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MITHRA - multiparametric MR/CT image adapted brachytherapy (MR/CT-IABT) in anal canal cancer: a feasibility study.

Tagliaferri L, Manfrida S, Barbaro B, Colangione MM, Masiello V, Mattiucci GC, Placidi E, Autorino R, Gambacorta MA, Chiesa S, Mantini G, Kovács G, Valentini V - J Contemp Brachytherapy (2015)

Bottom Line: The dosimetric analysis resulted in a median of V200, V150, V100, V90, V85, respectively of 24.6%, 53.4%, 93.5%, 97.6%, and 98.7%.The median coverage index (CI) was 0.94, the median dose homogeneity index (DHI) was 0.43, the median dose non-uniformity ratio (DNR) resulted 0.56, the median overdose volume index (ODI) was 0.27.Magnetic resonance can also have biological advantages compared to the US.

View Article: PubMed Central - PubMed

Affiliation: Radiation Oncology Department, Gemelli-ART, Università Cattolica del Sacro Cuore, Rome, Italy.

ABSTRACT

Purpose: The aim of this study is to test a novel multiparametric imaging guided procedure for high-dose-rate brachytherapy in anal canal cancer, in order to evaluate the feasibility and safety.

Material and methods: For this analysis, we considered all consecutive patients who underwent magnetic resonance/computed tomography image adapted brachytherapy (MR/CT-IABT) treated from February 2012 to July 2014. To conduct this project, we formed a working group that established the procedure and identified the indicators and benchmarks to evaluate the feasibility and safety. We considered the procedure acceptable if 90% of the indicators were consistent with the benchmarks. Magnetic resonance imaging with contrast and diffusion weighted imaging were performed with an MRI-compatible dummy applicator in the anus to define the position of the clinical target volume disease and biological information. A pre-implantation treatment planning was created in order to get information on the optimal position of the needles. Afterwards, the patient underwent a simulation CT and the definite post-implantation treatment planning was created.

Results: We treated 11 patients (4 men and 7 women) with MR/CT-IABT and we performed a total of 13 procedures. The analysis of indicators for procedure evaluation showed that all indicators were in agreement with the benchmark. The dosimetric analysis resulted in a median of V200, V150, V100, V90, V85, respectively of 24.6%, 53.4%, 93.5%, 97.6%, and 98.7%. The median coverage index (CI) was 0.94, the median dose homogeneity index (DHI) was 0.43, the median dose non-uniformity ratio (DNR) resulted 0.56, the median overdose volume index (ODI) was 0.27. We observed no episodes of common severe acute toxicities.

Conclusions: Brachytherapy is a possible option in anal cancer radiotherapy to perform the boost to complete external beam radiotherapy (EBRT). Magnetic resonance can also have biological advantages compared to the US. Our results suggest that the multiparametric MR/CT-IABT for anal cancer is feasible and safe. This new approach paves the way to prospective comparison studies between MRI and ultrasound-guided brachytherapy (USBT) in anal canal cancer.

No MeSH data available.


Related in: MedlinePlus

Contouring with radiologist
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Figure 0001: Contouring with radiologist

Mentions: We programmed a pre-planning phase to obtain an optimal treatment. In fact, while ultrasound-guided brachytherapy (USBT) allows on-line evaluation, MRI still needs off-line conformal registration with CT-simulation. Patients underwent planning MRI study with an MRI-compatible dummy applicator [14]. Magnetic resonance imaging with contrast and diffusion weighted imaging (DWI) were performed to define the position of the scar or the residual disease. We acquired MR imaging data on 1.5-T unit (Horizon Advantage, GE Medical Systems, Milwaukee, WIS, USA). Nodular residual “tumor” tissues, intermediate or high tumor signal intensity (higher than muscle) were defined as residual tumor, on conventional T2 weighted-MRI sequences. The scar was defined as diffuse hypointense “fibrotic” thickening of the anal canal wall. On the DWI-MRI sequences (b factor = 1000 sec/mm2), the residual tumor was defined as a persistence of increased signal intensity on DWI in the previous tumor localization, using the normal rectal wall, outside the previous tumor area, as the internal reference. Three Regions of Interest (ROIs) were drawn on the dynamic T1-weighted spoiled gradient echo images section, taken from each section of the entire tumor, considering the corresponding T2-weighted axial images. ROI 1 involved the entire tumor area; ROI 2 involved the normal rectal wall adjacent to the tumor; ROI 3 only involved the high-contrast enhancement area within the tumor. ROI 3 was considered the residual tumor area. According to these data, the radiologist contoured the target based on the images (Figure 1).


