Prospective RegIstry for Oncologic Reirradiation (PRIOR-DK) (PRIOR)

The study aims to provide a setup for collecting radiotherapy-related toxicity data, loco-regional control, and overall survival data for all Danish cancer patients undergoing reirradiation with high dose intention or with the aim of local tumour control; with the ultimate aim of providing safe reirradiation to a larger group of patients. To build a reirradiation cohort database for future research

Study Overview

• Status: Not yet recruiting
• Conditions: Radiotherapy Side Effect
• Intervention / Treatment: Radiation: Reirradiation

Detailed Description

Reirradiation of recurrent or new tumours has been associated with high rates of severe and even lethal toxicity in some previous reports [Andratscske2023]. This has led to many patients not being offered high dose reirradiation, even though they may potentially benefit from effective local treatment. Thus, it is extremely important to establish solid evidence of the risk of severe toxicity, to enable radiotherapy to be offered to these patients on an equal footing with patients treated for their first cancer.

This prospective registration study will form the basis of a database enabling us to learn more about which patients are suitable for reirradiation, optimal constraints for organs at risk in reirradiation, overall survival, etc.

• Study Type: Observational
• Enrollment (Estimated): 500

Contacts and Locations

• Study Contact: Name: Hanna R Mortensen, PhD, MD; Phone Number: 22154394 92432382; Email: hanna.mortensen@auh.rm.dk
• Study Contact Backup: Name: Camilla JS Kronborg, PhD, MD; Email: cam.kro@auh.rm.dk

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Probability Sample

Study Population

No guidelines are provided on the selection of patients for high dose reirradiation.

All patients are eligible for the database if treated with reirradiation with the aim of local control.

Description

Inclusion Criteria:

• High dose reirradiation (reirradiation type I or II or repeat organ irradiation delivered with the aim of local control)

Read Danish (for questionnaires + patient information)

Life expectancy due to age and co-morbidity of ≥6 months.

The general condition must be sufficient to tolerate persistent significant side effects

Histological or imaging verified loco-regional recurrence, solitary oligo metastasis or new primary

Age ≥18 years

Signed informed consent, updated annually

Expected follow up physical, by video, by phone or likely contact at a relevant oncological department

Available dose plan(s) from primary (and prior) radiotherapy course(s) (with 3D reconstruction of previous plans, available port film, or drawings). Multiple re-treatments are allowed (new inclusion and baseline registration)

Exclusion Criteria:

• The primary and reirradiation treatments may not be quasi-simultaneous (i.e. the two treatments should be planned independently)

Inability to attend full course of radiotherapy

Purpose of radiotherapy is ONLY palliation of symptoms

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Reirradiation; All patients treated with reirradiation with the aim of local control	Radiation: Reirradiation; reirradiation with all available modalities can be included

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Side effects	CTCAE side effects	5 years

Collaborators and Investigators

• Sponsor: University of Aarhus

Study record dates

Study Major Dates

• Study Start (Estimated): April 1, 2026
• Primary Completion (Estimated): March 31, 2032
• Study Completion (Estimated): March 31, 2037

Study Registration Dates

• First Submitted: April 7, 2026
• First Submitted That Met QC Criteria: April 7, 2026
• First Posted (Actual): April 14, 2026

Study Record Updates

• Last Update Posted (Actual): April 14, 2026
• Last Update Submitted That Met QC Criteria: April 7, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Wounds and Injuries; Radiation Injuries; Therapeutics; Radiotherapy; Retreatment; Re-Irradiation
• Other Study ID Numbers: PRIOR

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: A predefined central data analysis plan has not been established for this study. Instead, data analyses will primarily be undertaken within the framework of individual sub-projects, each of which must be reviewed and approved by the steering committee.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No