Radiation Therapy, Systemic Therapy, and Treatment Sequencing
Overview
This domain covers the principles of radiation therapy (external beam and brachytherapy), chemotherapy, targeted therapy, and immunotherapy for gynecologic cancers, and the sequencing of these modalities. Key concepts: Cervical cancer: concurrent chemoradiation (cisplatin) with brachytherapy for locally advanced; immunotherapy for PD-L1 positive. Endometrial cancer: surgery first; adjuvant radiation or chemotherapy based on risk; immunotherapy for advanced/recurrent. Ovarian cancer: surgery followed by platinum-based chemotherapy; maintenance PARP inhibitors for BRCA-mutated; bevacizumab. Vulvar cancer: radiation or chemoradiation for advanced; immunotherapy for recurrent. Treatment sequencing: neoadjuvant chemotherapy for ovarian cancer in selected patients; adjuvant therapy after surgery. Radiation techniques: 3D conformal, IMRT, brachytherapy.
Traps
Questions often test the standard of care for each stage. A common trap is the use of concurrent chemoradiation for cervical cancer (not sequential). Another trap is the indication for PARP inhibitors in ovarian cancer (BRCA mutation or HRD). Also, immunotherapy is approved for recurrent/advanced cervical and endometrial cancers. Be clear on the sequence: surgery first for endometrial and vulvar; chemoradiation for cervical; surgery then chemotherapy for ovarian.
Worked Example
A 50-year-old with stage IIB cervical cancer. What is the standard treatment? Concurrent chemoradiation with cisplatin and brachytherapy. Rule of thumb: Locally advanced cervical cancer is treated with primary chemoradiation, not surgery.