Value of PET/CT and MR lymphography in treatment of prostate cancer patients with lymph node metastases.

PURPOSE: To determine the clinical value of two novel molecular imaging techniques: (11)C-choline positron emission tomography (PET)/computed tomography (CT) and ferumoxtran-10 enhanced magnetic resonance imaging (magnetic resonance lymphography [MRL]) for lymph node (LN) treatment in prostate cancer (PCa) patients. Therefore, we evaluated the ability of PET/CT and MRL to assess the number, size, and location of LN metastases in patients with primary or recurrent PCa. METHODS AND MATERIALS: A total of 29 patients underwent MRL and PET/CT for LN evaluation. The MRL and PET/CT data were analyzed independently. The number, size, and location of the LN metastases were determined. The location was described as within or outside the standard clinical target volume for elective pelvic irradiation as defined by the Radiation Therapy Oncology Group. Subsequently, the results from MRL and PET/CT were compared. RESULTS: Of the 738 LNs visible on MRL, 151 were positive in 23 of 29 patients. Of the 132 LNs visible on PET/CT, 34 were positive in 13 of 29 patients. MRL detected significantly more positive LNs (p < 0.001) in more patients than PET/CT (p = 0.002). The mean diameter of the detected suspicious LNs on MRL was significantly smaller than those detected by PET/CT, 4.9 mm and 8.4 mm, respectively (p < 0.0001). In 14 (61%) of 23 patients, suspicious LNs were found outside the clinical target volume with MRL and in 4 (31%) of 13 patients with PET/CT. CONCLUSION: In patients with PCa, both molecular imaging techniques, MRL and (11)C-choline PET/CT, can detect LNs suspicious for metastasis, irrespective of the existing size and shape criteria for CT and conventional magnetic resonance imaging. On MRL and PET/CT, 61% and 31% of the suspicious LNs were located outside the conventional clinical target volume. Therefore, these techniques could help to individualize treatment selection and enable image-guided radiotherapy for patients with PCa LN metastases.

Prognostic value of cytokeratin-positive bone marrow cells of gastric cancer patients.

BACKGROUND: Epithelial cells in the bone marrow of patients with gastric cancer suggest tumor dissemination; however, their prognostic implications are controversial. We prospectively evaluated the correlation of bone marrow findings, recurrence rate, and disease-free survival after long-term follow-up. METHODS: Bone marrow were aspirated from both iliac crests and stained with monoclonal cytokeratin (CK)-18 antibody in 209 patients before their initial operation. Patients were followed up for a median of 56 months. RESULTS: Overall, 39 (19%) of 209 patients and 15 (14%) of 109 R0-resected patients had CK-positive cells. CK-positive patients had more local, regional, and distant recurrence than CK-negative patients (P < .05). We found a significantly shorter disease-free survival (P < .05) in the patients with >2 CK-positive cells per 2 x 10(6) bone marrow cells (mean, 35 months) than in patients with 2 CK-positive cells per 2 x 10(6) bone marrow cells was an independent prognostic factor for tumor-related death (P < .05). CONCLUSIONS: Not only the mere presence of CK-positive epithelial cells in bone marrow, but also the cell number, correlates with prognosis. Our findings suggest that classifying CK-positive bone marrow cells in these patients will facilitate future studies.