Poster — Wed Eve—04: Dosimetric Effects of Seed Delivery Error and Ultrasound Probe Deformation During Prostate Brachytherapy
Bibliographic record
Abstract
Permanent seed prostate brachytherapy post plan dosimetry often shows significant deterioration from the treatment plan, commonly attributed to a large number of effects and implant uncertainties. The purpose of this study is to determine the amount of probe deformation and the dosimetric effects of seed delivery errors for typical clinical implants. A C‐arm was used to take variable angle images of clinical implants immediately after the last needle was delivered, with the patient and ultrasound remaining in the treatment position, and again after the ultrasound probe had been removed from the patients. Three dimensional seed coordinates were reconstructed for each of the variable angle image sets. Dosimetry comparison between the treatment plan D90 (mean 196 Gy) and the planning contours with seed coordinates immediately post‐implant showed a mean reduction of 48 Gy (range 44 Gy to 64 Gy) attributable to delivery accuracy. A rigid body registration was performed between seed coordinates to remove overall gland motion and residual seed coordinates were compared to observe seed motion due to probe deformation. The residual seed motion showed non‐random deformational patterns, but was small in magnitude (mean 1.1 mm, range 0.2 mm – 4.4 mm) and showed less impact on D90, although values were dependent on contour volume. These results demonstrate that much of the reduced dosimetry observed at post‐plan occurs in the operating room where technical advances or changes in the implant procedure may improve results.
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.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.003 |
| 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) | 0.003 | 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 itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".