Comparison of acute toxicity in patients treated with a 4-field box or IMRT to deliver elective pelvic nodal irradiation for localized high-risk prostate cancer.
Bibliographic record
Abstract
69 Background: To deliver elective pelvic nodal irradiation (EPNI), a 4-field box (4FB) has been a common technique. More recently, there are increasing reports of using IMRT to deliver EPNI. Even though studies show a clear dosimetric benefit to bowel and bladder, there is a lack of good data demonstrating decreased toxicity with the use of IMRT in this setting. Methods: From 2004-2010, 230 patients with localized high risk prostate cancer were enrolled into 3 sequential prospective phase I/II trials of delivering EPNI (45 Gy) along with a concomitant hypofractionated IMRT boost to the prostate (67.5 Gy total) in 25 fractions over 5 weeks time. All patients were to receive 3 years of adjuvant androgen deprivation. During the accrual period, the method used to deliver the EPNI portion of the treatment changed as new literature emerged about target volumes for EPNI. The 3 methods used to deliver EPNI in this large cohort were 1) 4FB, 2) IMRT with 2cm CTV margins around the pelvic vessels as suggested by Shih et al (IMRT-Shih), and 3) IMRT with nodal volumes as suggested by RTOG (IMRT-RTOG). Common Terminology Criteria for Adverse Events v3.0 was used to assess acute toxicity prospectively during treatment and then at 3 months. Results: For EPNI, 94 patients were treated with a 4FB, 53 were treated with IMRT-Shih, and 83 were treated with IMRT-RTOG. There were no acute grade 3 GI toxicities. Patients in the 4FB group had higher rates of acute grade ≥ 2 proctitis compared to the IMRT-Shih and IMRT-RTOG groups (16.0% vs 2.0% vs 2.4%, p=0.0009). The 4FB group also had higher rates of grade ≥ 2 flatulence compared to the 2 other IMRT groups (17.0% vs 7.6% vs 0%, p<0.0001). With regards to acute GU toxicities, patients in the 4FB group had higher rates of grade ≥ 3 urinary frequency compared to the 2 other IMRT groups (5.3% vs 0% vs 0%, p=0.027). Conclusions: In this non-randomized comparison, IMRT resulted in statistically significant decreases in acute proctitis, flatulence, and urinary frequency when compared to a 4FB technique to deliver EPNI in localized high risk prostate cancer. Analysis for possible confounding factors will be performed.
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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 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 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".