Registry Maastro Applicator

Standard treatment for rectal cancer usually involves surgical removal of the tumor. Depending on the tumor's characteristics, patients may first receive neoadjuvant therapy such as radiotherapy, chemoradiotherapy, or total neoadjuvant treatment (TNT). These treatments aim to improve oncological outcomes and can lead to a complete response (CR) in about 10-40% of patients. When a CR occurs, patients may choose a watch-and-wait strategy, which avoids surgery and improves quality of life by preventing complications such as incontinence or the need for a stoma.

Increasing the radiation dose improves the chance of achieving a CR. Endoluminal boost techniques-high-dose-rate (HDR) brachytherapy and contact X-ray radiotherapy (CXRT)-allow a highly localized radiation boost. CXRT has shown higher CR rates than external beam radiotherapy (EBRT) boosts (81% vs. 60%). However, widespread use of endoluminal boosting is limited by the high cost of CXRT equipment and the less favorable dose distribution of HDR brachytherapy.

To overcome these limitations, MAASTRO, in collaboration with Varian Inc., developed a new HDR rectal brachytherapy applicator that delivers a dose profile similar to CXRT. The applicator has received CE certification and is now available for clinical use. A recent clinical trial confirmed that treatment with this applicator is clinically feasible. As a result, MAASTRO HDR treatment is now part of standard care.

To improve understanding of treatment outcomes and optimize future strategies, a prospective observational cohort study has been initiated.This project is designed to continuously include new patients and will provide an ongoing source for multiple future studies

Inclusion criteria

• Age ≥ 18 years.
• Histological proof of rectal cancer, or a strong suspicion after imaging.
• Treatment with MAASTRO HDR rectal applicator
• Informed consent for longitudinal observational data collection.

Exclusion criteria

• Mentally incompetent patients.