Hepatocellular carcinoma(HCC) is the second leading cause of cancer-related death, as few patients can be treated with currently available curative local modalities. In patients with HCC where curative modalities are ...Hepatocellular carcinoma(HCC) is the second leading cause of cancer-related death, as few patients can be treated with currently available curative local modalities. In patients with HCC where curative modalities are not feasible, radiation therapy(RT) has emerged as an alternative or combination therapy. With the development of various technologies, RT has been increasingly used for the management of HCC. Among these advances, proton beam therapy(PBT) has several unique physical properties that give it a finite range in a distal direction, and thus no exit dose along the beam path. Therefore, PBT has dosimetric advantages compared with X-ray therapy for the treatment of HCC. Indeed, various reports in the literature have described the favorable clinical outcomes and improved safety of PBT for HCC patients compared with X-ray therapy. However, there are some technical issues regarding the use of PBT in HCC, including uncertainty of organ motion and inaccuracy during calculation of tissue density and beam range, all of which may reduce the robustness of a PBT treatment plan. In this review, we discuss the physical properties, current clinical data, technical issues, and future perspectives on PBT for the treatment of HCC.展开更多
Radiation therapy,which uses X-rays to destroy or injure cancer cells,has become one of the most important modalities to treat the primary cancer or advanced cancer.High resolution,water equivalent and passive X-ray d...Radiation therapy,which uses X-rays to destroy or injure cancer cells,has become one of the most important modalities to treat the primary cancer or advanced cancer.High resolution,water equivalent and passive X-ray dosimeters are highly desirable for developing quality assurance（QA）systems for novel cancer therapy like microbeam radiation therapy（MRT）which is currently under development.Here we present the latest developments of high spatial resolution scintillator based photonic dosimeters,and their applications to clinical external radiation beam therapies：specifically high energy linear accelerator（LINAC）photon beams and low energy synchrotron photon beams.We have developed optical fiber dosimeters with spatial resolutions ranging from 50 to 500 gm and tested them with LINAC beams and synchrotron microbeams.For LINAC beams,the fiberoptic probes were exposed to a 6 MV,10 cm by 10 cm X-ray field and,the beam profiles as well as the depth dose profiles were measured at a source-to-surface distance（SSD）of 100 cm.We have also demonstrated the possibility for temporally separating Cherenkov light from the pulsed LINAC scintillation signals.Using the 50 μm fiber probes,we have successfully resolved the microstructures of the microbeams generated by the imaging and medical beamline（IMBL）at the Australian Synchrotron and measured the peak-to-valley dose ratios（PVDRs）.In this paper,we summarize the results we have achieved so far,and discuss the possible solutions to the issues and challenges we have faced,also highlight the future work to further enhance the performances of the photonic dosimeters.展开更多
Keloids are a fibroproliferative disorder that can result from a cutaneous injury to the reticular dermis.Recurrence rates as high as 100%have been reported following surgical excision alone.Consequently,a variety of ...Keloids are a fibroproliferative disorder that can result from a cutaneous injury to the reticular dermis.Recurrence rates as high as 100%have been reported following surgical excision alone.Consequently,a variety of post-surgical techniques have been employed to prevent keloid recurrence,including the use of radiation.Although numerous studies have shown post-excisional X-rays,electron beam,lasers and brachytherapy can reduce the rate of keloid recurrence,numerous inconsistencies,including a wide range of definitions for keloid recurrence,make it difficult to compare study outcomes.The review aims to examine the various means for defining keloid recurrence in clinical trials involving the use of radiation therapy.Searches of the Cochrane Library and PubMed were performed to identify the available information for post-surgical keloid recurrence following radiation therapy.Each identified study was reviewed for patient followup and criteria used to define keloid recurrence.The search results included clinical studies with external beam radiation,brachytherapy and superficial radiation therapy.Many studies did not include a definition of keloid recurrence,or defined recurrence only as the return of scar tissue.Other studies defined keloid recurrence based on patient self-assessment questionnaires,symptoms and scar elevation and changes in Kyoto Scar Scale,Japan Scar Workshop Scale and Vancouver Scar Scale scores.The results of this review indicate keloidectomy followed by radiation therapy provide satisfactory recurrence rates;however,clinical studies evaluating these treatments do not describe treatment outcomes or use different definitions of keloid recurrence.Consequently,recurrence rates vary widely,making comparisons across studies difficult.Keloid recurrence should be clearly defined using both objective and subjective measures.展开更多
