Biological effectiveness on live cells of laser driven protons at dose rates exceeding 109 Gy/s

Abstract

The ultrashort duration of laser-driven multi-MeV ion bursts offers the possibility of radiobiological studies at extremely high dose rates. Employing the TARANIS Terawatt laser at Queen’s University, the effect of proton irradiation at MeV-range energies on live cells has been investigated at dose rates exceeding 109 Gy/s as a single exposure. A clonogenic assay showed consistent lethal effects on V-79 live cells, which, even at these dose rates, appear to be in line with previously published results employing conventional sources. A Relative Biological Effectiveness (RBE) of 1.4±0.2 at 10% survival is estimated from a comparison with a 225kKVp X-ray source

Dose-controlled irradiation of cancer cells with laser-accelerated proton pulses

“…Both radiobiological results are in good agreement with a complementary experiment performed at the Munich Tandem Van-de-Graaf accelerator [37,38] and a recent study of the RBE of intense single pulses of LDPR, where the dose applied to the cells was varying across the probe and analyzed retrospectively for individual irradiated areas [26]. Making use of different pulse modes of the Tandem accelerator, the first study focused on the dependence of the RBE on the peak dose rate by comparing the effect of short-pulses (few nanoseconds) and continuous beams of 20 MeV protons, while the latter directly made use of the intrinsically high peak dose rates of LDPR of up to few Gy per pulse.…”

“…This work is building on previous work from our group [22] and the radiobiological results are consistent with first experiments performed by Yogo et al [24,25] and a recent single-pulse study of the RBE by Doria et al [26] with retrospective dose evaluation.…”

A compact solution for ion beam therapy with laser accelerated protons

“…Therefore, L-IBT poses a whole new set of challenges on both physical and biological levels. Laser-driven irradiation technology with all the necessary main components (such as high power laser system and laser target to produce the particle beam, and also beam transport and monitoring as well as dose delivery technique) has already been developed to perform in-vitro cell [26][27][28][29][30][31][32] and small animal [24,26] irradiation with low energy LAP within radiobiological experiments. These recent promising results encourage a go-ahead with further L-IBT solutions.…”

“…Therefore, new methods and techniques for beam transport, irradiation field formation and treatment planning [19][20][21], along with beam-monitoring, dosimetry and dose-controlled irradiation [22][23][24][25][26] are required. Moreover, determination of radio-biological effects induced by ultrashort intense particle bunches [26][27][28][29][30][31][32] is necessary. In addition to laser particle accelerator development, a parallel oncologyfocused research and development is essential to bring this highly promising technology to the clinics.…”

Preface: Physics of Cancer

“…These issues are addressed by Portz et al 10 ("A clinical data validated mathematical model of prostate cancer growth under intermittent androgen suppression therapy"), Cerofolini 11 ("Host-guest interaction in cancer and a reason for the poor efficiency of the immune system in its detection and termination") and Wiley and Haraldsen 12 ("The theory of modulated hormone therapy for the treatment of breast cancer in pre-and post-menopausal women"). The development of new technologies, such as laser driven ultra-fast high energy proton therapy by Doria et al 13 ("Biological effectiveness on live cells of laser driven protons at dose rates exceeding 10 9 Gy/s"), Alfano 14 explores using ultra-fast lasers to diagnose metastatic cancer cells ("Advances in ultrafast time resolved fluorescence physics for cancer detection in optical biopsy") while Solano et al 15 explore photo-acoustic imaging ("An experimental and theoretical approach to the study of the photoacoustic signal produced by cancer cells"). I was intrigued by the paper of Frieboes et al 16 which is a combination of sophisticated modeling of drug delivery to tumors coupled with new imaging technologies which will allow us to optimize modeling of drug delivery based upon observations.…”