Brachytherapy vs Radiotherapy: How Are They Different?

Brachytherapy places a radiation source inside or next to the treatment area, while radiotherapy directs radiation from a machine outside the body.

Both approaches are planned to target cancer cells while limiting exposure to nearby healthy tissue, but the suitable approach depends on the tumour's location, size, shape, and treatment goal. Some treatment plans use one approach, while others combine methods with surgery, medicines, or another form of radiation. The names describe delivery methods rather than a simple ranking.

Brachytherapy may be considered when the tumour can be reached safely with a catheter, applicator, needle, or implant. Bringing the source close to the target can allow the team to shape the dose around a small treatment area. The technique is used for selected cancers and may be given temporarily or through an implant that remains in place, depending on the plan.

Your team may discuss this option when a clearly defined target is near organs that need protection, or when focused treatment is part of the overall plan. The placement procedure, anaesthesia needs, and number of visits vary by treatment site.

Radiotherapy may be considered when an external beam can cover the target and any surrounding area the team needs to treat. It can be planned for a tumour that cannot be reached by an applicator or for an area requiring treatment from several directions. The machine does not need to enter the body, although you must remain in the planned position during delivery.

A course can involve repeated appointments, with the schedule set by the radiation oncologist. Radiotherapy may be used before or after surgery, alongside other treatment, or as the main local treatment, depending on the diagnosis and goal.

Both approaches can irritate normal tissue near the treatment area. Possible effects depend on the body region and may include tiredness, skin or lining irritation, swelling, discomfort, or changes in nearby organ function. Brachytherapy also has procedure-related considerations such as bleeding, infection, or soreness at the placement site. External radiotherapy may cause skin changes or symptoms in tissues included in the treatment field.

Tell the team about new or worsening symptoms, medicines, implanted devices, and any concerns about anaesthesia or positioning. They can explain which effects are expected for your treatment site and which need prompt contact.

Neither method may be suitable as the first treatment when the target cannot be reached safely, when a wider treatment approach is needed, or when the main goal is better addressed by surgery, cancer medicines, monitoring, or symptom care. A plan can also change if imaging shows that the tumour's position or extent differs from the initial assessment.

A different option does not mean that treatment has stopped. The oncology team may recommend another local or whole-body treatment, or combine approaches after reviewing pathology, scans, previous treatment, and your general health.

The team weighs the cancer type, exact location, size and shape of the target, nearby organs, prior radiation, and the purpose of treatment. They also consider whether the area can be reached for source placement, how well you can maintain the required position, and whether a procedure or repeated visits fit your health needs.

Useful questions include: What area will be treated? Why is this delivery method suited to my scan and pathology? Will treatment be temporary or repeated? What preparation, anaesthesia, appointments, and recovery should I expect? Which symptoms should prompt a call? Asking for the expected goal and alternatives can make the decision clearer.