Marker determination for response monitoring: radiotherapy and disappearance curves.

This paper reports the results of studies on the possible role of biochemical markers in monitoring the effects of ionizing radiations and in the follow-up of cancer patients submitted to radiotherapy. Three different case series were analyzed: patients with head and neck cancer, prostate carcinoma and residual thyroid tumors or uptaking metastases (131-Iodine therapy). Serum TPA and amylase were serially determined in patients with head and neck or thyroid cancer to measure the radiation damage to the salivary glands. In the former group a statistically significant correlation between the increase of both molecules and the total dose administered after the first day of treatment (2, 3, 4 or 6 Gy) was observed. In patients treated for thyroid cancer the damage to the salivary glands was revealed by an increase in TPA and amylase serum levels, dependent on the dose of 131-Iodine administered. Moreover, an association was demonstrated between pretreatment values of TPA in patients with head and neck tumors and prognosis: patients with values below the cutoff have significantly higher survival rates than those with higher values. In patients with prostate carcinoma PSA was confirmed to have better diagnostic and prognostic value than PAP. Patients with metastases show an inversion or lack of negative trend in PSA levels observed in the disease-free patients. This precedes the clinical diagnosis of metastases by 1 to 15 months.