Tissue dose estimation after extravasation of 177Lu-DOTATATE

Abstract Background Extravasation of radiopharmaceuticals used for vectorized internal radiotherapy can lead to severe tissue damage (van der Pol et al., Eur J Nucl Med Mol Imaging 44:1234–1243, 2017). Clinical management of these extravasations requires the preliminary estimation of the dose distribution in the extravasation area. Data are scarce regarding the dose estimation in the literature. This work presents a methodology for estimating the dose distribution after an extravasation occurred in September 2017, in the arm of a patient during a 7.4-GBq infusion of Lutathera ® (AAA). Methods A local quantification procedure initially developed for renal dosimetry was used. A calibration factor was determined and verified by phantom study. Extravasation volume of interest and its variation in time were determined using 4 whole body (WB) planar acquisitions performed at 2 h (T2h), 5 h (T5h), 20 h (T20h), and 26 h (T26h) after the beginning of the infusion and three SPECT/CT thoracic acquisitions at T5h, T20h, and T26h. For better estimation of initial extravasation volume, 3 volumes were defined on SPECT images using a 3D activity threshold. Cumulated activities and associated absorbed doses (D1, D2, D3) were calculated in the 3 volumes using the MIRD formalism. Results Volumes estimated using 3D threshold were V1 = 1000 mL, V2 =400 mL, and V3 =180 mL. Cumulated activities were evaluated using a monoexponential fit on activities calculated on SPECT images. Estimated local absorbed doses in V1, V2, and V3 were D1 = 2.3 Gy, D2 = 4.1 Gy, and D3 = 6.8 Gy. Evolution in time of local activity in the extravasation area was consistent with an effective local half-life (Teff) of 2.3 h. Conclusions Rapid local dose estimation was permitted thanks to knowledge of the calibration factor determined previous to accidental extravasation. Lutathera® lymphatic drainage was quick in the arm (Teff = 2.3h). Estimated doses were in the lower range of deterministic effects and far under soft tissue necrosis threshold. Thus, no surgical rinse was proposed. The patient did not show any clinical consequence of the extravasation.

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Tissue dose estimation after extravasation of 177Lu-DOTATATE

10.21203/rs.3.rs-57991/v1 ◽

2020 ◽

Author(s):

Perrine Tylski ◽

Géraldine Pina-Jomir ◽

Claire Bournaud-Salinas ◽

Patrice Jalade

Keyword(s):

Dose Distribution ◽

Lymphatic Drainage ◽

Calibration Factor ◽

Whole Body ◽

Clinical Consequence ◽

Dose Estimation ◽

Internal Radiotherapy ◽

Absorbed Doses ◽

Soft Tissue Necrosis ◽

Spect Images

Abstract Background. Extravasation of radiopharmaceuticals used for vectorized internal radiotherapy can lead to severe tissue damage (1). Clinical management of these extravasations requires the preliminary estimation of the dose distribution in the extravasation area. Data are scarce regarding the dose estimation in the literature. This work presents a methodology for estimating the dose distribution after an extravasation occurred in September 2017, in the arm of a patient during a 7.4 GBq infusion of Lutathera ® (AAA). Methods. A local quantification procedure initially developed for renal dosimetry was used. A calibration factor was determined and verified by phantom study. Extravasation volume of interest and its variation in time were determined using 4 whole body (WB) planar acquisitions performed at 2h (T2h), 5h (T5h), 20h (T20h) and 26h (T26h) after the beginning of the infusion and three SPECT/CT thoracic acquisitions at T5h, T20h and T26h. For better estimation of initial extravasation volume, 3 volumes were defined on SPECT images using a 3D activity threshold. Cumulated activities and associated absorbed doses (D1, D2, D3) were calculated in the 3 volumes using the MIRD formalism.Results. Volumes estimated using 3D threshold were V1= 1000 mL, V2=400 mL and V3=180 mL. Cumulated activities were evaluated using a mono exponential fit on activities calculated on SPECT images. Estimated local absorbed doses in V1, V2 and V3 were D1 = 2.8 Gy, D2 = 5.4 Gy and D3 = 7.8 Gy. Evolution in time of local activity in the extravasation area was consistent with an effective local period (Teff) of 3 hours.Conclusions. Rapid local doses estimation was permitted thank to knowledge of the calibration factor determined previous to accidental extravasation. Luthatera® lymphatic drainage was quick in the arm (Teff = 3h). Estimated doses were in the lower range of deterministic effects and far under soft tissue necrosis threshold. Thus no surgical rinse was proposed. The patient did not show any clinical consequence of theses extravasation.

