Development of a thermosensitive hydrogel system for local delivery of (188)Re colloid drugs.

A novel internal radiation therapy (IRT) mode intended for controlled local delivery of (188)Re-Tin colloid was developed by using chitosan-based thermosensitive hydrogel. Chitosan (C) and beta-glycerophosphate (beta-GP) were used to prepare the thermosensitive hydrogel (C/GP). The prepared C/GP hydrogel featured a rapid sol-gel transition within 5min after it was brought into an environment of 37 degrees C. (188)Re-Tin colloid was prepared with labeling efficiency of 93.9+/-0.6%, and could be increased to more than 98% following centrifugation. The average particle size of (188)Re-Tin colloid was 12.1+/-1.2microm, with only 7.2+/-1.5% less than 1microm. Scintigraphic study showed that (188)Re-Tin colloid contained in the C/GP hydrogel was localized (>91%) around the injection site for up to 48h post injection, verifying the intended function of the IRT design. The developed novel form of IRT in this study could be an effective treatment mode for regional radiotherapy.

Using technetium-99m methoxyisobutylisonitrile lung single-photon-emission computed tomography to predict response to chemotherapy and compare with P-glycoprotein expression in patients with untreated small cell lung cancer.

The purpose of this study was to predict chemotherapy response by technetium-99m methoxyisobutylisonitrile (Tc-99m MIBI) lung single-photon-emission computed tomography (SPECT) and compare P-glycoprotein (Pgp) expression in patients with untreated small cell lung cancer (SCLC). Before chemotherapy, 40 patients with untreated SCLC underwent Tc-99m MIBI lung SPECT. Immunohistochemical analyses were performed using multiple nonconsecutive sections of the biopsy specimens to detect Pgp expression. Chemotherapy response was evaluated in the third month after completion of treatment by clinical and radiological methods. Based on quantitative analyses, the tumor uptake ratios (TUR) of the 20 patients with good response (1.89 +/- 0.28) were significantly higher than that of the 20 patients with poor response (1.21 +/- 0.28) (p value < 0.05). Based on visual interpretation, all of the 20 patients (100%) with good response had positive Tc-99m TF lung SPECT findings and negative Pgp expression. Five of the other 20 patients (25%) with poor response had positive Tc-99m MIBI lung SPECT findings, and 12 of the other 20 patients (60%) with poor response had negative Pgp expression (p value < 0.05). Negative Tc-99m MIBI lung SPECT findings could predict poor response. Therefore, we concluded that Tc-99m MIBI lung SPECT can accurately predict the chemotherapy response, and Tc-99m MIBI lung SPECT findings can be partially compatible with Pgp expression in patients with untreated SCLC.

Lumbar bone mineral density in prostate cancer patients with bone metastases.

UNLABELLED: Because of the discrepant findings on regional bone mineral density (BMD) in stage IV patients with bone metastases due to prostate cancer, we decided to evaluate BMD of lumbar spines in 30 prostate cancer patients with lumbar spine metastases. These measurements of BMD in lumbar spines were compared with 30 stage IV prostate cancer patients without lumbar spine metastases. METHODS: Before BMD measurements, the bone scan with technetium-99m labeled diphosphonate was carried out in all of the men to evaluate lumbar spine metastases. Dual energy x-ray absorptiometry was used to measure BMD in the lumbar spines. RESULTS: There was no difference of age, height, weight, and body mass index between the two group patients. However, significantly higher BMD of the lumbar spines in the 30 patients of prostate cancers with lumbar spine metastases was found (p value <0.05). CONCLUSIONS: Our results show that patients of prostate cancers with lumbar spine metastases demonstrated by Tc-99m MDP bone scan have increased BMD in the lumbar spines, possibly because of a predominance of osteoblastic over osteolytic metastases demonstrated by Tc-99m MDP bone scan.