The Effect of Absorbed Dose to Organs at Risk Following Craniospinal Irradiation Using Different Radiotherapy Techniques

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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Postoperative Radiation Therapy in Mammary Carcinoma Stage II: Target volume, organs at risk, absorbed dose, time-dose schedule, and dose to organs at risk in a prospective investigation

Acta Radiologica Oncology Radiation Physics Biology ◽

10.3109/02841867909128213 ◽

1979 ◽

Vol 18 (4) ◽

pp. 273-281 ◽

Cited By ~ 8

Author(s):

Å. Arwidi ◽

K. Aspegren ◽

N. E. Augustsson ◽

Lo. Hafström ◽

A. Norgren ◽

...

Keyword(s):

At Risk ◽

Radiation Therapy ◽

Organs At Risk ◽

Absorbed Dose ◽

Dose Schedule ◽

Target Volume ◽

Postoperative Radiation ◽

Postoperative Radiation Therapy ◽

Dose Time ◽

Prospective Investigation

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Proton therapy in craniospinal irradiation: a systematic review

Journal of Radiotherapy in Practice ◽

10.1017/s146039691500045x ◽

2015 ◽

Vol 15 (2) ◽

pp. 196-202

Author(s):

Adam I. Husak ◽

Pete Bridge

Keyword(s):

Systematic Review ◽

At Risk ◽

Radiation Therapy ◽

Head And Neck ◽

Proton Therapy ◽

Critical Appraisal ◽

Organs At Risk ◽

Craniospinal Irradiation ◽

Cochrane Library ◽

Increased Risk

AbstractAimCraniospinal irradiation is a technique indicated when a patient has a malignancy that has either disseminated, or is at risk of disseminating, throughout the subarachnoid space. While the craniospinal axis is treatable with conventional radiotherapy, the high doses to organs at risk carry an increased risk of acute and late side effects. Proton craniospinal irradiation is an expensive technique that shows great theoretical promise arising from reduced exit doses. The purpose of this systematic review is to determine the potential role of proton therapy as a standard modality for craniospinal irradiation.Materials and methodsA literature review was performed to determine the efficacy and cost of proton craniospinal irradiation. The Cochrane Library and the Inspec, Medline (via Pubmed) and Scopus databases were searched. After exclusion criteria were applied, the remaining papers were systematically appraised utilising the Scottish Intercollegiate Guidelines Network critical appraisal checklists.ResultsA total of 14 articles remained following the application of the screening and critical appraisal processes. In total, five of the articles concluded that the risk of secondary malignancy was lower with proton therapy, while ten of the articles included data showing that toxicity rates and organs at risk doses were lower with proton therapy. Doses to most thoracic and abdominal organs at risk analysed in the literature were reduced when proton therapy was used, with the sole exception of the oesophagus, the dose to which depended on whether or not the entire vertebral body was treated. Proton therapy also delivered optimal doses to organs at risk in the head and neck compared with conformal radiation therapy. However, in one study that compared tomotherapy to proton therapy, tomotherapy outperformed proton therapy by delivering lower doses to organs at risk in the head and neck, as well as the kidneys. The two cost-effectiveness studies did not indicate proton therapy as an optimal modality for all treatment sites; however, one of the studies found that for medulloblastoma, protons were more cost effective than conventional radiation therapy.FindingsProton therapy is a superior treatment option for craniospinal irradiation. The reduction in risk of toxicity and radiocarcinogenesis offered by proton craniospinal irradiation appear to outweigh the increased costs.

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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/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]Lu-DOTA-TATE: comparison with Dosimetry Toolkit® and OLINDA/EXM® V1.0

EJNMMI Research ◽

10.1186/s13550-020-00737-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Lore Santoro ◽

L. Pitalot ◽

D. Trauchessec ◽

E. Mora-Ramirez ◽

P. O. 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 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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Dosimetric Analysis of Three Different Radiotherapy Techniques in Patients with Breast Cancer and Their Impact on Organs at Risk (OAR)

International Journal of Medical Physics Clinical Engineering and Radiation Oncology ◽

10.4236/ijmpcero.2018.72011 ◽

2018 ◽

Vol 07 (02) ◽

pp. 131-140

Author(s):

Vikas Jagtap ◽

Dimpal Saikia ◽

Shashi Bhushan Sharma ◽

Shayori Bhattacharjee ◽

Moirangthem Nara Singh ◽

...

Keyword(s):

Breast Cancer ◽

At Risk ◽

Organs At Risk ◽

Radiotherapy Techniques ◽

Dosimetric Analysis

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[68Ga]Ga-PSMA-11 PET imaging as a predictor for absorbed doses in organs at risk and small lesions in [177Lu]Lu-PSMA-617 treatment

European Journal of Nuclear Medicine and Molecular Imaging ◽

10.1007/s00259-021-05538-2 ◽

2021 ◽

Author(s):

Steffie M. B. Peters ◽

Regina Hofferber ◽

Bastiaan M. Privé ◽

Maarten de Bakker ◽

Martin Gotthardt ◽

...

Keyword(s):

At Risk ◽

Patient Selection ◽

Organs At Risk ◽

Absorbed Dose ◽

Target Volume ◽

Tracer Uptake ◽

Parotid Glands ◽

Dose Ratio ◽

Psma Pet ◽

Pet Ct

Abstract Introduction Patient eligibility for [177Lu]Lu-PSMA therapy remains a challenge, with only 40–60% response rate when patient selection is done based on the lesion uptake (SUV) on [68Ga]Ga-PSMA-PET/CT. Prediction of absorbed dose based on this pre-treatment scan could improve patient selection and help to individualize treatment by maximizing the absorbed dose to target lesions while adhering to the threshold doses for the organs at risk (kidneys, salivary glands, and liver). Methods Ten patients with low-volume hormone-sensitive prostate cancer received a pre-therapeutic [68Ga]Ga-PSMA-11 PET/CT, followed by 3 GBq [177Lu]Lu-PSMA-617 therapy. Intra-therapeutically, SPECT/CT was acquired at 1, 24, 48, 72, and 168 h. Absorbed dose in organs and lesions (n = 22) was determined according to the MIRD scheme. Absorbed dose prediction based on [68Ga]Ga-PSMA-PET/CT was performed using tracer uptake at 1 h post-injection and the mean tissue effective half-life on SPECT. Predicted PET/actual SPECT absorbed dose ratios were determined for each target volume. Results PET/SPECT absorbed dose ratio was 1.01 ± 0.21, 1.10 ± 0.15, 1.20 ± 0.34, and 1.11 ± 0.29 for kidneys (using a 2.2 scaling factor), liver, submandibular, and parotid glands, respectively. While a large inter-patient variation in lesion kinetics was observed, PET/SPECT absorbed dose ratio was 1.3 ± 0.7 (range: 0.4–2.7, correlation coefficient r = 0.69, p < 0.01). Conclusion A single time point [68Ga]Ga-PSMA-PET scan can be used to predict the absorbed dose of [177Lu]Lu-PSMA therapy to organs, and (to a limited extent) to lesions. This strategy facilitates in treatment management and could increase the personalization of [177Lu]Lu-PSMA therapy.

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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-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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