Clinical implementation of PLANET® Dose for dosimetric assessment after [177Lu]Lu-DOTA-TATE: comparison with Dosimetry Toolkit® and OLINDA/EXM® V1.0

Abstract Background The aim of this study was to compare a commercial dosimetry workstation (PLANET® Dose) and the dosimetry approach (GE Dosimetry Toolkit® and OLINDA/EXM® V1.0) currently used in our department for quantification of the absorbed dose (AD) to organs at risk after peptide receptor radionuclide therapy with [177Lu]Lu-DOTA-TATE. Methods An evaluation on phantom was performed to determine the SPECT calibration factor variations over time and to compare the Time Integrated Activity Coefficients (TIACs) obtained with the two approaches. Then, dosimetry was carried out with the two tools in 21 patients with neuroendocrine tumours after the first and second injection of 7.2 ± 0.2 GBq of [177Lu]Lu-DOTA-TATE (40 dosimetry analyses with each software). SPECT/CT images were acquired at 4 h, 24 h, 72 h and 192 h post-injection and were reconstructed using the Xeleris software (General Electric). The liver, spleen and kidneys masses and TIACs were determined using Dosimetry Toolkit® (DTK) and PLANET® Dose. The ADs were calculated using OLINDA/EXM® V1.0 and the Local Deposition Method (LDM) or Dose voxel-Kernel convolution (DK) on PLANET® Dose. Results With the phantom, the 3D calibration factors showed a slight variation (0.8% and 3.3%) over time, and TIACs of 225.19 h and 217.52 h were obtained with DTK and PLANET® Dose, respectively. In patients, the root mean square deviation value was 8.9% for the organ masses, 8.1% for the TIACs, and 9.1% and 7.8% for the ADs calculated with LDM and DK, respectively. The Lin’s concordance correlation coefficient was 0.99 and the Bland–Altman plot analysis estimated that the AD value difference between methods ranged from − 0.75 to 0.49 Gy, from − 0.20 to 0.64 Gy, and from − 0.43 to 1.03 Gy for 95% of the 40 liver, kidneys and spleen dosimetry analyses. The dosimetry method had a minor influence on AD differences compared with the image registration and organ segmentation steps. Conclusions The ADs to organs at risk obtained with the new workstation PLANET® Dose are concordant with those calculated with the currently used software and in agreement with the literature. These results validate the use of PLANET® Dose in clinical routine for patient dosimetry after targeted radiotherapy with [177Lu]Lu-DOTA-TATE.

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Clinical implementation of PLANET®Dose for dosimetric assessment after [177Lu]Lu-DOTA-TATE: comparison with Dosimetry Toolkit® and OLINDA/EXM® V1.0

10.21203/rs.3.rs-36998/v4 ◽

2020 ◽

Author(s):

Lore Santoro ◽

Laurine Pitalot ◽

Dorian Trauchessec ◽

Erick Mora-Ramirez ◽

Pierre-Olivier Kotzki ◽

...

Keyword(s):

