Radiation Therapy in Localized Colon Cancer

Indications for Radiation

The National Comprehensive Cancer Network recommends radiation therapy for T4 tumors with penetration to fixed structures to reduce the risk of local recurrence 1, 2
Radiation may be considered for patients with positive or close surgical margins to control residual disease 2
Patients with tumor perforation in the tumor area may benefit from radiation to reduce the risk of local recurrence 2

Radiation fields should include the tumor bed as defined by preoperative imaging and/or surgical clips 2
The typical radiation dose is 45-50.4 Gy delivered in 1.8-2.0 Gy fractions 2, 4
Radiation is generally administered postoperatively with concurrent 5-FU-based chemotherapy 2
Conformal beam radiation should be routinely used, and intensity-modulated radiotherapy should be reserved for unique clinical situations including re-irradiation 2

The current standard of care for localized colon cancer includes surgical resection followed by adjuvant chemotherapy for high-risk disease, with radiation therapy reserved for specific high-risk situations 1, 2, 5
The European Society for Medical Oncology recommends complete mesocolic excision with adequate lymph node sampling (at least 12 nodes) 5
Adjuvant chemotherapy is recommended for stage III and high-risk stage II disease 2, 5
The National Comprehensive Cancer Network recommends radiation therapy only for T4 tumors with penetration to fixed structures or other specific high-risk features 1, 2