Biodistribution of 111In-labelled SCN-bz-DTPA-BC-2 MAb following loco-regional injection into glioblastomas

Int J Cancer. 1997 May 29;71(5):810-6. doi: 10.1002/(sici)1097-0215(19970529)71:5<810::aid-ijc19>;2-b.


We analyzed the biodistribution of the 111In-labelled murine anti-tenascin-C MAb BC-2 after intralesional injection in 15 glioblastoma patients. The activated ligand DTPA was conjugated via the isothiocyanato-benzyl group onto BC-2. Conjugates were labelled with 111In, displaying immunoreactivity greater than 90% and labelling efficiency of 99 +/- 1%. In contrast to i.v. injections, excellent tumor uptake was obtained by direct intralesional injection of conjugates that showed only slow systemic release. In serum, conjugates were found to be intact; in urine, only low-molecular-weight decay products were detected. In 8 patients, outflow from the site of injection into systemic circulation was low; daily activity in the serum and urine was found to be below 2% of the total injected radioactivity; most of the injected activity was retained within the tumor, resulting in effective half-lives of 58 +/- 5 hr. In contrast, higher outflow up to 10% of regionally injected 111In-DTPA-BC-2 MAb into systemic circulation resulted in considerable shortening of the effective half-lives to 20 to 40 hr in 7 patients. This outflow was found to correlate with tumor size and blood/brain barrier disruption. In one patient, HPLC analysis of tumor cyst fluid 3 and 6 days after intralesional injection revealed conjugates to be intact and allowed the estimate of about 70% of the total injected 111In-DTPA-BC-2 to be confined to tumor tissue. We conclude that different outflow patterns can be observed following locoregional injection of 111In-DTPA-BC-2, leading to considerable variations in the effective half-lives of isotopes within the tumor, requiring adjustment of the radiation dose in therapeutic trials.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Animals
  • Antibodies, Monoclonal / administration & dosage
  • Antibodies, Monoclonal / pharmacokinetics*
  • Brain Neoplasms / metabolism*
  • Female
  • Glioblastoma / metabolism*
  • Humans
  • Indium Radioisotopes*
  • Kinetics
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Middle Aged
  • Tenascin / immunology*
  • Tissue Distribution


  • Antibodies, Monoclonal
  • Indium Radioisotopes
  • Tenascin