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A Simple Method for the Evaluation of Internal Doses in Nuclear Medicine

Nuklearmedizin ◽

10.1055/s-0038-1624857 ◽

1974 ◽

Vol 13 (02) ◽

pp. 193-206

Author(s):

L. Conte ◽

L. Mombelli ◽

A. Vanoli

Keyword(s):

Nuclear Medicine ◽

Close Agreement ◽

Whole Body ◽

Simple Method ◽

Rapid Estimation ◽

Absorbed Doses ◽

The Mean ◽

The Individual ◽

Estimation Of Risk

SummaryWe have put forward a method to be used in the field of nuclear medicine, for calculating internally absorbed doses in patients. The simplicity and flexibility of this method allow one to make a rapid estimation of risk both to the individual and to the population. In order to calculate the absorbed doses we based our procedure on the concept of the mean absorbed fraction, taking into account anatomical and functional variability which is highly important in the calculation of internal doses in children. With this aim in mind we prepared tables which take into consideration anatomical differences and which permit the calculation of the mean absorbed doses in the whole body, in the organs accumulating radioactivity, in the gonads and in the marrow; all this for those radionuclides most widely used in nuclear medicine. By comparing our results with dose obtained from the use of M.I.R.D.'s method it can be seen that when the errors inherent in these types of calculation are taken into account, the results of both methods are in close agreement.

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Is nuclear medicine really safe?

Brazilian Archives of Biology and Technology ◽

10.1590/s1516-89132002000500016 ◽

2002 ◽

Vol 45 (spe) ◽

pp. 115-118

Author(s):

Nicole Colas-Linhart

Keyword(s):

Nuclear Medicine ◽

Human Serum Albumin ◽

Radiation Dose ◽

Serum Albumin ◽

Human Serum ◽

Absorbed Dose ◽

Cellular Level ◽

Whole Body ◽

Absorbed Doses ◽

Standard Models

In nuclear medicine, radiation absorbed dose estimates calculated by standard models at the whole body or organ are very low. At cellular level, however, the heterogeneity of radionuclide distributions of radiation dose patterns may be significant. We present here absorbed doses at cellular level and evaluate their possible impact on the usually assumed risk/benefit relationships in nuclear medicine studies. The absorbed dose values calculated are surprisingly high, and are difficult to interpret. In the present study, we show calculated doses at the cellular level and discuss possible biological consequences, for two radiopharmaceuticals labelled with technetium-99m: human serum albumin microspheres used for pulmonary scintigrapies and HMPAO used to labelled leukocytes.

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Deep learning based automatic segmentation of metastasis hotspots in thorax bone SPECT images

PLoS ONE ◽

10.1371/journal.pone.0243253 ◽

2020 ◽

Vol 15 (12) ◽

pp. e0243253

Author(s):

Qiang Lin ◽

Mingyang Luo ◽

Ruiting Gao ◽

Tongtong Li ◽

Zhengxing Man ◽

...

Keyword(s):

Deep Learning ◽

Fine Tuning ◽

Disease Stage ◽

Whole Body ◽

Learning Technology ◽

Automatic Assessment ◽

Original Dataset ◽

Bone Spect ◽

Segmentation Models ◽

Spect Images

SPECT imaging has been identified as an effective medical modality for diagnosis, treatment, evaluation and prevention of a range of serious diseases and medical conditions. Bone SPECT scan has the potential to provide more accurate assessment of disease stage and severity. Segmenting hotspot in bone SPECT images plays a crucial role to calculate metrics like tumor uptake and metabolic tumor burden. Deep learning techniques especially the convolutional neural networks have been widely exploited for reliable segmentation of hotspots or lesions, organs and tissues in the traditional structural medical images (i.e., CT and MRI) due to their ability of automatically learning the features from images in an optimal way. In order to segment hotspots in bone SPECT images for automatic assessment of metastasis, in this work, we develop several deep learning based segmentation models. Specifically, each original whole-body bone SPECT image is processed to extract the thorax area, followed by image mirror, translation and rotation operations, which augments the original dataset. We then build segmentation models based on two commonly-used famous deep networks including U-Net and Mask R-CNN by fine-tuning their structures. Experimental evaluation conducted on a group of real-world bone SEPCT images reveals that the built segmentation models are workable on identifying and segmenting hotspots of metastasis in bone SEPCT images, achieving a value of 0.9920, 0.7721, 0.6788 and 0.6103 for PA (accuracy), CPA (precision), Rec (recall) and IoU, respectively. Finally, we conclude that the deep learning technology have the huge potential to identify and segment hotspots in bone SPECT images.

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Is it necessary to reduce the radioiodine dose in patients with thyroid cancer and renal failure?

Arquivos Brasileiros de Endocrinologia & Metabologia ◽

10.1590/s0004-27302010000400011 ◽

2010 ◽

Vol 54 (4) ◽

pp. 413-418 ◽

Cited By ~ 4

Author(s):

José Willegaignon ◽

Verena Pinto Brito Ribeiro ◽

Marcelo Sapienza ◽

Carla Ono ◽

Tomoco Watanabe ◽

...

