Purpose: Tumor hypoxia is associated with poor response to therapy. We have investigated whether pretreatment tumor hypoxia assessed by positron emission tomography (PET) with Cu-60 diacetyl-bis(N4-methylthiosemicarbazone) (60Cu-ATSM) predicts responsiveness to subsequent therapy in cervical cancer. Methods and Materials: Fourteen patients with biopsy-proved cervical cancer were studied by PET with 60Cu-ATSM before initiation of radiotherapy and chemotherapy. 60Cu-ATSM uptake was evaluated semiquantitatively by determining the tumor-to-muscle activity ratio (T/M) and peak slope index of tumor tracer uptake. All patients also underwent clinical PET with F-18 fluorodeoxyglucose (FDG) before institution of therapy. The PET results were correlated with follow-up evaluation (14-24 months). Results: Tumor uptake of 60Cu-ATSM was inversely related to progression-free survival and overall survival (log-rank p = 0.0005 and p = 0.015, respectively). An arbitrarily selected T/M threshold of 3.5 discriminated those likely to develop recurrence; 6 of 9 patients with normoxic tumors (T/M < 3.5) are free of disease at last follow-up, whereas all of 5 patients with hypoxic tumors (T/M > 3.5) have already developed recurrence. Similar discrimination was achieved with the peak slope index. The frequency of locoregional nodal metastasis was greater in hypoxic tumors (p = 0.03). Tumor FDG uptake did not correlate with 60Cu-ATSM uptake (r = 0.04; p = 0.80), and there was no significant difference in tumor FDG uptake between patients with hypoxic tumors and those with normoxic tumors. Conclusion: 60Cu-ATSM-PET in patients with cervical cancer revealed clinically relevant information about tumor oxygenation that was predictive of tumor behavior and response to therapy in this small study.
|Number of pages||6|
|Journal||International Journal of Radiation Oncology Biology Physics|
|State||Published - Apr 1 2003|
- Cervical cancer
- Positron emission tomography
- Response to therapy