PURPOSE: Limited access to MRI has restricted implementation of MRI-based image-guided brachytherapy (IGBT) in line with GEC-ESTRO guidelines in many centers. This work reports our experience using an alternative CT/MRI based (hybrid) approach for IGBT, dosimetry comparisons, and its impact on long-term clinical outcome and major @entity137 . METHODS AND MATERIALS: Seventy-six @entity1 diagnosed with locally advanced @entity5 between May 2008 and May 2012 treated with IGBT were analyzed. The hybrid approach is the default IGBT approach during this study period. Forty-nine had hybrid approach and 27 @entity1 had "3-fraction conformal MRI" approach (17 within EMBRACE study). Treatment consisted of 48  Gy in 24 fractions of conformally planned external beam radiotherapy with weekly @entity900 followed by three weekly fractions of brachytherapy to high-risk clinical target volume (HR-CTV). All @entity1 have a prebrachytherapy MRI 4  days before treatment and with the applicators in place on Fraction 1. MRI only or CT is used for subsequent fractions. Using image registration techniques and the assumption that the HR-CTV is fixed with respect to the applicator, the HR-CTV from MRI at Fraction 1 is transferred onto subsequent fraction CT image sets for the hybrid approach. RESULTS: Median follow-up was 41  months (range, 23-71  months). Excellent 3-year local control, overall progression-free survival, and overall survival of 92.6%, 78.8%, and 77.7% were seen with the hybrid approach and 92.2%, 66.3%, and 69.6% with a 3-fraction conformal MRI approach, respectively. Dosimetry achieved and late @entity137 rates were comparable in the two groups. CONCLUSIONS: Hybrid IGBT in locally advanced @entity5 offers an alternative approach when access to MRI restricts implementation of IGBT.

Hybrid (CT/MRI based) vs. MRI only based image-guided brachytherapy in XXXX : Dosimetry comparisons and clinical outcome.

@entity1 :: ('9606', 'Species') :: ['patients'] @entity137 :: ('MESH:D064420', 'Disease') :: ['toxicity'] @entity5 :: ('MESH:D009369', 'Disease') :: ['cervical cancer'] @entity900 :: ('MESH:D002945', 'Chemical') :: ['cisplatin']
@entity5 :: (MESH:D009369,Disease) :: ['cervical cancer']
