S-values for bone marrow dosimetry in preclinical radiopharmaceutical studies with rodents
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
Abstract Background Development of novel radiopharmaceuticals involves dosimetry calculations to validate safety and aid with selection of those that should be translated into the clinical environment. Dosimetry is critical for limiting radiation damage to organs at risk. The bone marrow is a limiting organ in radiopharmaceutical therapies (RPTs) for metastatic prostate cancer, for example, but there is room for improvement of bone marrow dosimetry in preclinical studies. Bone marrow S -values for Lutetium-177 ( 177 Lu) in rodents have been published but they have not included tumor xenografts inoculated in the shoulder, which is how radiopharmaceuticals are often tested. Here, we aim at performing Monte Carlo simulations on digital mice phantoms including tumor xenografts, and to determine new bone marrow S-values that can potentially improve our understanding of the effect of RPTs in blood cells. Methods S -values for 177 Lu were simulated in the 4D Mouse Whole Body (MOBY) phantom, a hybrid voxel-based mouse model, using GATE v9.3 MC toolkit. Two phantoms of different resolutions and equal mass were created. 3D dose distributions were simulated and the corresponding organ to organ S -values were calculated. The resulting S -values were validated against reference values from OLINDA v2.2.3. Later, tumours of varying sizes were placed in the left shoulder and tumour-to-organ S -values were calculated from MC simulations with a 177 Lu source placed uniformly in these tumours. Results The phantoms simulated here differed from the OLINDA phantom in both organ mass and geometry for many tissues; S -value deviations from OLINDA were correlated with these differences, as reported in previous studies, and ranged from 2% for the kidney self-dose in the higher resolution (HR) phantom to 477% for S (skeleton←spleen) in the lower resolution (LR) phantom. S -values were simulated for the bone marrow in both phantoms; cross-dose values were greatest from the skeleton, brain, and lungs, while cross-doses from the simulated tumours were approximately constant at 3 × 10 –15 Gy Bq −1 s −1 across all tumour sizes. The components of the skeleton receiving the greatest tumour cross-doses from the tumours were the spine, skull and marrow. S -values targeting the bone marrow were compared to similar values from a previous study, whose phantom differed in tissue composition—discrepancies ranged from 6% for S(BM←kidneys) at LR to 87% for S (BM←BM) at HR. In general, relative uncertainty in dose and dose factor deposited from one tissue to another was inversely proportional to the corresponding S -value magnitude, and lower uncertainties were yielded from simulations in the LR, large-voxel phantom. Conclusion Using the MOBY digital mouse phantom, we simulated bone marrow S -values for 177 Lu. We hope these values help researchers perform preclinical dosimetry in rodents including bone marrow and tumor xenografts and facilitate the translation of novel radiopharmaceuticals.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it