Assessing rectal toxicity in a pilot study using intrarectal amifostine and concurrent radiation
Bibliographic record
Abstract
18579 Background: There is evidence that daily intrarectal amifostine can protect rectal mucosa during prostate cancer treatment. Instruments more sensitive than the RTOG score may discriminate small but clinically important reductions in proctitis, however these tools need further evaluation. This study used both the RTOG GI toxicity score and expanded prostate cancer index composite (EPIC), a patient-administered quality of life instrument, to evaluate toxicity. Methods: In this pilot study, patients with localized prostate cancer were given daily amifostine (MedImmune, INC., Gaithersburg, MD) which was placed per rectum 30–45 min before 3D conformal radiation (66–76 Gy in 2 Gy fractions to a volume based on PSA, Gleason score and clinical stage). The first 18 patients enrolled received 1gram of amifostine and the next 12 patients were given 2 grams. Toxicity was assessed at baseline, 5, and 7 weeks during treatment and 3, 6, 12, 18, and 24 months after radiation and amifostine treatment. RTOG grading, an EPIC score and proctoscopic examination were done. The EPIC questionaire is a validated instrument that consists of 50 quality of life questions related to urinary, bowel, sexual and hormonal domains. Two subsets of the bowel domain were used: “bowel function” (BF) targets symptom severity and “bowel bother,” (BB) assesses quality of life subscales. Results: Previously reported results demonstrate a clear trend towards protection from rectal toxicity using 2 gm as compared to a 1 gm amifostine dose. Here, we report that the EPIC-BF and EPIC-BB scores are both highly correlated with the RTOG toxicity score with a pearsons coefficient of 0.98 and 0.97 respectively at a median follow up of 24 mos. There was no significant change in the RTOG GI toxicity score over the course of treatment for either amifostine dose group. There was a statistically significant decrease in EPIC-BF score at 7 weeks (p = 0.04) and the EPIC-BB score showed a trend toward improvement (p = 0.07) at the same time point. The EPIC scores at all other time points were not statistically different from baseline. Conclusions: The EPIC score may be a more sensitive measure to detect acute toxicity associated with prostate cancer treatment but needs further investigation in the acute setting. No significant financial relationships to disclose.
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How this classification was reachedexpand
Direct model labels (unvalidated)
Per-model category and study-design labels from the labeling rounds. They are machine output, unvalidated, and the disagreement between models ships as data. No study design here is MEDLINE-validated yet.
| Model arm | Categories | Study design | Confidence |
|---|---|---|---|
| gemma | no category Domain: not available · Genre: Empirical About the Canadian research system: no · About a Canadian topic: no | Observational | low |
| gpt | no category Domain: not available · Genre: Empirical About the Canadian research system: no · About a Canadian topic: no | Other design | low |
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 | 0.004 | 0.005 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 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 | 0.001 |
| 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 itClassification
machine, unvalidatedLabeled directly by 2 models reading the full record.
The models disagree on parts of this classification; every voice is preserved in the section at the end of the page.
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".