At Risk ◽

Organs At Risk ◽

Absorbed Dose ◽

Peptide Receptor Radionuclide Therapy ◽

Slight Variation ◽

Clinical Implementation ◽

Plot Analysis ◽

A Minor ◽

Local Deposition ◽

Over Time

Abstract Background: The aim of this study was to compare a commercial dosimetry workstation (PLANET®Dose) and the dosimetry approach (GE Dosimetry Toolkit® and OLINDA/EXM® V1.0) currently used in our department for quantification of the absorbed dose (AD) to organs at risk after peptide receptor radionuclide therapy with [177Lu]Lu-DOTA-TATE.Methods: An evaluation on phantom was performed to determine the SPECT calibration factor variations over time and to compare the Time Integrated Activity Coefficients (TIACs) obtained with the two approaches. Then, dosimetry was carried out with the two tools in 21 patients with neuroendocrine tumours after the first and second injection of 7.2 ± 0.2 GBq of [177Lu]Lu-DOTA-TATE (40 dosimetry analyses with each software). SPECT/CT images were acquired at 4h, 24h, 72h and 192h post-injection and were reconstructed using the Xeleris software (General Electric). The liver, spleen and kidneys masses and TIACs were determined using Dosimetry Toolkit® (DTK) and PLANET®Dose. The ADs were calculated using OLINDA/EXM® V1.0 and the Local Deposition Method (LDM) or Dose voxel-Kernel convolution (DK) on PLANET®Dose.Results: With the phantom, the 3D calibration factors showed a slight variation (0.8% and 3.3%) over time, and TIACs of 225.19h and 217.52h were obtained with DTK and PLANETâDose, respectively. In patients, the root mean square deviation value was 8.9% for the organ masses, 8.1% for the TIACs, and 9.1% and 7.8% for the ADs calculated with LDM and DK, respectively. The Lin’s concordance correlation coefficient was 0.99 and the Bland-Altman plot analysis estimated that the AD value difference between methods ranged from -0.75 Gy to 0.49 Gy, from -0.20 Gy to 0.64 Gy, and from -0.43 to 1.03 Gy for 95% of the 40 liver, kidneys and spleen dosimetry analyses. The dosimetry method had a minor influence on AD differences compared with the image registration and organ segmentation steps.Conclusions: The ADs to organs at risk obtained with the new workstation PLANET®Dose are concordant with those calculated with the currently used software and in agreement with the literature. These results validate the use of PLANET®Dose in clinical routine for patient dosimetry after targeted radiotherapy with [177Lu]Lu-DOTA-TATE.

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Clinical implementation of PLANET®Dose for dosimetric assessment after [177Lu]Lu-DOTA-TATE: comparison with Dosimetry Toolkit® and OLINDA/EXM® V1.0

10.21203/rs.3.rs-36998/v3 ◽

2020 ◽

Author(s):

Lore Santoro ◽

Laurine Pitalot ◽

Dorian Trauchessec ◽

Erick Mora-Ramirez ◽

Pierre-Olivier Kotzki ◽

...

Keyword(s):

At Risk ◽

Organs At Risk ◽

Absorbed Dose ◽

Peptide Receptor Radionuclide Therapy ◽

Slight Variation ◽

Clinical Implementation ◽

Plot Analysis ◽

A Minor ◽

Local Deposition ◽

Over Time

Abstract Background: The aim of this study was to compare a commercial dosimetry workstation (PLANET®Dose) and the dosimetry approach (GE Dosimetry Toolkit® and OLINDA/EXM® V1.0) currently used in our department for quantification of the absorbed dose (AD) to organs at risk after peptide receptor radionuclide therapy with [177Lu]Lu-DOTA-TATE.Methods: An evaluation on phantom was performed to determine the SPECT calibration factor variations over time and to compare the Time Integrated Activity Coefficients (TIACs) obtained with the two approaches. Then, dosimetry was carried out with the two tools in 21 patients with neuroendocrine tumours after the first and second injection of 7.2 ± 0.2 GBq of [177Lu]Lu-DOTA-TATE (40 dosimetry analyses with each software). SPECT/CT images were acquired at 4h, 24h, 72h and 192h post-injection and were reconstructed using the Xeleris software (General Electric). The liver, spleen and kidneys masses and TIACs were calculated using Dosimetry Toolkit® (DTK) and PLANET®Dose. The ADs were calculated using OLINDA/EXM® V1.0 and the Local Deposition Method (LDM) or Dose voxel-Kernel convolution (DK) on PLANET®Dose.Results: With the phantom, the 3D calibration factors showed a slight variation (0.8% and 3.3%) over time, and TIACs of 225.19h and 217.52h were obtained with DTK and PLANET®Dose, respectively. In patients, the root mean square deviation value was 8.9% for the organ masses, 8.1% for the TIACs, and 9.1 and 7.8% for the ADs calculated with LDM and DK, respectively. The Lin’s concordance correlation coefficient was 0.99 and the Bland-Altman plot analysis estimated that the AD value difference between methods ranged from -0.75 Gy to 0.49 Gy, from -0.20 Gy to 0.64 Gy, and from -0.43 to 1.03 Gy for 95% of the 40 liver, kidneys and spleen dosimetry analyses. The dosimetry method had a minor influence on AD differences compared with the image registration and organ segmentation steps. Conclusions: The ADs to organs at risk obtained with the new workstation PLANET®Dose are concordant with those calculated with the currently used software and in agreement with the literature. These results validate the use of PLANET®Dose in clinical routine for patient dosimetry after targeted radiotherapy with [177Lu]Lu-DOTA-TATE.

