  Radiotherapy using very-high-energy electron (VHEE) beams (50-300 MeV) has
attracted considerable attention due to its advantageous dose deposition
characteristics, enabling deep penetration and the potential for ultra-high
dose rate treatment. One promising approach to compactly delivering these high
energy electron beams in a cost-effective manner is laser wakefield
acceleration (LWFA), which offers ultra-strong accelerating gradients. However,
the transition from this concept to a functional machine intended for tumor
treatment is still being investigated. Here we present the first self-developed
prototype for LWFA-based VHEE radiotherapy, exhibiting high compactness
(occupying less than 5 square meters) and high operational stability (validated
over a period of one month). Subsequently, we employed this device to irradiate
a tumor implanted in a mouse model. Following a dose delivery of $5.8\pm0.2$ Gy
with precise tumor conformity, all irradiated mice exhibited pronounced control
of tumor growth. For comparison, this tumor-control efficacy was similar to
that achieved using commercial X-ray radiotherapy equipment operating at
equivalent doses. These results demonstrate the potential of a compact
laser-driven VHEE system for preclinical studies involving small animal models
and its promising prospects for future clinical translation in cancer therapy.
