Weekly Cisplatin — Alongside Radiotherapy

Some concurrent chemoradiation protocols do use cisplatin every three weeks at a higher dose, and for certain cancer types that schedule is preferred. The weekly lower-dose schedule is more commonly used when daily radiation is running simultaneously, because it is generally better tolerated alongside the cumulative fatigue and local effects of radiation. Which schedule applies to you depends on your cancer type, kidney function, and the specific protocol your oncologist is following. If your chart shows a different interval, ask your team which protocol applies to you and why it was chosen.

Most people do not feel the cisplatin during the infusion itself. The day is longer than a usual radiation visit because of the IV fluids given before and after. Nausea is the most common thing people notice in the hours that follow, and you will receive antiemetic medicine before the cisplatin starts to reduce this. If nausea is not adequately controlled, tell your team — there are several effective medicines and the combination can be adjusted.

Your team will check kidney function and blood counts before most cisplatin doses. Cisplatin is cleared through the kidneys, and a dose may be held if your kidney function has changed significantly. Blood counts are checked because cisplatin can affect the bone marrow. Magnesium and other electrolytes, which cisplatin can lower, may also be monitored. A hearing test is often arranged before treatment begins and may be repeated during or after it, because cisplatin can cause hearing loss.

Cisplatin travels through the bloodstream and reaches tissues throughout the body, not only the tumour. This is what allows it to sensitise cancer cells to radiation — and it is also why it can affect the kidneys, hearing, and nerves elsewhere. The radiation, by contrast, is targeted to a specific area. Both effects — the whole-body effect of cisplatin and the local effect of radiation — are part of what your team monitors throughout treatment.

Eating well is important and often harder than expected during chemoradiation. Nausea from cisplatin and soreness from radiation can both reduce appetite. If radiation is being given to the head, neck, or throat, swallowing may become increasingly difficult over the weeks of treatment. A dietitian is typically part of the care team for head and neck chemoradiation. Tell your team early if you are losing weight or struggling to eat — there are practical measures that help, and nutrition during treatment affects how you recover.

A dose may be held if kidney function, hearing, or blood counts fall outside the safe range. Whether a held dose is given later, skipped, or whether treatment continues with radiation alone depends on why it was held and how quickly values return to an acceptable level. Your oncologist will explain the decision and what it means for the overall plan. Holding a dose when it is the right clinical decision is not a setback — it is part of managing the treatment safely.