Abstract
Purpose: Previous studies using FLASH radiotherapy (RT) in mice showed a marked increase of the differential effect between normal tissue and tumors. To stimulate clinical transfer, we evaluated whether this effect could also occur in higher mammals. Experimental Design: Pig skin was used to investigate a potential difference in toxicity between irradiation delivered at an ultrahigh dose rate called "FLASH-RT" and irradiation delivered at a conventional dose rate called "Conv-RT." A clinical, phase I, single-dose escalation trial (25–41 Gy) was performed in 6 cat patients with locally advanced T2/T3N0M0 squamous cell carcinoma of the nasal planum to determine the maximal tolerated dose and progression-free survival (PFS) of single-dose FLASH-RT. Results: Using, respectively, depilation and fibronecrosis as acute and late endpoints, a protective effect of FLASH-RT was observed (20% dose-equivalent difference vs. Conv-RT). Three cats experienced no acute toxicity, whereas 3 exhibited moderate/mild transient mucositis, and all cats had depilation. With a median follow-up of 13.5 months, the PFS at 16 months was 84%. Conclusions: Our results confirmed the potential advantage of FLASH-RT and provide a strong rationale for further evaluating FLASH-RT in human patients.
Original language | English |
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Pages (from-to) | 35-42 |
Number of pages | 8 |
Journal | Clinical Cancer Research |
Volume | 25 |
Issue number | 1 |
DOIs | |
Publication status | Published - 2019 Jan 1 |
Externally published | Yes |
Bibliographical note
Publisher Copyright:© 2019 American Association for Cancer Research.
Subject classification (UKÄ)
- Cancer and Oncology
- Radiology, Nuclear Medicine and Medical Imaging