Methods, safety, and early clinical outcomes of dose escalation using simultaneous integrated and sequential boosts in patients with locally advanced gynecologic malignancies

Objective To evaluate the safety of dose escalated radiotherapy using a simultaneous integrated boost technique in patients with locally advanced gynecological malignancies.Methods Thirty-nine women with locally advanced gynecological malignancies were treated with intensity modulated radiation therapy utilizing a simultaneous integrated boost (SIB) technique for gross disease in the para-aortic and/or pelvic nodal basins, sidewall extension, or residual primary disease. Women were treated to 45 Gy in 1.8 Gy fractions to elective nodal regions. Gross disease was simultaneously treated to 55 Gy in 2.2 Gy fractions (n = 44 sites). An additional sequential boost of 10 Gy in 2 Gy fractions was delivered if deemed appropriate (n = 29 sites). Acute and late toxicity, local control in the treated volumes (LC), overall survival (OS), and distant metastases (DM) were assessed.Results All were treated with a SIB to a dose of 55 Gy. Twenty-four patients were subsequently treated with a sequential boost to a median dose of 65 Gy. Median follow-up was 18 months. Rates of acute > grade 2 gastrointestinal (GI), genitourinary (GU), and hematologic (heme) toxicities were 2.5%, 0%, and 30%, respectively. There were no grade 4 acute toxicities. At one year, grade 1-2 late GI toxicities were 24.5%. There were no grade 3 or 4 late GI toxicities. Rates of grade 1-2 late GU toxicities were 12.7%. There were no grade 3 or 4 late GU toxicities.Conclusion Dose escalated radiotherapy using a SIB results in acceptable rates of acute toxicity.