[en] We have developed a flexible radioactive polyurethane patch incorporating β-emitting radionuclide (166Ho) to treat malignant skin lesions. We covered the tumor surface (n=133) with the radioactive patch for 33.58 ± 5.33 minutes. Radiation dose delivered was 35 Gy for Bowen's disease (n=78), Kaposi sarcoma (n=25), actinic keratosis (n=5), and 50 Gy for BCC (n=17) and squamous carcinoma (n=8). Complete response was observed in 91.7% after the first therapeutic trial, 96.2% after 2nd and 97.7% after 4th trial with excellent cosmetic outcome for 31.15±13.88 months of follow-up. Radioactive patch therapy is effective for superficial skin cancers that are impractical for surgery

[en] To evaluate the usefulness of a beta-emitting radionuclide (holmium-166-chitosan complex) as a sclerosing agent for the treatment of renal cysts. Using 10-30 mCi of holmium-166-chitosan complex, 20 renal cysts in 17 patients (14 male and 3 female patients, ranging in age from 47 to 82 years) were treated by percutaneous sclerotherapy under ultrasonographic guidance. The volume of the cysts before and after the sclerotherapy and the percentage change in volume were calculated in order to evaluate the response to therapy, which was classified as either complete regression (invisible), nearly complete regression (< 15 volume% of initial volume), partial regression (15-50 volume%) or no regression (> 50 volume%). The follow-up period ranged from 6 to 36 months (mean 28 months). Eighteen cysts (90%) regressed completely (n=11, 55%) or near-completely (n=7, 35%). Partial regression was obtained in one patient (5%) and there was no regression in one patient (5%). No significant complications were encountered. The holmium-166-chitosan complex seems to be useful as a new painless sclerosing agent for the treatment of renal cysts with no significant complications

[en] Antiangiogenic monoclonal antibodies in combination with therapeutic radionuclides are potential targeted therapy agents in cancer. In this study, bevacizumab was successively labeled with [¹⁶⁶Ho]HoCl₃ after conjugation with DOTA-NHS-ester with a radiochemical purity of higher than 95% (RTLC). The conjugates were purified by molecular filtration, the average number of DOTA conjugated per mAb was calculated and total concentration was determined by spectrophotometric method and the average chelate to antibody ratio (c/a) for the conjugate used in this study was 5.8:1 and protein integrity experiments (SDS-PAGE). The biodistribution studies in wild-type rats demonstrate a similar pattern to the other radiolabeled anti-vascular endothelial growth factor A (VEGF-A) immunoconjugates. ¹⁶⁶Ho-DOTA-bevacizumab is a potential compound for therapy/imaging of VEGF-A expression in oncology. (author)

[en] Short communication

[en] Using an anti-Compton spectrometer, the gamma ray spectrum of ^166mHo was remeasured with the aim to reveal new Low-intensity gamma transitions since ^166mHo is a recommended calibration standard for Ge(Li) or HPGe detectors. Altogether, 61 gamma transitions were assigned to the ^166mHo decay. All of them were established in the decay scheme. (author). 2 figs., 2 tabs., 16 refs

[en] Neointimal hyperplasia following ballon angioplasty procedure for an occlusive coronary artery (CA) disease is one of the important contributing factors of restenosis. The purpose of our study was to investigate the effectiveness of intravascular Ho-166 (T_1/2 : 1.15d, E_β : 1.84MeV, R : 8 mm) application in inhibition of neointimal formation after the ballon injury to porcine coronary arteries. Nineteen domestic pigs weighing 25∼35 kg underwent balloon injury (balloon/artery ratio : 1.3 ∼ 1.4) to the proximal portions of LAD and LCX. One injured site was randomly irradiated by keeping liquid form of Ho-166 within the balloon for sufficient time to deliver beta radiation (0, 9, 18 Gy to 1mm depth). Four weeks later, pigs were sacrified and hearts were perfusion-fixed. Serial 2 to 3 μm slices of CAs were processed and embeded in paraffin. The maximal initimal thickness (MIT), luminal area, intimal area and vessel areas were measured. MIT was 0.48±0.13 mm in control ( 0 Gy, 32 sites) 0.42 ±0.05 in 9 Gy (20 sites) and 0.14 ±0.08 in 18 Gy (23 sites) group (P<0.05 vs control). Intimal area and smooth muscle proliferation was significantly reduced in 18 Gy group. Intra-balloon delivery of liquid form Ho-166 is feasible and effective in inhibiting neointimal hyperplasia caused by PTCA in swine model. This method may be able to reduce tha rate of restenosis following balloon angioplasty

No abstract available

[en] Hepatocellular carcinoma (HCC) is one of the major malignancies in Asian countries and it is highly invasive and shows poor response to ordinary chemotherapy or external radiation therapy and because of poor response, Ho-166-chitosan complex was developed as a new compound for internal radiotherapy of HCC and were performed in HCC patients

[en] Skin cancer is the most common malignant tumors in human. Therapeutic modalities of the skin cancers are local destruction, radiotherapy and surgery. External radiation therapy leads to good results, however, overall 5-6 weeks of treatment period is needed to deliver optimal radiation dose to tumors. In this study, β-emitting radionuclide, Ho-166, impregnated in a specially designed patch was utilized to superficial skin cancers and Bowen's disease for local irradiation. Methods; Animal study was employed in 10 mice with chemically induced skin tumors. Five- mm size patches containing 22.2 -72.15 MBq(0.6 - 1.95 mCi) of Ho-166 were applied to the tumor surface for 1 -2 hr. In clinical trial, patients with squamous carcinoma(n=3), basal cell carcinoma(n=1), and Bowen's disease(n=1) were treated with patches containing 273.8 - 999 MBq (7.4 - 27 mCi) of Ho-166 for 30 minutes to 1 hour. Pathologic examination was performed 4 - 7 weeks after the treatment in animal model. Skin biopsy was performed 8 weeks post-treatment in four patients. Results; Tumor destruction was seen 1 week post the treatment, however, radiation dermatitis or ulceration developed at the site of radionuclide application. Those reactions healed gradually with fibrosis or epithelialization, which was confirmed pathologically. No significant adverse reaction to radiation except subcutaneous fibrosis was found. Conclusion; Superficial skin tumors could be successfully treated by topical application of β-emitting radionuclides. (author)

No abstract available