18F-FDG-PET and bone scintigraphy in the detection of bone metastasis in patients with suspected recurrent hormone-receptor positive breast cancer: A prospective evaluation
Bibliographic record
Abstract
1639 Objectives: Bone is a frequent site of metastasis in breast cancer patients. There have been variable reports about the sensitivity of FDG-PET for the detection of bone metastasis in breast cancer patients. Most of these studies were retrospective. The aim of this study was to evaluate prospectively the diagnostic accuracy of 18F-FDG-PET and 99mTc MDP bone scintigraphy in the detection of bone metastasis in patients with suspected recurrent hormonal receptor positive breast cancer. Methods: Patients with a prior history of estrogen and/or progesterone receptor positive breast cancer and a clinical suspicion of recurrence were approached for participation in this study. The initial imaging workup included bone scan, 18F-FDG-PET, thoracic, abdominal and pelvic CT. Diagnosis of recurrence and bone metastasis status was established on the basis of biopsy (when performed), multimodality imaging and clinical follow-up. Patients with a confirmed diagnosis of recurrence were treated and followed with 18F-FDG-PET at two months and bone scintigraphy and CT at six months. Other patients were followed clinically for at least 6 months. 18F-FDG-PET and bone scintigraphy were analyzed on a patient and a region basis. Bone lesions were considered positive when classified as probably or definitively abnormal by readers. Results: Thirty-two consecutive patients (31 women, 1 man) were enrolled in the study. Mean age was 57y (range 29-77). Three patients were excluded because of other confounding bone pathology (lymphoma, myeloma and histiocytosis X). The median follow-up time was 23 months. The median interval between 18F-FDG-PET and bone scintigraphy was 16 days. 20 patients were diagnosed with cancer recurrence. Of these, 14 patients had bone metastasis. Nine patients did not have recurrence and were followed clinically. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy were all 93% for 18F-FDG-PET, and 100%, 93%, 93%, 100% and 97% respectively for bone scintigraphy. There was no statistically significant difference between the two imaging modalities. However, in 7 patients, the bone scan revealed more lesions than 18F-FDG-PET, while in 3 patients 18F-FDG-PET showed more lesions than bone scintigraphy. Conclusions: 18F-FDG-PET has an overall diagnostic accuracy similar to bone scintigraphy for the assessment of bone metastasis in patients with hormonal receptor-positive breast cancer at the time of recurrence. Bone scintigraphy tended to reveal more osseous metastatic lesions than 18F-FDG-PET in this patient population. These two imaging modalities have a complementary role in this setting. Research Support (if any): Canadian Breast Cancer Research Alliance
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How this classification was reachedexpand
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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| 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 itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, 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".