Keyword(s):

Thyroid Cancer ◽

Dose Adjustment ◽

Absorbed Dose ◽

Whole Body ◽

Half Time ◽

Dialysis Therapy ◽

Absorbed Doses ◽

131I Activity ◽

Dosimetric Data ◽

Higher Doses

The objective of this study were to obtain dosimetric data from a patient with thyroid cancer simultaneously undergoing peritoneal dialysis therapy, so as to determine the appropriate amount of 131I activity to be applied therapeutically. Percentages of radioiodine in the blood and the whole-body were evaluated, and radiation absorbed doses were calculated according to OLINDA/EXM software. Whole-body 131I effective half-time was 45.5 hours, being four times longer than for patients without any renal dysfunction. Bone-marrow absorbed dose was 0.074 mGy/MBq, with ablative procedure maintenance at 3.7 GBq, as the reported absorbed dose was insufficiently restrictive to change the usual amount of radioiodine activity administered for ablation. It was concluded that radioiodine therapeutic-dose adjustment, based on individual patient dosimetry, is an important way of controlling therapy. It also permits the safe and potential delivery of higher doses of radiation to tumors and undesirable tissues, with a minimum of malignant effects on healthy tissues.

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Inhomogeneity of Dose Distribution in Animals Subjected to Whole-Body Irradiation with 250-Kvp X-Rays

Radiation Research ◽

10.2307/3571593 ◽

1964 ◽

Vol 21 (3) ◽

pp. 462 ◽

Cited By ~ 2

Author(s):

Stanley J. Malsky ◽

Charles G. Amato ◽

Victor P. Bond ◽

James S. Robertson ◽

Bernard Roswit

Keyword(s):

Dose Distribution ◽

Whole Body ◽

X Rays

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An analysis of the dose distribution in whole-body superficial electron beam therapy

Physics in Medicine and Biology ◽

10.1088/0031-9155/18/4/029 ◽

1973 ◽

Vol 18 (4) ◽

pp. 590-590

Author(s):

V Krishnaswamy

Keyword(s):

Electron Beam ◽

Dose Distribution ◽

Whole Body ◽

Electron Beam Therapy

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Fluid Shifts Induced by Physical Therapy in Lower Limb Lymphedema Patients

Journal of Clinical Medicine ◽

10.3390/jcm9113678 ◽

2020 ◽

Vol 9 (11) ◽

pp. 3678 ◽

Cited By ~ 1

Author(s):

Bianca Brix ◽

Gert Apich ◽

Andreas Roessler ◽

Christian Ure ◽

Karin Schmid-Zalaudek ◽

...

Keyword(s):

Physical Therapy ◽

Plasma Volume ◽

Bioelectrical Impedance ◽

Impedance Analysis ◽

Lymphatic Drainage ◽

Whole Body ◽

Fluid Composition ◽

Manual Lymphatic Drainage ◽

Complete Decongestive Therapy ◽

Fluid Shifts

Complete decongestive therapy (CDT), a physical therapy including manual lymphatic drainage (MLD) and compression bandaging, is aimed at mobilizing fluid and reducing limb volume in lymphedema patients. Details of fluid shifts occurring in response to CDT are currently not well studied. Therefore, we investigated fluid shifts before, during and after CDT. Thirteen patients (3 males and 10 females, aged 57 ± 8.0 years, 167.2 ± 8.3 cm height, 91.0 ± 23.4 kg weight) diagnosed with stage II leg lymphedema participated. Leg volume, limb and whole-body fluid composition (total body water (limbTBW/%TBW), extracellular (limbECF/%ECF) and intracellular (limbICF/%ICF fluid), as well as ECF/ICF and limbECF/limbICF ratios were determined using perometry and bioelectrical impedance spectroscopy. Plasma volume, proteins, osmolality, oncotic pressure and electrolytes were assessed. Leg volume (p < 0.001), limbECF (p = 0.041), limbICF (p = 0.005) and limbECF/limbICF decreased over CDT. Total leg volume and limbTBW were correlated (r = 0.635). %TBW (p = 0.001) and %ECF (p = 0.007) decreased over time. The maximum effects were seen within one week of CDT. LimbICF (p = 0.017), %TBW (p = 0.009) and %ICF (p = 0.003) increased post-MLD, whereas ECF/ICF decreased due to MLD. Plasma volume increased by 1.5% post-MLD, as well as albumin and the albumin-to-globulin ratio (p = 0.005 and p = 0.049, respectively). Our results indicate that physical therapy leads to fluid shifts in lymphedema patients, with the greatest effects occurring within one week of therapy. Fluid shifts due to physical therapy were also reflected in increased plasma volume and plasma protein concentrations. Perometry, in contrast to bioelectrical impedance analysis, does not seem to be sensitive enough to detect small fluid changes caused by manual lymphatic drainage.

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