The effect of Nd:YAG laser-induced hyperthermia on local tumor recurrence in experimental rat mammary tumors.

The influence of Nd:YAG laser hyperthermia (45 degrees C for 20 min) on local tumor recurrence followed by CO 2 laser or scalpel excision was studied on 150 F344 female rats that were implanted with R3230AC mammary tumor in the mammary ridge. The development of local tumor recurrence was observed for 39 days postoperatively. All groups undergoing CO 2 laser excision showed a significant reduction in local tumor recurrence (p less than 0.05) compared with the scalpel technique. Animals that underwent CO 2 laser excision and wound sterilization 48 h following laser hyperthermia demonstrated the lowest recurrence when compared with scalpel excision (p less than 0.01). These results indicate that the local thermal effect achieved by laser hyperthermia or laser sterilization plays an important role in the reduction of local tumor recurrence and augments complete local tumor resection.