Objective: The purpose of this study was to use color Doppler flow imaging to predict the response to preoperative chemotherapy in patients with Ewing's sarcoma or high-grade osteosarcomas early in treatment.
Subjects and methods: Color Doppler flow imaging was done in 31 patients before, during, and after chemotherapy. In each phase of treatment, semiquantitative changes in intratumoral blood flow, changes in maximum intratumoral Doppler shifts, and changes in resistive indexes of arteries feeding limbs that contained tumors relative to contralateral normal arteries were compared with the histopathologic response, as evaluated on the resected specimens.
Results: Before chemotherapy, pathologic flow was found in the extraosseous component of all but two patients. Resistive indexes in arteries that fed tumors were significantly lower (p < .001) than the resistive indexes in the contralateral normal arteries. Histopathologic response could not be predicted on the basis of the initial measurements of Doppler shifts and resistive indexes taken before or after the first cycle of chemotherapy. Histopathologic response could be predicted after the second cycle of chemotherapy. After the second cycle of chemotherapy, the resistive index in the arteries that fed tumors increased in eight of nine good respondents but did not change or decreased in eight of nine poor respondents (p = .03). Lower intratumoral Doppler shifts were measured in six of 10 good respondents but also in five of 13 poor respondents (p = .07). After the full course of chemotherapy, persistent lower resistive indexes were measured in the arteries that fed tumors in all poor respondents but one. Intratumoral flow and Doppler shifts further decreased in all good respondents but one. Changes in Doppler shifts (p = .001) and resistive indexes (p < .001) were statistically significant between good and poor respondents, irrespective of the tumor type studied.
Conclusion: Decreased or unaltered resistive index in the arteries that feed tumors in addition to persistent intratumoral flow and high-frequency Doppler shifts after two cycles of chemotherapy suggest poor histologic response to chemotherapy in osteosarcoma and Ewing's sarcoma. An increased resistive index after two cycles is indicative of good response.