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Metabolic response assessment with (18)F-FDG PET/CT: inter-method comparison and prognostic significance for patients with non-small cell lung cancer.

Wang J, Wong KK, Piert M, Stanton P, Frey KA, Kong FS - J Radiat Oncol (2015)

Bottom Line: Numerical percentage decrease of FDG uptake also showed significant correlations with survival, presenting a hazard ratio of 0.97 for both OS and PFS.A 75 % of SUV decrease was found to be the optimal cutoff to predict OS and 2-year progression.The percentage decrease provides an ordinal value that correlates with prolonged survival, recommending 75 % as the optimal threshold at identifying better responders.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiation Oncology, University of Michigan, Ann Arbor, MI USA ; Department of Radiation Oncology, Cancer Hospital & Institute, Chinese Academy of Medical Sciences (CAMS) & Peking Union Medical College (PUMC), Beijing, People's Republic of China.

ABSTRACT

Objective: This study aimed to (1) compare the agreement of two evaluation methods of metabolic response in patients with non-small cell lung cancer (NSCLC) and determine their prognostic value and (2) explore an optimal cutoff of metabolic reduction to distinguish a more favorable subset of responders.

Methods: This is a secondary analysis of prospective studies. Enrolled patients underwent 18F-PET/CT within 2 weeks before, during, and months after radiotherapy (post-RT). Metabolic response was assessed using both Peter MacCallum (PM) method of qualitative visual assessment and University of Michigan (UM) method of semiquantitative measurement. The agreement between two methods determined response, and their prediction of outcome was analyzed.

Results: Forty-four patients with median follow-up of 25.2 months were analyzed. A moderate agreement was observed between PM- and UM-based response assessment (Kappa coefficient = 0.434), unveiling a significant difference in CMR rate (p = 0.001). Categorical responses derived from either method were significantly predictive of overall survival (OS) and progression-free survival (PFS) (p < 0.0001). Numerical percentage decrease of FDG uptake also showed significant correlations with survival, presenting a hazard ratio of 0.97 for both OS and PFS. A 75 % of SUV decrease was found to be the optimal cutoff to predict OS and 2-year progression.

Conclusions: There was a modest discrepancy in metabolic response rates between PM and UM criteria, though both could offer predictive classification for survival. The percentage decrease provides an ordinal value that correlates with prolonged survival, recommending 75 % as the optimal threshold at identifying better responders.

No MeSH data available.


Related in: MedlinePlus

a Optimal cutoff of 75 % decrease in metabolic activity identified by receiver operating characteristic (ROC) analysis for predicting 2-year progression. Discriminative values of various cutoff of percentage decrease for overall survival (b) and progression-free survival (c)
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Fig3: a Optimal cutoff of 75 % decrease in metabolic activity identified by receiver operating characteristic (ROC) analysis for predicting 2-year progression. Discriminative values of various cutoff of percentage decrease for overall survival (b) and progression-free survival (c)

Mentions: Cox regression analysis showed a positive correlation between the numerical percentage decrease of NSUV-A and survival, resulting in the hazard ratio (HR) of 0.971 (95%CI, 0.955–0.988) and 0.971 (95%CI, 0.957, 0.986) from 1 % reduction of NSUV-A for OS and PFS, respectively. ROC analysis identified 75 % decrease in NSUV-A as the optimal cutoff, translating into a sensitivity of 80 % and specificity of 69 % for the 2-year progression (Fig. 3a). The discriminative values of cutoffs varying from 25 to 90 % reduction of NSUV-A at 5 % increments were analyzed for both OS and PFS. Besides the 25 % decrease proposed by EORTC criteria, a threshold of 75 and 60 % reduction was found by OS (p = 0.002) and PFS (p < 0.0001) analyses, respectively, to introduce the most discriminative significance (Fig. 3b, c). Using 25 and 75 % reduction as the cutoffs to stratify patients into three subgroups, we saw significantly different OS (Fig. 4a, 70.7 vs. 20.5 vs. 7.6 months, p < 0.0001) and PFS (Fig. 4b, 25.5 vs. 8.4 vs. 4.6, p < 0.0001) across groups.Fig. 3


Metabolic response assessment with (18)F-FDG PET/CT: inter-method comparison and prognostic significance for patients with non-small cell lung cancer.

