel symptoms) was reported once weekly during the radiation course and up to 3 months from the end of the radiation course. Results: The image guided (IG)-IMRT allows escalating the radiation dose delivered to the prostate through minimizing the margin of setup error to less than 0.5 cm with subsequent sparing of nearby organs at risk. Out of thirty-eight patients, no patient developed >grade 1 acute rectal toxicity, 7.9% of patients experienced grade 3 urinary toxicity and there was no reported small intestinal toxicity. Conclusion: Escalating the radiation dose more than 80 Gy in intermediate and high risk prostate cancer patients was safe and not associated with grade 3 - 4 RTOG toxicity when guided by online verification of intra-prostatic fiducial markers.
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA03040000)the National Natural Science Foundation under Grant No.30900386+1 种基金the Anhui Provincial Natural Science Foundation under Grant Nos.090413095 and 11040606Q55the National Natural Science Foundation of Department of Education of Anhui Province under Grant No KJ2010B380
文摘Image-guided radiotherapy(IGRT) provides precise positioning for the tumor target, but it may bring extra irradiation dose in the target positioning with a cone beam CT(CBCT) which has been increasingly used in IGRT. In this work, we focused on biological effects of the low-dose irradiation in IGRT, which have not been considered so far. Primary human fibroblasts cells from the lung and MRC-5 were irradiated by a CBCT. DNA doublestrand breaks(c-H2 AX foci) and micronucleus frequency of the irradiated samples were analyzed. Compared to the control, the c-H2 AX foci yields of the samples irradiated to 16 m Gy increased significantly, and the micronuclei rate of the samples irradiated for 3 days increased notably. The dose by imaging guidance device can be genotoxic to normal tissue cells, suggesting a potential risk of a secondary cancer. The effects, if confirmed by clinical studies,should be considered prudentially in designing IGRT treatment plans for the radiosensitive population, especially for children.
文摘We proposed the use of a hybrid deformable image registration approach that combines compact-support radial basis functions (CSRBF) spline registration with intensity-based image registration. The proposed method first uses the pre-viously developed image intensity-based method to achieve voxel-by-voxel correspondences over the entire image re-gion. Next, for those areas of inaccurate registration, a sparse set of landmark correspondences was defined for local deformable image registration using a multi-step CSRBF approach. This hybrid registration takes advantage of both intensity-based method for automatic processing of entire images and the CSRBF spline method for fine adjustment over specific regions. The goal of using this hybrid registration is to locally control the quality of registration results in specific regions of interest with minimal human intervention. The major applications of this approach in radiation ther-apy are for the corrections of registration failures caused by various imaging artifacts resulting in, low image contrast, and non-correspondence situations where an object may not be imaged in both target and source images. Both synthetic and real patient data have been used to evaluate this hybrid method. We used contours mapping to validate the accuracy of this method on real patient image. Our studies demonstrated that this hybrid method could improve overall registra-tion accuracy with moderate overhead. In addition, we have also shown that the multi-step CSRBF registration proved to be more effective in handling large deformations while maintaining the smoothness of the transformation than origi-nal CSRBF.
