Platinum compounds as radiosensitizers in strontium-89 metabolic radiotherapy.
OBJECTIVE
Strontium-89 is currently used for the treatment of painful bone metastases. This study reports on two preliminary experiences with low-dose platinum compounds, carboplatin and cisplatin, as radiosensitizers in 89Sr therapy.


METHODS
30 patients entered the carboplatin study: 15 patients (Group A) were treated with 148 MBq 89Sr followed by carboplatin (100 mg/m2 at 7 and 21 days) and 15 patients (Group B) were treated with 89Sr alone. 12 patients entered the cisplatin study: six patients (Arm 1) received 148 Mq 89Sr plus cisplatin (50 mg/m2) in two administrations (immediately before and 10 days after 89Sr injection) and six patients (Arm 2) received 89Sr plus two placebo administrations. Pain response was assessed 8 weeks after the therapy on the Wisconsin score modifications.


RESULTS
No clinically significant adverse effects or myelosuppression by platinum compounds were observed. In carboplatin study a pain response was observed in 20 of 27 (74%) evaluable patients, 13/15 in group A and 7/12 in group B. The pain response in the patients treated with 89Sr and carboplatin was clearly superior to that seen in the patients treated with 89Sr alone (P = 0.025), whereas survival was only marginally better in the combined treatment group (8.1 vs 5.7 months, P = 0.19). In cisplatin study a pain response was observed in 10 of 12 (83%) evaluable patients, 5/6 in Arm 1 and 4/6 in Arm 2.


CONCLUSIONS
Low-dose platinum compounds seem to enhance the effects of 89Sr radioisotope therapy on pain from bone metastases without relevant hematological toxicity.
Sciuto
R
R
Department of Nuclear Medicine, Regina Elena Cancer Institute, Rome, Italy.
Festa
A
A
Tofani
A
A
Pasqualoni
R
R
Semprebene
A
A
Cucchi
R
R
Ferraironi
A
A
Rea
S
S
Maini
C L
CL
D001859:Bone Neoplasms / Q000532:radiotherapy / Q000556:secondary*; D006801:Humans; D017671:Platinum Compounds / Q000627:therapeutic use*; D011838:Radiation-Sensitizing Agents / Q000627:therapeutic use*; D013326:Strontium Radioisotopes / Q000627:therapeutic use*
D017671:Platinum Compounds; D011838:Radiation-Sensitizing Agents; D013326:Strontium Radioisotopes