Background Nasopharyngeal carcinoma （NPC） is endemic in Southern Asia. Radiation therapy remains the mainstay of treatment strategies for NPC. Although approximately 19%-56% of patients develop a recurrent disease 5...Background Nasopharyngeal carcinoma （NPC） is endemic in Southern Asia. Radiation therapy remains the mainstay of treatment strategies for NPC. Although approximately 19%-56% of patients develop a recurrent disease 5 years after their primary treatment, recognition of post-radiation changes and early detection of relapse are important in improving the outcome of NPC. Our aim was to analyze the post-radiation changes and recurrent diseases related to NPC using computed tomography （CT） scans and to investigate their relationship. Methods CT scans of 510 pathologically proven NPC patients who have been followed up for more than 2 years after radiation were reviewed. The tumor＇s response to the radiation therapy and its relevance to recurrence were evaluated. Results For patients who were followed up for more than 2 years, their CT scans-obtained within 3 months, during the 4th to the 6th month, and beyond 7 months after radiation therapy, showed a normal nasopharyngeal cavity with a slight thickening in the wall in 93.5%, 95.0% and 84.8% of the patients respectively. The degree of tumor regression had no significant relevance to the risk of recurrence within the initial 3 months （P=0.094）. During this term, the relapse rates in the cases in which the nasopharyngeal walls were displayed as normal, slightly or moderately thickening, or with obvious residual masses on CT scans were 7.1%, 11.7%, 23.5% and 23.1% respectively. The degree of tumor regression beyond 3 months after radiation therapy had a considerable reverse relevance to the risk of recurrence （P=-0.000）. The relapse rates were 13.2%, 14.1%, 10.2% and 2.1%, respectively, in the cases with a normal and a slightly thickening nasopharyngeal wall during the 4th to the 6th month, the 7th to the 12th month, the 13th to the 24th month, and beyond 25 months after radiation. In contrast, the percents in cases with moderate or more aggressive thickening walls in the corresponding periods were 62.5%, 88.9%, 100% and 100%. Within 6 months after radiation therapy, shown by CT scans the metastatic lymph nodes disappeared, markedly decreased, slightly decreased, or enlarged in 37.4%, 51.8%, 4.7%, and 0.4%, respectively, of the patients. During 6 to 12 months after radiation therapy, the proportions were 78.5%, 19.2%, 0.6% and 1.7% correspondingly. Beyond 12 months, the proportions were 83.7%, 7.9%, 0%, and 8.4%. The regression degree of the malignant nodes after radiation therapy showed a remarkable reverse relevance to the risk of recurrence in lymph nodes （P=0.000）. In the cases with disappearing, markedly decreased, slightly decreased, or enlarged malignant nodes within six months after radiation, the relapse rates were 2.9%, 4.5%, 12.5% and 100%, respectively. Conclusions If the nasopharyngeal walls are shown to remain moderately thick on a CT scan beyond 6 months after radiotherapy, the risk of relapse will increase. The baseline images taken within 3 months after radiotherapy and regular follow-uo studies are the kev to pick up the tumor recurrences in an earlier stage.展开更多
基金Supported by a Grant from the Marine Biotechnology Program funded by the Ministry of Oceans and Fisheries,South Korea,No.20150220
文摘Hepatocellular carcinoma(HCC) is the second leading cause of cancer-related death, as few patients can be treated with currently available curative local modalities. In patients with HCC where curative modalities are not feasible, radiation therapy(RT) has emerged as an alternative or combination therapy. With the development of various technologies, RT has been increasingly used for the management of HCC. Among these advances, proton beam therapy(PBT) has several unique physical properties that give it a finite range in a distal direction, and thus no exit dose along the beam path. Therefore, PBT has dosimetric advantages compared with X-ray therapy for the treatment of HCC. Indeed, various reports in the literature have described the favorable clinical outcomes and improved safety of PBT for HCC patients compared with X-ray therapy. However, there are some technical issues regarding the use of PBT in HCC, including uncertainty of organ motion and inaccuracy during calculation of tissue density and beam range, all of which may reduce the robustness of a PBT treatment plan. In this review, we discuss the physical properties, current clinical data, technical issues, and future perspectives on PBT for the treatment of HCC.
文摘Radiation therapy,which uses X-rays to destroy or injure cancer cells,has become one of the most important modalities to treat the primary cancer or advanced cancer.High resolution,water equivalent and passive X-ray dosimeters are highly desirable for developing quality assurance（QA）systems for novel cancer therapy like microbeam radiation therapy（MRT）which is currently under development.Here we present the latest developments of high spatial resolution scintillator based photonic dosimeters,and their applications to clinical external radiation beam therapies：specifically high energy linear accelerator（LINAC）photon beams and low energy synchrotron photon beams.We have developed optical fiber dosimeters with spatial resolutions ranging from 50 to 500 gm and tested them with LINAC beams and synchrotron microbeams.For LINAC beams,the fiberoptic probes were exposed to a 6 MV,10 cm by 10 cm X-ray field and,the beam profiles as well as the depth dose profiles were measured at a source-to-surface distance（SSD）of 100 cm.We have also demonstrated the possibility for temporally separating Cherenkov light from the pulsed LINAC scintillation signals.Using the 50 μm fiber probes,we have successfully resolved the microstructures of the microbeams generated by the imaging and medical beamline（IMBL）at the Australian Synchrotron and measured the peak-to-valley dose ratios（PVDRs）.In this paper,we summarize the results we have achieved so far,and discuss the possible solutions to the issues and challenges we have faced,also highlight the future work to further enhance the performances of the photonic dosimeters.
