Use of colloids of chromic [ 32P] phosphate in treatment of solid tumors

• Published in: Nuclear medicine and biology Vol. 23; no. 7; pp. 907 - 910
• Main Authors: Zubillaga, M.B., Boccio, J.R., Nicolini, J.O., Ughetti, R., Lanari, E., Caro, R.A.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01.10.1996; Elsevier
• Subjects: 32P; Adenocarcinoma - metabolism; Adenocarcinoma - radiotherapy; Animals; Betatherapy; Biological and medical sciences; Brachytherapy; Chromium Compounds; Colloids; Female; Mammary Neoplasms, Experimental - metabolism; Mammary Neoplasms, Experimental - radiotherapy; Medical sciences; Metabolic Clearance Rate; Phosphates - pharmacokinetics; Phosphates - therapeutic use; Phosphorus Radioisotopes - pharmacokinetics; Phosphorus Radioisotopes - therapeutic use; Radiation therapy and radiosensitizing agent; Rats; Rats, Sprague-Dawley; Tissue Distribution; Treatment; Treatment with physical agents; Treatment. General aspects; Tumors; Rats; 32P; Brachytherapy; Betatherapy; Treatment; Tumors; Dose repartition; Solid tumor; Rat; Treatment efficiency; Rodentia; Single dose; Elimination; Experimental study; Radiotherapy; Colloid; Vertebrata; Mammalia; Sodium phosphate; Animal; Chromium phosphate; Comparative study; Therapeutic role
• ISSN: 0969-8051; 1872-9614
• DOI: 10.1016/S0969-8051(96)00123-0

In order to evaluate the effectiveness of an intratumorally single dose of chromic [ 32P] phosphate for the treatment of solid tumors, studies of bioelimination, biodistribution, and therapeutic action were carried out. Only for comparative purposes were similar studies undertaken using a solution of sodium [ 32P] orthophosphate-gelatin. Results show that when sodium [ 32P] orthophosphate-gelatin was intratumorally injected, the percentage of total elimination, after 32 days of treatment, was equal to 85.90 ± 8.70%, with a higher percentage in urine (64.50 ± 13.70%) than in feces (21.40 ± 4.50%). In biodistribution studies, the greater percentage was found in bone (15.54 ± 2.21%), whereas only 2.51 ± 0.39% remained in the tumor. When chromic [ 32P] phosphate was intratumorally injected, we found that the total elimination was equal to 51.70 ± 6.90%, with a higher amount in feces (32.70 ± 4.80%) than in urine (19.00 ± 3.60%). Biodistribution studies demonstrated that 28.93 ± 1.30% was still in the tumor and 19.01 ± 1.30% of the injected activity was found in the liver. On the other hand, when therapeutic action was evaluated, no tumoral regression was observed. These results demonstrate that the colloid of chromic [ 32P] phosphate cannot be used in the treatment of solid tumors as it mobilizes from the injection point, delivering a high dose to the entire organism.