Intracoronary radionuclide therapy with liquid 188Re-filled balloons; radiopharmaceutical and dosimetric studies

Percutaneous transluminal coronary angioplasty associated with radioactive liquid-filled balloons has demostrated to be useful to inhibit the growth of neointimal tissue. The present study pursued optimizing the relation risk/benefit during a procedure of brachytherapy with 188Re associated to angioplasty. Since the possibility of balloon rupture exists, to increase the security during the treatment different agents such as 188Re-DTPA, 188Re-Citrate and 188Re-EC vs 188ReO4 were evaluated. Dosimetric studies using Mirdose 3, after iv injection to Wistar rats, evaluation of a number of safety requirements in order to estimate radiation dose delivered to operating personnel and absorbed doses estimated by Monte Carlo method (PENELOPE). It is a safe procedure, both for the patient and the working staff; in case of ballon rupture the use of the above mentioned radiopharmaceuticals increases its security. 188Re beta emitor achieves a local dosis, diminishing the dose in healthy tissue.

Preparation of (188) Re-labeled paper for treating skin cancer.

For homogeneous delivery of beta radiation to skin cancer, we developed a simple method for preparing (188) Re-labeled nitrocellulose paper. The homogeneity and stability of the labeled paper were investigated. Absorbed dose estimates were calculated using the Monte-Carlo method. A 74-MBq (188) Re-labeled paper with 1-cm diameter delivered 147.2 Gy up to 1-mm depth after 2-h irradiation. Animal experiments on tumor-bearing mice showed that 50 Gy is an adequate dose for treating skin cancer. Tumors disappeared 7 days after irradiation in all the groups irradiated by 50 or 100 Gy. The (188) Re-labeled paper provided a convenient, economical, effective, and non-invasive method of treating skin cancer.