Author: Lili Chen, Andy T. Clark, Dusica Cvetkovic, Chang Ming Charlie Ma, Dae-Myoung Yang 👨🔬
Affiliation: Fox Chase Cancer Center 🌍
Purpose: Radiodynamic therapy (RDT) shows promise as a strategy to inhibit the metastasis of premetastatic small cell lung cancer (SCLC). This study evaluates the therapeutic effect of RDT in inhibiting metastases in vivo.
Methods: C57BL/6 mice were inoculated via the lateral tail vein with 106 KP1 SCLC cells. Mice were randomized into five groups: Control (0Gy, n=9), low-dose RT (0.1Gy, n=8), low-dose RDT (0.1Gy, n=8), high-dose RT (2Gy, n=11), and high-dose RDT (2Gy, n=10). For RDT groups, 5-aminolevulinic acid (5-ALA) was administered retro-orbitally four hours before irradiation. Radiation was delivered in a single fraction to the whole body one day post-inoculation using an open beam of 18MV photon beam with 3 cm buildup. Tumor progression was assessed using preclinical 3T MRI, and survival was monitored for up to 10 weeks.
Results: Low-dose and high-dose RDT groups showed trends towards inhibition of metastases compared to control and RT groups, as evidenced by MRI. By week 4, tumor burden was high in control and RT groups, whereas RDT groups exhibited minimal or no signs of tumor burden by week 6. Survival analysis indicated that RDT groups had longer survival, with a noticeable separation from control and RT groups. These findings suggest the potential of RDT to inhibit metastases in premetastatic SCLC.
Conclusion: RDT demonstrates a promising approach for inhibiting metastases and improving survival in premetastatic SCLC. These findings highlight the potential of RDT to offer therapeutic benefits over conventional RT, supporting its continued investigation as a novel treatment strategy for preventing metastases in aggressive cancers.