TAT-10: Locoregional alpha-radioimmunotherapy against peritoneal metastasis of gastric cancer

Kanazawa, Japan (UroToday.com) Patients with peritoneal metastasis of gastric cancer (PMGC) have an extremely poor prognosis as no effective therapeutics have been established. Gastric cancer overexpresses HER2 about 20% of the time. Trastuzumab is a humanized anti-HER2 monoclonal antibody so we investigate At211-trastuzumab in mice models using N87 xenografts for treatment of PMGC.

TAT-10: A comparative evaluation of Ac225 and Bi213 as therapeutic radioisotopes for targeted alpha therapy

Kanazawa, Japan (UroToday.com) This is an editorial talk on the relative advantages of Ac225 and Bi213 for targeted alpha therapy. Some factors that seem like obvious advantages for one over the other might be ameliorated by various other effects. For example, the Ac225 decay chain releases four alpha particles whereas Bi213 has only one.

TAT-10: Optimization of the patient dosimetry in alphatherapy

Kanazawa, Japan (UroToday.com) Accurate dosimetry is essential in order to deliver maximum dosage to the tumor site while minimizing the dose to other organs at risk. This study develops tools for measuring the dose from Ra223. The range of alphas is to too short to image directly in humans but the decay of Ra223 also emits gamma rays as the daughter nuclei de-excite to their ground state. These gammas can be detected. SPECT imaging of the gammas was investigated for the first time.

TAT-10: Correspondence between alpha-particle emitter dosimetry and normal organ toxicity

Kanazawa, Japan (UroToday.com) Alpha particle doses are often very non-uniform within an organ so micro-dosimetry  with good resolution is necessary. This is not possible with human subjects so this study uses mice.

TAT-10: High-resolution Alpha Camera imaging as a tool for developing Targeted Alpha Therapy

Kanazawa, Japan (UroToday.com) Alpha particle dose can be highly non-uniform within an organ so microdosimetry with high resolution imaging is required for accurate dosimetry measure. An alpha camera is described to accomplish this.

TAT-10: Experimental Alpha Microdosimetry using Fluorescent Nuclear Track Detectors

Kanazawa, Japan (UroToday.com) This study uses a crystalline Al2O3:C,Mg Fluorescent Nuclear Track detector to measure the microdosimetry of alpha radiation to tissue.

TAT-10: Session IV: Nanocarriers

Kanazawa, Japan (UroToday.com) There is a substantial problem with binding the radioisotope to a molecular structure. Isotopes like Ra223 and Ac225 have decay chains that emit a total of four alphas. When the first decay occurs, the recoil of the daughter nucleus is sometimes sufficient to break the molecular bond holding the radioisotope. For the isotopes above, one of the daughter nuclei has a long enough half-life to travel through the body. This is doubly bad since not only is the alpha lost to the tumor site but the free isotope may damage healthy organs, especially the liver and kidneys.
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