Cancer radiotherapy based on femtosecond IR laser-beam filamentation yielding ultra-high dose rates and zero entrance dose

Abstract

Since the invention of cancer radiotherapy, its primary goal has been to maximize lethal radiation doses to the tumor volume while keeping the dose to surrounding healthy tissues at zero. Sadly, conventional radiation sources (γ or X rays, electrons) used for decades, including multiple or modulated beams, inevitably deposit the majority of their dose in front or behind the tumor, thus damaging healthy tissue and causing secondary cancers years after treatment. Even the most recent pioneering advances in costly proton or carbon ion therapies can not completely avoid dose buildup in front of the tumor volume. Here we show that this ultimate goal of radiotherapy is yet within our reach: Using intense ultra-short infrared laser pulses we can now deposit a very large energy dose at unprecedented microscopic dose rates (up to 1011 Gy/s) deep inside an adjustable, well-controlled macroscopic volume, without any dose deposit in front or behind the target volume. Our infrared laser pulses produce high density avalanches of low energy electrons via laser filamentation, a phenomenon that results in a spatial energy density and temporal dose rate that both exceed by orders of magnitude any values previously reported even for the most intense clinical radiotherapy systems. Moreover, we show that (i) the type of final damage and its mechanisms in aqueous media, at the molecular and biomolecular level, is comparable to that of conventional ionizing radiation, and (ii) at the tumor tissue level in an animal cancer model, the laser irradiation method shows clear therapeutic benefits.

Synthesis of Hydrophilic and Hydrophobic Carbon Nanoparticles from Benzene/Water Bilayer Solution with Femtosecond Laser Generated Plasma Filaments in Water

“…In the case of laser-induced filaments, high concentrations of reactive species (not only OH but also H, and O) are expected in a well-confined volume. 57 Once phenol, biphenyl, the secondary, and the further products are formed, it would be exposed to high-density reactive species inside and around the filament. As the molecular size becomes larger, very many possible reaction pathways open inside and outside of the filament.…”

Loss of Cellular Transformation Efficiency Induced by DNA Irradiation with Low-Energy (10 eV) Electrons

“…Such knowledge is essential for understanding the details of energy deposition in cells by IR and should lead to the development of more efficient protocols for cancer treatment with radiotherapy. 81,82 Such details may be particularly valuable for heavy ion therapy, where very high LET particles generate along their path a high density of LEEs, 83 which, according to the present results, have a propensity to create less reparable cluster damages. Impact of 10 eV-electron irradiation on transformation efficiency.…”

Diffractive control of 3D multifilamentation in fused silica with micrometric resolution

“…It is wellknown that a suited control over the spatial and temporal properties of ultrashort pulses allows manipulating non-linear phenomena for developing multiple tasks, including two-photon microscopy [1], cancer therapy [2], micro-processing of materials [3], or non-linear spectroscopy [4]. Other settle-down applications i.e., for getting the initial seed in ultrafast optical parametric amplifiers [5], or for synthesizing high harmonics [6] have also been reported.…”