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Evaluation of semi‐quantitative scoring system for metaiodobenzylguanidine (mIBG) scans in patients with relapsed neuroblastoma
Author(s) -
Messina Julia A.,
Cheng SuChun,
Franc Benjamin L.,
Charron Martin,
Shulkin Barry,
To Bao,
Maris John M.,
Yanik Gregory,
Hawkins Randall A.,
Matthay Katherine K.
Publication year - 2006
Publication title -
pediatric blood and cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.116
H-Index - 105
eISSN - 1545-5017
pISSN - 1545-5009
DOI - 10.1002/pbc.20777
Subject(s) - medicine , concordance , scoring system , neuroblastoma , soft tissue , correlation , concordance correlation coefficient , nuclear medicine , radiology , surgery , statistics , genetics , geometry , mathematics , biology , cell culture
Background The purpose of this study was to determine the accuracy of two semi‐quantitative scoring systems to assess response to 131 I‐metaiodobenzylguanidine (mIBG) therapy in recurrent neuroblastoma. Procedures Diagnostic mIBG scan pairs (n = 57) were collected for patients who underwent 131 I‐mIBG therapy for relapsed neuroblastoma. Two scoring systems were designated: Method 1, which divided the body into nine segments to view osteomedullary lesions with an additional tenth segment to assess soft tissue involvement; and Method 2, which divided the body into seven segments without a corresponding compartment for soft tissue involvement. Four nuclear medicine physicians independently assigned extension and intensity scores utilizing both methods, and separately recorded their impression of whether the post‐therapy scan had improved, not changed, or worsened. Inter‐ and intra‐observer concordance and correlation with overall response and progression‐free survival (PFS) were performed. Results Method 1 produced the highest inter‐observer concordance and was used to calculate the relative extension scores (post‐therapy score divided by pre‐therapy score), which correlated significantly with overall response. Patients who achieved complete response (CR) or partial response (PR) (n = 21) had lower relative extension scores, compared to those without response ( P < 0.001). The readers' overall impression associated highly ( P < 0.001) with the relative extension scores though results were less quantitative. Concordance was higher if initial scores were >5. Relative extension score did not predict PFS. Conclusion Semi‐quantitative scoring of mIBG scans provides a more reliable method of assessing response in patients with relapsed neuroblastoma than qualitative impression. The reproducibility and high inter‐observer concordance makes mIBG score an important component of overall response criteria in patients with recurrent neuroblastoma. Pediatr Blood Cancer © 2006 Wiley‐Liss, Inc.