Clinical Research Directory

Inclusion Criteria: Initial phase (standard phase). These criteria represent the conditions for which preoperative chemoradiotherapy treatment for rectal cancer is clinically indicated 1. Histologically confirmed rectal adenocarcinoma 2. Microsatellite status: stable 3. Stage T2N0 if lower rectal lesions are candidates for subsequent intersphincteric resection or abdominoperineal amputation with permanent colostomy 4. Stage T3-T4N0 or any T with positive lymph nodes 5. Lower margin of lesion no more than 12 cm from anal verge Adaptive radiotherapy phase (experimental phase) 6. ERI\_TCP \< 32.6 calculated as follows: ERITCP=-ln\[(1-(Vmid/Vpre)\]Vpre where Vpre is the volume of the rectal tumor pre-therapy, Vmid is the volume of the residual tumor still visible in the images of the MR intermediate to RT) 7. Lower margin of rectal lesion at least 1 cm from surgical resection line on images of the intermediate smc MRI 8. ECOG (Eastern Cooperative Oncology Group) Performance Status ≤ 2 9. Age: 18-80 years 10. Written informed consent Exclusion Criteria: 1. Distant metastases 2. Previous cancer excluding non-melanoma skin cancer diagnosed less than 5 years before rectal cancer appearance 3. Previous chemotherapy or radiotherapy to the pelvis 4. Contraindications to radiotherapy: active ulcerative colitis 5. Contraindications to chemotherapy: NE\<1.5x10/L, Plt \< 100x10/L), creatinine \>1,5mg/dl, bilirubin \> 2mg/dl, AST/ALT \> 3x normal upper limit, significant cardiac disease, peripheral neuropathy. 6. Pregnancy 7. Breastfeeding