Proton therapy for hepatocellular carcinoma:Current knowledges and future perspectives

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.

Recent advances in photonic dosimeters for medical radiation therapy

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.

浅层X线照射联合消疣汤治疗尖锐湿疣98例

目的为了能更好治疗尖锐湿疣,本次研究采用X线照射联合消疣汤的中西医结合治疗方法,观察治疗效果以及后继的复发情况。方法选择尖锐湿疣,共98例参与研究,将患者分成研究组、对照组,每组各半。对照组只采用西医的X线照射(SRT-100浅层X线照射)治疗。研究组则采用X线照射+消疣汤的中西医结合治疗方法。结果对照组、研究组治愈率分别为75.51%(37/49)、93.87%(46/49);对照组、研究组3个月的复发率分别为44.9%(22/49)、12.24%(6/49)。2组数据对比P<0.05,差异具有统计学意义。结论采用X线照射联合消疣汤的中西医结合治疗方法有效率更高,复发率更低,具有安全、可靠的优点,可在临床上推广使用。

CO_2激光联合浅层X线照射治疗肛周尖锐湿疣的临床疗效观察

目的:观察应用CO_2激光联合浅层X线照射治疗肛周尖锐湿疣的疗效及复发率。方法:肛周尖锐湿疣患者132例,随机分为治疗组和对照组两组。对照组用CO_2激光治疗,常规皮肤消毒,局麻后每个皮损连续点灼,范围超过疣体基底部,术毕可外涂抗炎药膏,保护创面。治疗组用CO_2激光联合SRT-100浅层X线照射治疗,CO_2激光清除疣体后即刻照射1次,3d,7d,15d各照射1次,4次为1疗程,结束后随访3个月。结果:对照组治愈率52.24%,复发率为47.76%;治疗组治愈率86.16%,复发率为13.84%。治疗组与对照组的治愈率及3个月后的复发率比较,差异均有统计学意义(P<0.05)。结论:CO_2激光联合SRT-100浅层X线照射治疗能有效治疗肛周尖锐湿疣,具有安全,治愈率高,复发率低,患者依从性好。

Post-radiation CT changes and recurrent nasopharyngeal carcinoma

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.

深部埋置环形褥式缝合联合浅层X射线放射治疗胸背部瘢痕疙瘩的疗效分析

目的探讨深部埋置环形褥式缝合联合浅层X射线放射治疗胸背部瘢痕疙瘩的临床疗效。方法选取102例胸背部瘢痕疙瘩患者,采用深部埋置环形褥式缝合技术进行治疗,术后进行病理HE染色分析,于术后24 h内行第1次浅层X射线放射治疗,每隔5 d 1次,共4次。于术后1个月、3个月、6个月及1年观察患者的临床疗效,记录患者术后并发症发生率及满意率。结果瘢痕组织HE染色可见表皮萎缩变薄,真皮中上部成纤维细胞及胶原增生,增生的毛细血管周围可见稀疏的炎细胞浸润。术后1个月、3个月、6个月及1年,患者治疗有效率分别为100%、99.02%、96.08%及89.22%;术后总体并发症发生率为16.67%,总体满意率为97.06%。结论胸背部瘢痕疙瘩手术切除后采取深部埋置环形褥式缝合技术联合浅层X射线放射治疗,患者可取得较好的临床疗效,且具有复发率低、无严重并发症等优点。