TL-201 SCINTIGRAPHY AND CHEMOTHERAPEUTIC RESPONSE IN RHABDOMYOSARCOMA

Thallium-201 scintigraphy was used to evaluate chemotherapeutic respon se in a case of rhabdomyosarcoma treated with epirubicin. A scintigrap hic semiquantitative index of tumor viability was correlated with MRI and clinical assessment. Both imaging studies were performed before th erapy and after treatment involving a cumulative dose of 640 mg/m2 of epirubicin. A very good inverse correlation was observed between Tl-20 1 uptake and tumor necrosis evaluated by MRI, leading to the conclusio n that sequential Tl-201 scintigraphy may have a role not only in deli neating the extent of the tumor, but in objectively assessing tumor re sponse to therapeutic interventions. The proposed scintigraphic method is much simpler to perform and less expensive than MRI-derived semiqu antitative measurement of tumor necrosis.