Understanding How Cancer Responds to Radiotherapy: What Alpha and Beta Mean

When someone receives radiotherapy, the goal is to destroy cancer cells while protecting healthy tissues. However, not all tumors react in the same way to radiation. Some are very sensitive and controlled with small doses, while others need higher or more concentrated doses to achieve the same effect.
Researchers from the Academic Medical Center of Amsterdam reviewed over sixty clinical studies to explore this question. Their work focused on two key biological parameters known as alpha (α) and beta (β), which describe how sensitive a tumor is to radiation.

The study found that tumor type and histology—that is, how the cancer cells look under the microscope—strongly influence radiosensitivity. For instance, prostate and breast cancers (usually adenocarcinomas) have low α/β ratios, meaning they respond well to small doses delivered in multiple sessions. By contrast, head and neck, bladder, or cervical cancers (mostly squamous cell tumors) tend to have high α/β ratios, requiring more intense doses to achieve tumor control.

The authors emphasized that these values are not fixed. They vary depending on the tumor’s stage, the type of radiotherapy (external beam or brachytherapy), and the mathematical model used. Therefore, radiation oncologists should consider a range of α/β values rather than a single number when designing a treatment plan. This approach helps tailor therapy to each patient, improving safety and effectiveness.

For patients, this research brings a reassuring message: modern radiotherapy is increasingly personalized. By understanding how each type of cancer responds biologically to radiation, doctors can fine-tune doses to maximize cure rates while minimizing side effects. In essence, the alpha and beta parameters represent the science behind today’s more precise, safer, and more compassionate cancer care.