221: Radiation Dose Mapping of the Stomach in Trimodality Therapy for Esophageal Cancer
Bibliographic record
Abstract
Purpose: Esophageal cancer remains a difficult cancer to cure despite aggressive therapy. A common strategy aimed at achieving cure in locally advanced esophageal cancers is to use neoadjuvant concurrent chemoradiotherapy followed by surgery ("trimodality" therapy). Post-operative complications following esophagectomy with gastric pull-up are significant events when they occur, including possible anastomotic leaks. Our goal is to investigate whether a relationship exists between these complications and radiation dose to either anastomotic end (proximal esophageal and distal gastric). For this purpose, we present dosimetric data describing the planned dose to different parts of the stomach with specific attention paid to the distal 2/3 of the organ which is most commonly used to form the gastro-esophageal anastomosis. Methods and Materials: An ethics board-approved retrospective analysis was performed on 37 consecutive patients at our institute who underwent neoadjuvant chemoradiotherapy followed by a radical esophagectomy. Patients were treated between January 1, 2008 and December 31, 2012. For each case, the 3D conformal plan was re-calculated once the stomach was contoured. Gastric contouring consisted of an overall organ contour from the gastro-esophageal junction to the pylorus. A series of sub-contours were then devised dividing the stomach into thirds: superior, middle and inferior third. The superior third was further subdivided into medial and lateral sub-components. At the time of simulation, patients were not given any specific instructions for food avoidance, and a subset were asked to drink oral contrast (< 100 ml). The mean radiation dose and V40 were computed for specified regions of the stomach. Results: A total of 37 patients were analyzed. The study cohort included 31 cases of esophageal adenocarcinoma and six cases of squamous cell carcinoma. Thirty-five of 37 cases involved the lower third of the esophagus. All surgeries were performed with a transthoracic approach, with minimally invasive ( Radiation dose varied between 4500-5040 cGy, given 180-200 cGy per day, often with a two phase approach with a smaller boost volume. The mean (range) dose of the medial superior, lateral superior, middle and inferior thirds of the stomach were 3919 cGy (46-5193), 2587 cGy (40-5077), 2569 cGy (27-4713) and 1304 cGy (14-4265) respectively. The calculated V40 for each gastric sub-segment was 72.3%, 34.0%, 34.7% and 12.5% respectively. Conclusions: There is no radiation sparing of the distal 2/3 of the stomach in patients treated with neoadjuvant radiotherapy for esophageal cancer. In some cases, doses approach or are equal to the prescribed dose. Surgeons may not be aware that tissues used to form an anastomosis with the proximal esophagus may have received significant dose. There is rationale to investigate a relationship between dose to the stomach and potential anastomotic complications in this patient population.
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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.004 | 0.001 |
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".