Wang J, Wong KK, Piert M, Stanton P, Frey KA, Kong FS - J Radiat Oncol (2015)

a Optimal cutoff of 75 % decrease in metabolic activity identified by receiver operating characteristic (ROC) analysis for predicting 2-year progression. Discriminative values of various cutoff of percentage decrease for overall survival (b) and progression-free survival (c)
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4559091&req=5

Fig3: a Optimal cutoff of 75 % decrease in metabolic activity identified by receiver operating characteristic (ROC) analysis for predicting 2-year progression. Discriminative values of various cutoff of percentage decrease for overall survival (b) and progression-free survival (c)
Mentions: Cox regression analysis showed a positive correlation between the numerical percentage decrease of NSUV-A and survival, resulting in the hazard ratio (HR) of 0.971 (95%CI, 0.955–0.988) and 0.971 (95%CI, 0.957, 0.986) from 1 % reduction of NSUV-A for OS and PFS, respectively. ROC analysis identified 75 % decrease in NSUV-A as the optimal cutoff, translating into a sensitivity of 80 % and specificity of 69 % for the 2-year progression (Fig. 3a). The discriminative values of cutoffs varying from 25 to 90 % reduction of NSUV-A at 5 % increments were analyzed for both OS and PFS. Besides the 25 % decrease proposed by EORTC criteria, a threshold of 75 and 60 % reduction was found by OS (p = 0.002) and PFS (p < 0.0001) analyses, respectively, to introduce the most discriminative significance (Fig. 3b, c). Using 25 and 75 % reduction as the cutoffs to stratify patients into three subgroups, we saw significantly different OS (Fig. 4a, 70.7 vs. 20.5 vs. 7.6 months, p < 0.0001) and PFS (Fig. 4b, 25.5 vs. 8.4 vs. 4.6, p < 0.0001) across groups.Fig. 3

Bottom Line: Numerical percentage decrease of FDG uptake also showed significant correlations with survival, presenting a hazard ratio of 0.97 for both OS and PFS.A 75 % of SUV decrease was found to be the optimal cutoff to predict OS and 2-year progression.The percentage decrease provides an ordinal value that correlates with prolonged survival, recommending 75 % as the optimal threshold at identifying better responders.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiation Oncology, University of Michigan, Ann Arbor, MI USA ; Department of Radiation Oncology, Cancer Hospital & Institute, Chinese Academy of Medical Sciences (CAMS) & Peking Union Medical College (PUMC), Beijing, People's Republic of China.

ABSTRACT

Objective: This study aimed to (1) compare the agreement of two evaluation methods of metabolic response in patients with non-small cell lung cancer (NSCLC) and determine their prognostic value and (2) explore an optimal cutoff of metabolic reduction to distinguish a more favorable subset of responders.

Methods: This is a secondary analysis of prospective studies. Enrolled patients underwent 18F-PET/CT within 2 weeks before, during, and months after radiotherapy (post-RT). Metabolic response was assessed using both Peter MacCallum (PM) method of qualitative visual assessment and University of Michigan (UM) method of semiquantitative measurement. The agreement between two methods determined response, and their prediction of outcome was analyzed.

Results: Forty-four patients with median follow-up of 25.2 months were analyzed. A moderate agreement was observed between PM- and UM-based response assessment (Kappa coefficient = 0.434), unveiling a significant difference in CMR rate (p = 0.001). Categorical responses derived from either method were significantly predictive of overall survival (OS) and progression-free survival (PFS) (p < 0.0001). Numerical percentage decrease of FDG uptake also showed significant correlations with survival, presenting a hazard ratio of 0.97 for both OS and PFS. A 75 % of SUV decrease was found to be the optimal cutoff to predict OS and 2-year progression.

Conclusions: There was a modest discrepancy in metabolic response rates between PM and UM criteria, though both could offer predictive classification for survival. The percentage decrease provides an ordinal value that correlates with prolonged survival, recommending 75 % as the optimal threshold at identifying better responders.

No MeSH data available.


Related in: MedlinePlus