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Clinical implementation of PLANET®Dose for dosimetric assessment after [177Lu]Lu-DOTA-TATE : comparison with Dosimetry Toolkit® and OLINDA/EXM® V1.0

10.21203/rs.3.rs-36998/v2 ◽

2020 ◽

Author(s):

Lore Santoro ◽

Laurine Pitalot ◽

Dorian Trauchessec ◽

Erick Mora-Ramirez ◽

Pierre-Olivier Kotzki ◽

...

Keyword(s):

At Risk ◽

Organs At Risk ◽

Absorbed Dose ◽

Peptide Receptor Radionuclide Therapy ◽

Slight Variation ◽

Clinical Implementation ◽

Absorbed Doses ◽

Plot Analysis ◽

The Difference ◽

Over Time

Abstract Background: The aim of this study was to compare a commercial dosimetry workstation (PLANET®Dose) and the dosimetry approach (GE Dosimetry Toolkit® and OLINDA/EXM® V1.0) currently used in our department for quantification of the absorbed dose in organs at risk after peptide receptor radionuclide therapy with [177Lu]Lu-DOTA-TATE. Methods: An evaluation on phantom was performed to determine the SPECT calibration factor variations over time and to compare the Time Integrated Activity Coefficients (TIACs) and absorbed doses obtained with the two tools. Then, the two tools were used for dosimetry evaluation in 21 patients with neuroendocrine tumours after the first and second injection of 7.2 ± 0.2 GBq of [177Lu]Lu-DOTA-TATE (40 dosimetry analyses with each software). SPECT/CT images were acquired at 4h, 24h, 72h and 192h after [177Lu]Lu-DOTA-TATE injection and were reconstructed using the Xeleris software (General Electric). The liver, spleen and kidney masses, TIACs and absorbed doses were calculated using i) GE Dosimetry Toolkit® (DTK) and OLINDA/EXM® V1.0 and ii) the Local Deposition Method (LDM) or Dose voxel-Kernel convolution (DK) on PLANET®Dose. Results: With the phantom, the 3D calibration factors showed a slight variation (0.8% and 3.3%) over time and TIACs of 225.19h and 217.52h were obtained with DTK and PLANET®Dose, respectively. In patients, the root mean square deviation value was 8.9% for the organ masses, 8.1% for the TIACs, and 9.1 and 7.8% for the absorbed doses with LDM and DK, respectively. The Lin’s concordance correlation coefficient was 0.99 and the Bland-Altman plot analysis estimated that the difference of absorbed dose values between methods ranged from -0.75 Gy to 0.49 Gy, from -0.20 Gy to 0.64 Gy and from -0.43 to 1.03 Gy for approximately 95% of the 40 liver, kidneys and spleen dosimetry analyses. A difference of 2.2% was obtained between the absorbed doses to organs at risk calculated with LDM and DK. Conclusions: The absorbed doses to organs at risk obtained with the new workstation are concordant with those calculated with the currently used software and in agreement with the literature. These results validate the use of PLANET®Dose in clinical routine for patient dosimetry after targeted radiotherapy with [177Lu]Lu-DOTA-TATE.

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Clinical Implementation of PLANET®Dose for Dosimetric Assessment after 177Lu-DOTATATE: Comparison with Dosimetry Toolkit® and OLINDA/EXM® V1.0

10.21203/rs.3.rs-36998/v1 ◽

2020 ◽

Author(s):

Lore Santoro ◽

Laurine Pitalot ◽

Dorian Trauchessec ◽

Erick Mora-Ramirez ◽

Pierre-Olivier Kotzki ◽

...

Keyword(s):

