adenocarcinoma of the rectum Rectal cancer rectal tumor
Conditions
Interventions
HDR endorectal brachytherapy: 4 fractions of 6.5 Gy within 7 days. TME surgery
will be performed 8 weeks after the first fraction of radiotherapy.
Sponsors
Leids Universitair Medisch Centrum
Eligibility
Age
18 Years to 99 Years
Inclusion criteria
Inclusion criteria: * Adenocarcinoma of the rectum * Clinically T1-2N1 or T3N0 with > 5 mm extramural invasion or T3N1 tumor * No threatened or involved mesorectal fascia on MRI * Eligible for 5x5 Gy according to the Dutch guidelines * Cranial edge of the tumor below sigmoid curvature on MRI * Caudal margin of the tumor above dentate line (endoscopic observation) * Tumors with an adequate (>2 cm) lumen to allow the positioning of the applicator (e.g. non obstructive tumor) * WHO performance status 0-2 (Appendix B) * Age > 18 years
Exclusion criteria
Exclusion criteria: * Extramesorectal (e.g. iliac, lateral) pelvic lymph node involvement * Previous pelvic irradiation * Extension of tumor into the anal canal * Contra-indication for endoscopic placement of gold-markers such as coagulopathy (prothrombin time 50 seconds) or anticoagulantia (marcoumar, sintrom or new oral anticoagulants) that cannot be stopped. * Contra-indications for a MRI exam with Gadolinium according to the institutional policy * Pregnancy
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| To establish an image-guided brachytherapy procedure for rectal cancer that is feasible for use in a multicenter randomized trial. The protocol will be declared feasible and robust for multicenter use if in both institutes 4/5 patients have been treated without defined violations. The following events are considered violations: * Patients not completing the brachytherapy (i.e. 4 fractions) due to non-compliance * Geographic miss of the tumor bed (as determined by review by PI) * Inability to reproduce the planning position of the applicator during the treatment (as determined by review by PI) * Inappropriate assignment of the planned first dwell position on the planning CT data set (more than 4 times the slice thickness; i.e. more than 8 mm in cranial caudal direction) * Incorrect calculation of the indexer length on treatment days * Improper channel assignment during a daily treatment * Inappropriate assignment of the channel rotational position (more than ± 5o, or more than 1.5 mm misalignment between x-ray markers in channels 1 and 5 as seen on a daily radiograph) * Planning criteria not met: o 90% of the clinical target volume will receive at least 90% of the prescribed dose (D90> 23,4 Gy). o Organs at risk: cumulative D2cc (EQD2, using */*=3): bladder | — |
Secondary
| Measure | Time frame |
|---|---|
| * Evaluation of willingness of patients to undergo an image-guided brachytherapy procedure. * Refinement of repeated quantitative MR imaging for response monitoring for later use in the randomized trial. * Definition of an optimal PA procedure for histological analysis of whole mount slides, for later use in the randomized trial * Development of methods for registration of MRI data to pathology slides | — |
Countries
Netherlands
Outcome results
None listed