ICRT Brachytherapy Guidelines for Cervical and Endometrial Cancer

Primary Indications and Treatment Approaches

• The National Comprehensive Cancer Network recommends intracavitary brachytherapy as the standard of care for definitive treatment of intact cervical cancer and as essential adjuvant therapy for endometrial cancer with high-risk features 1, 2
• Brachytherapy is mandatory for all patients with intact cervical cancer receiving definitive radiotherapy, and cannot be replaced by external beam alone 1
• The American College of Radiology and the National Comprehensive Cancer Network explicitly state that highly conformal external beam therapies should not be used as routine alternatives to brachytherapy for central disease treatment 1

Applicator Selection and Technical Approach

• The American Brachytherapy Society recommends using an intrauterine tandem combined with vaginal colpostats (ovoids, ring, or cylinder) based on patient and tumor anatomy 1
• Applicator selection depends on individual anatomy and tumor characteristics, and should be guided by the National Comprehensive Cancer Network and the American Brachytherapy Society 1

Dosing Parameters and Standards

• The total combined dose from brachytherapy and external beam radiation to point A must reach at least 80 Gy for small tumors and ≥85 Gy for larger tumors, as recommended by the National Comprehensive Cancer Network and the American College of Radiology 1, 2
• The American College of Radiology recommends delivering approximately 45 Gy (range 40-50 Gy) to the primary tumor and regional lymphatics, with a brachytherapy boost of 30-40 Gy to point A (in LDR equivalent dose) 5, 2

Treatment Timing and Sequencing

• The National Comprehensive Cancer Network recommends completing the entire radiation course (external beam plus brachytherapy) within 8 weeks, as extending treatment beyond 6-8 weeks results in approximately 0.5-1% decrease in pelvic control and cause-specific survival for each extra day 1
• The American College of Radiology recommends administering concurrent cisplatin-based chemotherapy during external beam radiotherapy for most cervical cancer patients 1

Pre-Treatment Planning and Imaging

• The National Comprehensive Cancer Network recommends using MRI as the gold standard for soft tissue assessment, with 86% agreement with surgical pathology for tumor size 1
• The American College of Radiology recommends CT-based treatment planning with conformal blocking and dosimetry as standard care for external beam component 1

Special Populations and Considerations

• The National Comprehensive Cancer Network recommends vaginal cylinder brachytherapy as a boost to EBRT for cervical cancer with positive vaginal mucosal surgical margins, and optional vaginal brachytherapy for endometrial cancer stage IIA disease 5, 3