At Risk ◽

Organs At Risk ◽

Absorbed Dose ◽

Peptide Receptor Radionuclide Therapy ◽

Slight Variation ◽

Clinical Implementation ◽

Absorbed Doses ◽

Relative Standard ◽

The Difference ◽

Over Time

Abstract Background: Recently, commercial software tools have become available for dosimetry evaluations in clinical settings. The aim of this study was to compare a commercial dosimetry workstation (PLANETâDose) and the dosimetry approach (GE Dosimetry Toolkit® and OLINDA/EXM® V1.0) currently used in our department for quantification of the absorbed dose in organs at risk after peptide receptor radionuclide therapy with 177Lu-DOTATATE.Methods: First, an evaluation on phantom, with data acquisition at 5 time points, was performed to determine the SPECT calibration factor variations over time and to compare the Time Integrated Activity Coefficients (TIACs) and absorbed doses obtained with the two tools. Then, the two tools were used for dosimetry evaluation in 21 patients with neuroendocrine tumours after the first and second injection of 7.2 ± 0.2 GBq of 177Lu-DOTATATE (40 dosimetry analyses with each software). SPECT/CT images were acquired at 4h, 24h, 72h and 192h after 177Lu-DOTATATE injection and were reconstructed using the Xeleris software (General Electric). The liver, spleen and kidney masses, TIACs and absorbed doses were calculated using i) GE Dosimetry Toolkit® (DTK) and OLINDA/EXM® V1.0 and ii) the Local Deposition Method (LDM) or Dose voxel-Kernel convolution (DK) on PLANETâDose. Results: With the phantom, the 3D calibration factors showed a slight variation (0.8% and 3.3%) over time and TIACs of 225.19h and 217.52h were obtained with DTK and PLANETâDose, respectively. In patients, the mean of the relative standard deviations was -1% for the organ masses, 5.6%, for the TIACs, and 4.4% for the absorbed doses. The Lin’s concordance correlation coefficient was 0.99 and the Bland-Altman plot analysis estimated that the difference of absorbed dose values between methods ranged from -0.58 Gy to 0.84 Gy for approximately 95% of the 40 dosimetry analyses. A difference of 2.2% was obtained between the absorbed doses to organs at risk calculated with LDM and DK (PLANETâDose). Conclusions: The absorbed doses to organs at risk obtained with the new workstation are concordant with those calculated with the currently used software and in agreement with the literature. These results validate the use of PLANETâDose in clinical routine for patient dosimetry after targeted radiotherapy with 177Lu-DOTATATE.

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Use of a Head-Tilting Baseplate During Tomotherapy to Shorten the Irradiation Time and Protect the Hippocampus and Lens in Hippocampal Sparing-Whole Brain Radiotherapy

Technology in Cancer Research & Treatment ◽

10.1177/1533033820986824 ◽

2021 ◽

Vol 20 ◽

pp. 153303382098682

Author(s):

Kosei Miura ◽

Hiromasa Kurosaki ◽

Nobuko Utsumi ◽

Hideyuki Sakurai

Keyword(s):

At Risk ◽

Planning Target Volume ◽

Irradiation Time ◽

Organs At Risk ◽

Absorbed Dose ◽

Whole Brain Radiotherapy ◽

Target Volume ◽

Whole Brain ◽

Brain Radiotherapy ◽

Hippocampal Sparing

Purpose: The aim of this study is to comparatively examine the possibility of reducing the exposure dose to organs at risk, such as the hippocampus and lens, and improving the dose distribution of the planned target volume with and without the use of a head-tilting base plate in hippocampal-sparing whole-brain radiotherapy using tomotherapy. Methods: Five paired images of planned head computed tomography without and with tilt were analyzed. The hippocampus and planning target volume were contoured according to the RTOG 0933 contouring atlas protocol. The hippocampal zone to be avoided was delineated using a 5-mm margin. The prescribed radiation dose was 30 Gy in 10 fractions. The absorbed dose to planning target volume dose, absorbed dose to the organ at risk, and irradiation time were evaluated. The paired t-test was used to analyze the differences between hippocampal-sparing whole-brain radiotherapy with head tilts and without head tilts. Results: Hippocampal-sparing whole-brain radiotherapy with tilt was not superior in planning target volume doses using the homogeneity index than that without tilt; however, it showed better values, and for Dmean and D2%, the values were closer to 30 Gy. Regarding the hippocampus, dose reduction with tilt was significantly greater at Dmax, Dmean, and Dmin, whereas regarding the lens, it was significantly greater at Dmax and Dmin. The irradiation time was also predominantly shorter. Conclusion: In our study, a tilted hippocampal-sparing whole-brain radiotherapy reduced the irradiation time by >10%. Therefore, our study indicated that hippocampal-sparing whole-brain radiotherapy with tomotherapy should be performed with a tilt. The head-tilting technique might be useful during hippocampal-sparing whole-brain radiotherapy. This method could decrease the radiation exposure time, while sparing healthy organs, including the hippocampus and lens.

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