Daily cis-dichlorodiammineplatinum (II) as a radio-enhancer: A preliminary toxicity report

A combination of radiotherapy and daily administration of cis-dichlorodiammineplatinum (II) (CDDP) was given to six patients with locally advanced solid tumors including regional lymph-node metastases. Four of these patients had esophageal cancer (two with supraclavicular lymph-node metastases), one patient had oropharyngeal cancer (T₄N₁M₀), and one had recurrent cancer of the tongue with involvement of the skin of the neck. Radiotherapy in fractionated daily doses was given to three patients and the other three received superfractionated (two fractions/day) doses; CDDP was given within 15 min after radiotherapy at a dose of 8 mg/m² for fractionated and 4 mg/m² for superfractionated treatment. Evaluation of response in irradiated fields showed complete tumor control, as judged from histological examination in three patients, partial tumor regression in two (recurrent carcinoma of the tongue), and no response in one. One patient showed tumor progression in irradiated fields 7 weeks after treatment and two developed distant metastases. Due to severe leukopenia (3) occurring after the 3rd week of treatment, treatment was postponed in one patient and discontinued in two. Sepsis occurred in two patients and two patients developed severe thrombocytopenia (25,000/mm³ and 44,000/mm³). All patients needed red cell transfusions during therapy. Serum levels of sodium, potassium, calcium, and magnesium dropped in all patients, whereas renal function was stable. Only one patient showed severe gastrointestinal toxicity, expressed in vomiting and diarrhea. These preliminary data warrant further evaluation of this regimen, but it is clear that the treatment requires intensive supportive care.