Abstract:

Objective  To investigate lymphoscintigraphy and enrichment of 99mTc-FL in regional lymph nodes by SPECT to provide a basis for the regional lymph system targeted chemotherapy of malignant tumors. Methods  6 rabbitswere hypodermically injected with 0.5mCi of 99m-]Tc-FL in the firstmedial web on the dorsum of lower extremities. Lymphatic flow imaging was dynamically traced by SPECT in 30 or 60 minutes after injection. The diffusion and gathering of the radioisotope in the regional lymphatic vessels and lymph nodes were monitored by SPECT at different intervals within 8h. The scintigraphy counting ratios(%) in injected sites or in the regional lymph system including lymph nodes in the popliteal fossa, in pelvic cavity, in the post-peritoneum and the cisterna chyli were measured respectively at 1h, 3h and 6h post-injection. Results  The tracing of dynamic lymph flow in 30 or 60 minutes and imaging at different intervals in 8h post-injection by SPECT showed that 99mTc-FL could slowly flow into the regional lymph system from injected sitesand highly accumulated in their lymph nodes, but the radioactivity uptake ratios of the other organs were low. 1h, 2h and 3h post-injection, and the scintigraphy counting ratios of the three groups, in injected sites or the regional lymph system hadstatistical differences(P＜0.05). The scintigraphy counting ratios in injected sites were gradually decreasing, but rising in regional lymph nodes. The comparisons between the scintigraphy counting ratios in the regional lymph nodes and in the other organs (except injected sites) per group were significantly different(P＜0.05).　The scintigraphy counting ratios in regional lymph system were sharplyhighly than in other organs. Conclusions  99m-Tc-FL can flow into regional lymphatic chains rather than directly enter blood circulation. 99m-]Tc-FL can be highlyaccumulated in the regional lymph nodes. Therefore, the regional lymph system targeted chemotherapy for malignant tumors is clinically feasible.

Key words: Neoplasms；  Liposomes；  Lymph nodes；  Radionuclide imaging