文摘Keloids are a fibroproliferative disorder that can result from a cutaneous injury to the reticular dermis.Recurrence rates as high as 100%have been reported following surgical excision alone.Consequently,a variety of post-surgical techniques have been employed to prevent keloid recurrence,including the use of radiation.Although numerous studies have shown post-excisional X-rays,electron beam,lasers and brachytherapy can reduce the rate of keloid recurrence,numerous inconsistencies,including a wide range of definitions for keloid recurrence,make it difficult to compare study outcomes.The review aims to examine the various means for defining keloid recurrence in clinical trials involving the use of radiation therapy.Searches of the Cochrane Library and PubMed were performed to identify the available information for post-surgical keloid recurrence following radiation therapy.Each identified study was reviewed for patient followup and criteria used to define keloid recurrence.The search results included clinical studies with external beam radiation,brachytherapy and superficial radiation therapy.Many studies did not include a definition of keloid recurrence,or defined recurrence only as the return of scar tissue.Other studies defined keloid recurrence based on patient self-assessment questionnaires,symptoms and scar elevation and changes in Kyoto Scar Scale,Japan Scar Workshop Scale and Vancouver Scar Scale scores.The results of this review indicate keloidectomy followed by radiation therapy provide satisfactory recurrence rates;however,clinical studies evaluating these treatments do not describe treatment outcomes or use different definitions of keloid recurrence.Consequently,recurrence rates vary widely,making comparisons across studies difficult.Keloid recurrence should be clearly defined using both objective and subjective measures.
文摘Background Nasopharyngeal carcinoma （NPC） is endemic in Southern Asia. Radiation therapy remains the mainstay of treatment strategies for NPC. Although approximately 19%-56% of patients develop a recurrent disease 5 years after their primary treatment, recognition of post-radiation changes and early detection of relapse are important in improving the outcome of NPC. Our aim was to analyze the post-radiation changes and recurrent diseases related to NPC using computed tomography （CT） scans and to investigate their relationship. Methods CT scans of 510 pathologically proven NPC patients who have been followed up for more than 2 years after radiation were reviewed. The tumor＇s response to the radiation therapy and its relevance to recurrence were evaluated. Results For patients who were followed up for more than 2 years, their CT scans-obtained within 3 months, during the 4th to the 6th month, and beyond 7 months after radiation therapy, showed a normal nasopharyngeal cavity with a slight thickening in the wall in 93.5%, 95.0% and 84.8% of the patients respectively. The degree of tumor regression had no significant relevance to the risk of recurrence within the initial 3 months （P=0.094）. During this term, the relapse rates in the cases in which the nasopharyngeal walls were displayed as normal, slightly or moderately thickening, or with obvious residual masses on CT scans were 7.1%, 11.7%, 23.5% and 23.1% respectively. The degree of tumor regression beyond 3 months after radiation therapy had a considerable reverse relevance to the risk of recurrence （P=-0.000）. The relapse rates were 13.2%, 14.1%, 10.2% and 2.1%, respectively, in the cases with a normal and a slightly thickening nasopharyngeal wall during the 4th to the 6th month, the 7th to the 12th month, the 13th to the 24th month, and beyond 25 months after radiation. In contrast, the percents in cases with moderate or more aggressive thickening walls in the corresponding periods were 62.5%, 88.9%, 100% and 100%. Within 6 months after radiation therapy, shown by CT scans the metastatic lymph nodes disappeared, markedly decreased, slightly decreased, or enlarged in 37.4%, 51.8%, 4.7%, and 0.4%, respectively, of the patients. During 6 to 12 months after radiation therapy, the proportions were 78.5%, 19.2%, 0.6% and 1.7% correspondingly. Beyond 12 months, the proportions were 83.7%, 7.9%, 0%, and 8.4%. The regression degree of the malignant nodes after radiation therapy showed a remarkable reverse relevance to the risk of recurrence in lymph nodes （P=0.000）. In the cases with disappearing, markedly decreased, slightly decreased, or enlarged malignant nodes within six months after radiation, the relapse rates were 2.9%, 4.5%, 12.5% and 100%, respectively. Conclusions If the nasopharyngeal walls are shown to remain moderately thick on a CT scan beyond 6 months after radiotherapy, the risk of relapse will increase. The baseline images taken within 3 months after radiotherapy and regular follow-uo studies are the kev to pick up the tumor recurrences in an earlier stage.
