On 15 February 2022, N. Hoekstra will defend her PhD dissertation, entitled: ‘High-precision Adjuvant Radiotherapy for Early-stage Breast Cancer Patients to Reduce Toxicity and Improve Survival’.
- Promotor
- Promotor
- Co-promotor
- Date
- Tuesday 15 Feb 2022, 13:00 - 14:30
- Type
- PhD defence
- Space
- Professor Andries Querido room
- Building
- Education Center
- Location
- Erasmus MC
Women diagnosed with early-stage breast cancer have an excellent survival after treatment. Unfortunately, the treatment can cause potentially lethal toxicities. This thesis describes ways to reduce long-term toxicities of radiation treatment given for early-stage breast cancer. There will always be a low dose of irradiation in the surrounding tissues. The most important toxicities are an increased risk of cardiovascular disease and the induction of second lung cancers.
Our work showed that the risk of induced tumors is lower after irradiating only the area of the breast where the tumor was, partial breast irradiation, compared to irradiating the entire breast. The risk can be reduced even more by adapting the technique used to deliver the irradiation. Prioritizing protection of the lungs and using beams from different angles decrease the risk of lung cancer induction. It is also important to deliver the irradiation precisely, to prevent damage in surrounding tissues. We conclude that the motion of the treatment target is mostly due to a slow drift of the patients. Breathing causes only limited motion. An additional factor to take into account is the variation in position and anatomy between treatment fractions of a single patient. We show a method to define the safety margin that compensates for uncertainties and motion during partial breast irradiation. This ensures optimal efficacy of the treatment while maximally protecting the surrounding tissues.
The PhD defences will not take place publicly in the usual way. A live stream link has been provided to candidate. The ceremony will begin exactly at 13.00.
