Development and clinical implementation of a new template for MRI-based intracavitary/interstitial gynecologic brachytherapy for locally advanced cervical cancer: from CT-based MUPIT to the MRI compatible Template Benidorm. Ten years of experience

Abstract

PurposeTo study outcome and toxicity in 59 patients with locally advanced cervix carcinoma treated with computed tomography (CT)-based Martinez universal perineal interstitial template (MUPIT) and the new magnetic resonance imaging (MRI)-compatible template Benidorm (TB).Material and methodsFrom December 2005 to October 2015, we retrospectively analyzed 34 patients treated with MUPIT and 25 treated with the TB. Six 4 Gy fractions were prescribed to the clinical target volume (CTV) combined with external beam radiotherapy (EBRT). The organs at risk (OARs) and the CTV were delineated by CT scan in the MUPIT implants and by MRI in the TB implants. Dosimetry was CT-based for MUPIT and exclusively MRI-based for TB. Dose values were biologically normalized to equivalent doses in 2 Gy fractions (EQD2).ResultsMedian CTV volumes were 163.5 cm3 for CT-based MUPIT (range 81.8-329.4 cm3) and 91.9 cm3 for MRI-based TB (range 26.2-161 cm3). Median D90 CTV (EBRT + BT) was 75.8 Gy for CT-based MUPIT (range 69-82 Gy) and 78.6 Gy for MRI-based TB (range 62.5-84.2 Gy). Median D2cm3 for the rectum was 75.3 Gy for CT-based MUPIT (range 69.8-132.1 Gy) and 69.9 Gy for MRI-based TB (range 58.3-83.7 Gy). Median D2cm3 for the bladder was 79.8 Gy for CT-based MUPIT (range 71.2-121.1 Gy) and 77.1 Gy for MRI-based TB (range 60.5-90.8 Gy). Local control (LC) was 88%. Overall survival (OS), disease free survival (DFS), and LC were not statistically significant in either group. Patients treated with CT-based MUPIT had a significantly higher percentage of rectal bleeding G3 (p = 0.040) than those treated with MRI-based TB, 13% vs. 2%.ConclusionsTemplate Benidorm treatment using MRI-based dosimetry provides advantages of MRI volume definition, and allows definition of smaller volumes that result in statistically significant decreased rectal toxicity compared to that seen with CT-based MUPIT treatment.

Long-term effectiveness and safety of image-based, transperineal combined intracavitary and interstitial brachytherapy in treatment of locally advanced cervical cancer

“…However, in the present age of volume-based implants, the use of tandem does not seem to increase the toxicities. Villalba documented 2% grade 3 rectal bleeds with the use of the IC-ISBT system compared with 13% in the ISBT patients (15). Our analysis, too, did not reveal any difference in late sequelae between the two BT techniques ( p 5 0.86).…”

“…(1) It helps in straightening and stabilizing the uterus for the subsequent placement of the needles (1). (2) It addresses the superior intrauterine extension of the tumor, which cannot be accessed adequately with the straight and rigid ISBT needles (15). 3It forms a high-dose region in the cervix, where more resistant tumor cells may reside (2).…”

Three-dimensional-guided perineal-based interstitial brachytherapy in cervical cancer: A systematic review of technique, local control and toxicities

“…1). Nineteen studies met the inclusion criteria and were fully reviewed for data extraction [11,[13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30]. Eight studies were excluded after full review: three had no 3D-planning; one used P-ISBT as neoadjuvant treatment, one reported dosimetric outcomes only (no clinical data), one had no primary cervix cancers treated as definitive therapy, one did not use perineal ISBT (intravaginal) and another had a more updated series which was included in our review.…”

“…All studies used trans-perineal needles. Plastic catheters were used in nine studies [11,13,15,18,20,22,24,25,30], metallic in five [14,16,17,23,27]. Four studies did not mention needle characteristics [19,21,28,29] and one used either plastic or metallic needles [26].…”

The Medanta AOLO template for locally advanced cancer cervix brachytherapy: design and clinical implementation

“…nous development of applicator and its clinical use has been mentioned previously [10]. A recent survey in India shows that while more than 50% centers use CT as volumetric imaging, 87% centers do not perform any interstitial procedures [11].…”