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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

Overall survival of PM (a) and UM (b) criteria-based response categories. Progression-free survival of PM (c) and UM (d) criteria-based response categories. Overall survival (e) and progression-free survival (f) of subgroups defined by combining PM and UM criteria
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Fig2: Overall survival of PM (a) and UM (b) criteria-based response categories. Progression-free survival of PM (c) and UM (d) criteria-based response categories. Overall survival (e) and progression-free survival (f) of subgroups defined by combining PM and UM criteria

Mentions: The median follow-up time for the study population was 25.2 months. Figure 2a, b depicts that both PM and UM methods determined response classification were predictive of OS (p < 0.0001). Patients with CMR achieved significantly better outcome than the non-CMR population. The median survival (MS) was 48.1 and 18.3 months for PM criteria-based CMR and non-CMR patients (p = 0.016). By the end of the last follow-up, the MS was not reached for UM criteria-determined CMR patients and was 22.0 months for non-CMR patients (p = 0.086). Similar findings were observed with respect to PFS results. Both PM and UM method-based response classifications were predictive of PFS (p < 0.0001) (Fig. 2c, d). The CMR group compared to the non-CMR group had median PFS of 33.7 months vs. 8.4 months (p = 0.005) for PM criteria and 25.5 vs. 12.4 months, respectively (p = 0.231), for UM criteria.Fig. 2


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)

Overall survival of PM (a) and UM (b) criteria-based response categories. Progression-free survival of PM (c) and UM (d) criteria-based response categories. Overall survival (e) and progression-free survival (f) of subgroups defined by combining PM and UM criteria
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4559091&req=5

Fig2: Overall survival of PM (a) and UM (b) criteria-based response categories. Progression-free survival of PM (c) and UM (d) criteria-based response categories. Overall survival (e) and progression-free survival (f) of subgroups defined by combining PM and UM criteria
Mentions: The median follow-up time for the study population was 25.2 months. Figure 2a, b depicts that both PM and UM methods determined response classification were predictive of OS (p < 0.0001). Patients with CMR achieved significantly better outcome than the non-CMR population. The median survival (MS) was 48.1 and 18.3 months for PM criteria-based CMR and non-CMR patients (p = 0.016). By the end of the last follow-up, the MS was not reached for UM criteria-determined CMR patients and was 22.0 months for non-CMR patients (p = 0.086). Similar findings were observed with respect to PFS results. Both PM and UM method-based response classifications were predictive of PFS (p < 0.0001) (Fig. 2c, d). The CMR group compared to the non-CMR group had median PFS of 33.7 months vs. 8.4 months (p = 0.005) for PM criteria and 25.5 vs. 12.4 months, respectively (p = 0.231), for UM criteria.Fig. 2

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