RadLite: Multi-Task LoRA Fine-Tuning of Small Language Models for CPU-Deployable Radiology AI
This work addresses the challenge of deploying large language models in resource-constrained clinical settings due to their high computational demands. The authors propose RadLite, a framework that leverages LoRA-based fine-tuning of compact models—Qwen2.5-3B and Qwen3-4B—combined with multi-task training and GGUF quantization to enable efficient inference across nine radiology tasks. This study demonstrates for the first time that lightly fine-tuned small models can effectively perform multi-task radiological analysis and operate entirely on CPU with modest memory requirements (1.8–2.4 GB) and throughput of 4–8 tokens per second. Compared to zero-shot baselines, RadLite achieves substantial improvements: +53% in RADS classification accuracy, +60% in natural language inference (NLI), and +89% in N staging. Furthermore, ensembling Qwen2.5 and Qwen3 yields complementary strengths and state-of-the-art performance in structured generation and information extraction tasks.