How long does radiotherapy take to work for ductal carcinoma in situ?

DCIS is abnormal cell growth confined to the milk ducts. Radiotherapy is usually given after breast-conserving surgery to treat breast tissue where microscopic abnormal cells could remain. The radiation dose is delivered in planned appointments, and the biological effect continues after each session. A scan or examination immediately after treatment cannot always show the full response.

Follow-up may include checking the treated breast, discussing skin or breast changes, and arranging mammography at the interval chosen by your breast team. The purpose is to look for healing and any new or persistent changes, not to judge progress by symptoms alone.

Attend every scheduled appointment unless your radiotherapy team changes the plan. Wash the treated area gently, avoid rubbing or applying unapproved products, and tell the team about redness, soreness, swelling, or broken skin. Fatigue can build during a course and may ease gradually afterward, so pace activities and accept practical help.

Keep your follow-up appointments even if the breast feels normal. Bring a list of medicines and any questions about future mammograms, breast awareness, or whether additional treatment is planned.

Contact your radiotherapy team promptly if skin becomes very painful, blistered, or open; if swelling suddenly worsens; or if you develop fever or feel acutely unwell. Seek urgent help for severe breathing difficulty, chest pain, or sudden collapse. These symptoms need assessment rather than waiting for the next appointment.

Ask when your first post-treatment breast examination and mammogram are expected, what changes are normal while the skin heals, and how your team will assess the treated area. You can also ask whether the radiotherapy schedule may change and who to call outside clinic hours.