Fractionated FLASH radiation in xenografted lung tumors induced FLASH effect at a split dose of 2 Gy.

Purpose: To explore the minimum split dose of FLASH radiotherapy (FLASH).

Material And Methods: Lungs of nude mice were used to verify the capacity of normal tissue sparing of FLASH, while tumor-bearing nude mice were used to evaluate the curative power. Xenografted tumor models were established in Balb/c-nu mice using A549 cells at a concentration of With the same total dose (20 Gy), the dose rate of FLASH was 200 Gy/s when conventional radiotherapy(CONV) was 0.

[Treatment of nasal malignant tumor with electron beam irradiation after repair of nasolabial flap].

Objective: To explore the appropriate reconstructive methods and curative effect after nasal skin malignant tumor excision.

Method: Nasolabial flap was selected to cover the nasal defects in 15 cases which nasal tumors were removed. The secondary defect of donor site was directly sutured.