252锎中子后装加外照射治疗子宫颈癌的疗效观察

目的观察252锎（252Cf）中子腔内后装加外照射治疗宫颈癌的近期疗效以及并发症的发生情况。方法选择36例未接受过任何治疗的临床分期为Ⅱ、Ⅲ期的宫颈癌患者,其中Ⅱa期6例,Ⅱb期18例,Ⅲa期8例,Ⅲb期4例。252Cf中子腔内后装治疗,宫旁A点剂量为6—10Gy／次,1次／周,共4～6次,使宫旁A点累积剂量达30～42Gy。全盆腔外照射和中子后装同期进行,后装治疗当天不进行外照射,前后对穿野,1．8—2．0Gy／次,4次／周,外照射20—34Gy后,盆腔野中间挡铅4cm,使总剂量达到45～50GY,总疗程5—7周。结果36例患者均随访2年,2年局部控制率为97％,2年生存率为92％,其中Ⅱa期100％,Ⅱb期94％,Ⅲa期88％,Ⅲb期75％。放射性膀胱炎发生率6％,放射性直肠炎发生率8％。结论252Cf中子腔内后装加外照射治疗宫颈癌,患者能较好耐受,同常规γ射线后装治疗比较,临床Ⅱ、Ⅲ期患者近期疗效好,并发症发生率低。     

Stability of biodegradable radioactive rhenium (Re-186 and Re-188) microspheres after neutron-activation

Our objective was to determine if microspheres made from the biodegradable polymer poly(lactic acid) that contained rhenium could withstand the conditions of direct neutron activation necessary to produce therapeutic amounts of radioactive rhenium. The radiation damage of the polymer produced by γ-doses of up to 1.05 MGy from Re-186 and Re-188 was examined by scanning electron microscopy and size exclusion chromatography. At a thermal neutron flux of 1.5×10¹³ n/cm²/s the microspheres melted after 3 h in the nuclear reactor, but suffered little damage after 1 h of radiation and released less than 5% of the radioactivity during incubation in buffer at 37°C. The radioactive microspheres produced in this manner have a specific activity too low for radioembolization for treatment of liver tumors, but could be injected directly into tumors or applied topically to the wound bed of partially resected tumors.     

Neutron brachytherapy in the modern era: Indications and evidence

Hadrontherapy is a form of radiation therapy (RT) that relies on heavy particles, such as proton, heavy ions, or neutrons, to enhance anti-tumoral efficacy based on their specific dosimetric and radio-biological properties. Neutrons are characterized by specific radiobiological properties that might deserve greater consideration, including the high linear energy transfer and the low oxygen enhancement ratio. Neutron brachytherapy, relying on interstitial or intracavitary neutron sources, has been developed since the 1950s using Californium-252 (252Cf) as a mixed emitter of fission fast neutrons and γ-photos. However, the place of NBT in the era of modern radiation therapy is yet to be precisely defined. In this systematic review, we aim to provide an up-to-date analysis of current experience and clinical evidence of NBT in the XXI ^th century, by answering the following clinical questions: How is NBT currently delivered? What are the current efficacy data and tolerance profiles of NBT?