(131)I radioimmunotherapy and fractionated external beam radiotherapy: Comparative effectiveness in a human tumor xenograft Journal Article

  


Authors: Barendswaard, E. C.; O'Donoghue, J. A.; Larson, S. M.; Tschmelitsch, J.; Welt, S.; Finn, R. D.; Humm, J. L.
Article Title: (131)I radioimmunotherapy and fractionated external beam radiotherapy: Comparative effectiveness in a human tumor xenograft
Abstract: This article compares the effectiveness of radiation delivered by a radiolabeled monoclonal antibody, 131I-labeled A33, that targets colorectal carcinoma, with that of 10 fractions of conventional 320 kV(p) x- rays. Methods: Human colorectal cancer xenografts (SW1222) ranging between 0.14 and 0.84 g were grown in nude mice. These were treated either with escalating activities (3.7-18.5 MBq) of 131I-labeled A33 or 10 fractions of 320 kVp x-rays (fraction sizes from 1.5 to 5 Gy). Tumor dosimetry was determined from a similar group of tumor-bearing animals by serial kill, tumor resection and counting of radioactivity in a gamma counter. The relative effectiveness of the two radiation therapy treatment approaches was compared in terms of tumor regrowth delay and probability of tumor cure. Results: The absorbed dose to tumor per MBq administered was estimated as 3.7 Gy (±1 Gy; 95% confidence interval). We observed a close to linear increase in tumor regrowth delay with escalating administered activity. Equitumor response of 131I monoclonal antibody A33 was observed at average radiation doses to the tumor three times greater than when delivered by fractionated external beam radiotherapy. The relationship between the likelihood of tumor cure and administered activity was less predictable than that for regrowth delay. Conclusion: The relative effectiveness per unit dose of radiation therapy delivered by 131I-labeled A33 monoclonal antibodies was approximately one third of that produced by fractionated external beam radiotherapy, when measured by tumor regrowth delay.
Keywords: controlled study; treatment outcome; nonhuman; comparative study; radiation dose; mouse; animal; animals; mice; radiotherapy dosage; radiotherapy; animal experiment; tumor xenograft; pathology; tumor antigen; radiation response; time; time factors; dose-response relationship, radiation; monoclonal antibody; colorectal neoplasms; immunology; antibodies, monoclonal; antigens, neoplasm; radioactive iodine; nude mouse; iodine radioisotopes; mice, nude; dosimetry; membrane glycoproteins; colorectal tumor; membrane protein; malignant neoplastic disease; neoplasm transplantation; gpa33 protein, mouse; radioimmunotherapy; cancer transplantation; tumor response; humans; human; female; priority journal; article; gpa33 protein, human; monoclonal antibody a33; colon cancer xenograft; monoclonal antibody i 131
Journal Title: Journal of Nuclear Medicine
Volume: 40
Issue: 10
ISSN: 0161-5505
Publisher: Society of Nuclear Medicine  
Date Published: 1999-10-01
Start Page: 1764
End Page: 1768
Language: English
PUBMED: 10520720
PROVIDER: scopus
DOI/URL:

https://www.scopus.com/inward/record.uri?eid=2-s2.0-0032589431&partnerID=40&md5=14539f4169858a155cf5eaed00652a17
Notes: Article -- Export Date: 16 August 2016 -- Source: Scopus
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MSK Authors
  1. Elsie C Barendswaard
    13 Barendswaard
  2. Jorg J Tschmelitsch
    7 Tschmelitsch
  3. Ronald D Finn
    279 Finn
  4. Joseph O'Donoghue
    151 O'Donoghue
  5. John Laurence Humm
    433 Humm
  6. Steven M Larson
    958 Larson
  7. Sydney Welt
    98 Welt
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