Three-dimensional High Dose Rate Intracavitary Image-guided Brachytherapy for the Treatment of Cervical Cancer Using a Hybrid Magnetic Resonance Imaging/Computed Tomography Approach: Feasibility and Early Results

• Published in: Clinical oncology (Royal College of Radiologists (Great Britain)) 2011-12, Vol.23 (10), p.685-690
• Main Authors: Beriwal, S, Kannan, N, Kim, H, Houser, C, Mogus, R, Sukumvanich, P, Olawaiye, A, Richard, S, Kelley, J.L, Edwards, R.P, Krivak, T.C
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aged, 80 and over; Brachytherapy - methods; Cervix; Cisplatin - administration & dosage; Combined Modality Therapy; Female; Follow-Up Studies; GEC-ESTRO; HDR; Hematology, Oncology and Palliative Medicine; Humans; Imaging, Three-Dimensional - methods; Magnetic Resonance Imaging - methods; Middle Aged; MRI; Neoplasm Staging; Radiology; Radiotherapy Dosage; Radiotherapy Planning, Computer-Assisted; Tomography, X-Ray Computed - methods; Uterine Cervical Neoplasms - diagnostic imaging; Uterine Cervical Neoplasms - drug therapy; Uterine Cervical Neoplasms - pathology; Uterine Cervical Neoplasms - radiotherapy
• ISSN: 0936-6555; 1433-2981
• DOI: 10.1016/j.clon.2011.08.007

Abstract Aims To evaluate the feasibility and outcome of image-guided brachytherapy (IGBT) for treating cervical cancer using magnetic resonance imaging (MRI)-based planning for the first fraction followed by computed tomography (CT)-based planning for subsequent fractions. Materials and methods Forty-four patients with cervical cancer were treated with three-dimensional high dose rate IGBT. The brachytherapy dose was 5.0–6.0 Gy × five fractions. All but five patients received concurrent weekly cisplatinum at 40 mg/m2 . All patients received external beam radiotherapy (EBRT) with a median dose of 45 Gy over 25 fractions. Total doses for the high-risk clinical target volume (HRCTV) and organs at risk, including the rectum, bladder and sigmoid, from EBRT and brachytherapy were summated and normalised to a biologically equivalent dose of 2 Gy per fraction (EQD2 ). At 3 months after therapy, any early response was assessed with positron emission tomography (PET)/CT imaging. Results The mean D90 for the HRCTV was 83.3 (3.0) Gy. The mean 2 cm3 dose to the bladder, rectum and sigmoid colon organs was 79.7 (5.1), 57.5 (4.4) and 66.8 (5.7) Gy, respectively. All but one (2.3%) patient had a complete response. Follow-up PET/CT was carried out in 41 (93.0%) patients, of whom 38 (92.5%) had a complete response. Of the 38 patients with a complete response on PET/CT, two had local recurrences at 6 and 8 months, respectively. Actuarial 2 year local control, disease-specific and overall survival rates were 88, 85 and 86%, respectively. Conclusion This is the first report of three-dimensional high dose rate IGBT for the treatment of cervical cancer using a hybrid MRI/CT approach. Early results have shown the feasibility of this approach with excellent local control. Additional studies are needed to assess long-term outcomes of local control and associated morbidities.