MITHRA - multiparametric MR/CT image adapted brachytherapy (MR/CT-IABT) in anal canal cancer: a feasibility study.

Tagliaferri L, Manfrida S, Barbaro B, Colangione MM, Masiello V, Mattiucci GC, Placidi E, Autorino R, Gambacorta MA, Chiesa S, Mantini G, Kovács G, Valentini V - J Contemp Brachytherapy (2015)

Contouring with radiologist
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4663214&req=5

Figure 0001: Contouring with radiologist
Mentions: We programmed a pre-planning phase to obtain an optimal treatment. In fact, while ultrasound-guided brachytherapy (USBT) allows on-line evaluation, MRI still needs off-line conformal registration with CT-simulation. Patients underwent planning MRI study with an MRI-compatible dummy applicator [14]. Magnetic resonance imaging with contrast and diffusion weighted imaging (DWI) were performed to define the position of the scar or the residual disease. We acquired MR imaging data on 1.5-T unit (Horizon Advantage, GE Medical Systems, Milwaukee, WIS, USA). Nodular residual “tumor” tissues, intermediate or high tumor signal intensity (higher than muscle) were defined as residual tumor, on conventional T2 weighted-MRI sequences. The scar was defined as diffuse hypointense “fibrotic” thickening of the anal canal wall. On the DWI-MRI sequences (b factor = 1000 sec/mm2), the residual tumor was defined as a persistence of increased signal intensity on DWI in the previous tumor localization, using the normal rectal wall, outside the previous tumor area, as the internal reference. Three Regions of Interest (ROIs) were drawn on the dynamic T1-weighted spoiled gradient echo images section, taken from each section of the entire tumor, considering the corresponding T2-weighted axial images. ROI 1 involved the entire tumor area; ROI 2 involved the normal rectal wall adjacent to the tumor; ROI 3 only involved the high-contrast enhancement area within the tumor. ROI 3 was considered the residual tumor area. According to these data, the radiologist contoured the target based on the images (Figure 1).

Bottom Line: The dosimetric analysis resulted in a median of V200, V150, V100, V90, V85, respectively of 24.6%, 53.4%, 93.5%, 97.6%, and 98.7%.The median coverage index (CI) was 0.94, the median dose homogeneity index (DHI) was 0.43, the median dose non-uniformity ratio (DNR) resulted 0.56, the median overdose volume index (ODI) was 0.27.Magnetic resonance can also have biological advantages compared to the US.

View Article: PubMed Central - PubMed

Affiliation: Radiation Oncology Department, Gemelli-ART, Università Cattolica del Sacro Cuore, Rome, Italy.

ABSTRACT

Purpose: The aim of this study is to test a novel multiparametric imaging guided procedure for high-dose-rate brachytherapy in anal canal cancer, in order to evaluate the feasibility and safety.

Material and methods: For this analysis, we considered all consecutive patients who underwent magnetic resonance/computed tomography image adapted brachytherapy (MR/CT-IABT) treated from February 2012 to July 2014. To conduct this project, we formed a working group that established the procedure and identified the indicators and benchmarks to evaluate the feasibility and safety. We considered the procedure acceptable if 90% of the indicators were consistent with the benchmarks. Magnetic resonance imaging with contrast and diffusion weighted imaging were performed with an MRI-compatible dummy applicator in the anus to define the position of the clinical target volume disease and biological information. A pre-implantation treatment planning was created in order to get information on the optimal position of the needles. Afterwards, the patient underwent a simulation CT and the definite post-implantation treatment planning was created.

Results: We treated 11 patients (4 men and 7 women) with MR/CT-IABT and we performed a total of 13 procedures. The analysis of indicators for procedure evaluation showed that all indicators were in agreement with the benchmark. The dosimetric analysis resulted in a median of V200, V150, V100, V90, V85, respectively of 24.6%, 53.4%, 93.5%, 97.6%, and 98.7%. The median coverage index (CI) was 0.94, the median dose homogeneity index (DHI) was 0.43, the median dose non-uniformity ratio (DNR) resulted 0.56, the median overdose volume index (ODI) was 0.27. We observed no episodes of common severe acute toxicities.

Conclusions: Brachytherapy is a possible option in anal cancer radiotherapy to perform the boost to complete external beam radiotherapy (EBRT). Magnetic resonance can also have biological advantages compared to the US. Our results suggest that the multiparametric MR/CT-IABT for anal cancer is feasible and safe. This new approach paves the way to prospective comparison studies between MRI and ultrasound-guided brachytherapy (USBT) in anal canal cancer.

No MeSH data available.


Related in: MedlinePlus