Evaluation of follow-up investigations in osteosarcoma patients: suggestions for an effective follow-up program

Follow-up programs for cancer patients aim at improving the overall prognosis by early detection of relapse. In this study, follow-up data from 72 osteosarcoma patients were received in order to determine the value of clinical examination (CE), lung CT-scan (CTL), chest X-ray (CXR), local X-ray (LXR), and bone scintigraphy (BS) in the detection of tumor recurrence.

Twenty-eight of 72 osteosarcoma patients presented with a total of 61 relapse sites. A continuous remission after relapse treatment could be achieved in 2/16 patients with first lung metastases, in 2/6 patients with local relapse, and in 3/19 patients with more than one lung metastasis. More than 90% of all relapses occurred within 3 years off primary therapy, respectively, within 3 years after detection of relapse. Local relapse and lung metastases were primarily diagnosed by CXR, CTL and CE. BS was the most important investigation to detect distant metastases. No relapse was found by routine X-ray of the primary tumor site.

To improve efficacy of follow-up programs and to reduce radiation load of nonrelapsed patients, the prognosis of patients with lung metastases or local recurrences and the time of high risk for a relapse should be taken into consideration. Since the number of patients who benefit from relapse therapy is still low, it remains to be shown whether an increased frequency of lung CT-scans or MRIs of the primary tumor site will improve early detection of relapse; and if so, whether that will enhance the chance for successful relapse treatment. CXR, CTL and CE should be performed routinely for at least 3 years after completion of therapy or relapse diagnosis. In contrast, BS and LXR appear not to be useful as routine investigations.