Pencil Beam Proton Therapy for Pelvic Recurrences in Rectal Cancer Patients Previously Treated With Radiotherapy

Study Overview
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Brief Summary
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Study design: A prospective phase II, non-randomized observational study of dose-escalated pencil beam proton therapy re-irradiation for pelvic recurrences from rectal cancer. Re-irradiation is either a part of neo-adjuvant treatment or as a definitive treatment strategy for un-resectable recurrences.

Official Title
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Pencil Beam Proton Therapy for Pelvic Recurrences in Rectal Cancer Patients Previously Treated With Radiotherapy

Conditions
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Rectal Cancer Recurrent

Intervention / Treatment
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* Radiation: Pencil beam proton radiotherapy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: • Locally recurrent rectal cancer. Bioptically verified (adenocarcinoma ) Available dose plan from primary radiotherapy Previous pelvic RT (>30Gy EQD2) Evaluated in MDT-conferences (Herlev, Aarhus) Age>18 years PS 0-2 Adequate organ function Informed consent Exclusion Criteria: Non-resectable distant metastases (PET-CT) Unable to undergo MRI, PET-CT Inability to attend full course radiotherapy and follow up in the out patient clinic.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Neo-adjuvant pencil beam proton therapy: 55 Gy(RBE)/44fx (1.25 Gy per fraction), two daily<br> | Radiation: Pencil beam proton radiotherapy<br>* Doseescalated pencil beam proton Therapy<br>|
| Experimental: Definitive arm pencil beam proton therapy: 57.5-65Gy(RBE)/46-52 fx (1.25 per fraction) two daily<br> | Radiation: Pencil beam proton radiotherapy<br>* Doseescalated pencil beam proton Therapy<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| R0-resection | Neo-adjuvant treatment: Rate of pathological complete resection (R0) | 5-6 years | 
| 1-year local control | Definitive treatment: Rate of 1-year local control rates evaluated by CT or MRI. | 6-7 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Local recurrence | Local re-recurrence determined by imaging 6, 12 and 24 month post treatment | 6-8 years | 
| Disease free survival | Disease free survival, defined as time from first day of treatment until first documented sign of disease or death from any course | 10 years | 
| Overall survival | Overall survival defined as time from first day of treatment to death from any cause | 10 years | 
| Toxicity | Toxicity evaluated by NCI-CTCAE v. 5.0 acute and chronic | 5-7 years | 
| Patient reported outcomes | Quality of life assessment by EORTC QLQ-c30, QLQ-CR29, supplementary EORTC items, and LARS score. Acute and chronic | 5-7 year |