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Metabolic tumor volume on interim PET is a better predictor of outcome in diffuse large B-cell lymphoma than semiquantitative methods.

Malek E, Sendilnathan A, Yellu M, Petersen A, Fernandez-Ulloa M, Driscoll JJ - Blood Cancer J (2015)

View Article: PubMed Central - PubMed

Affiliation: Hematology and Oncology, Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH, USA.

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Recent advances that incorporate combination chemotherapy and the anti-CD20-targeted agent rituximab (Rituxan) have improved the clinical outcome of patients diagnosed with diffuse large B-cell lymphoma (DLBCL), but only 60% of all DLBCL patients are potentially cured and achieve sustained progression-free survival (PFS)... Here, we compared the ability of MTV measurement by gradient- or threshold-based methods with semiquantitative SUVmax measurement on interim PET analyses to predict the PFS of DLBCL patients after initial therapy... Dichotomous visual interpretation of interim PET did not correlate with PFS (log-rank P=0.37)... Compared with the threshold-based method, the gradient-based method resulted in a statistically significant greater MTV in pretreatment, as well as interim PET images... Thresholds of ΔSUVmax and ΔMTV by this method were 72% and 52%, respectively... ΔMTV predicted PFS better than ΔSUVmax as the AUC for ΔMTV was significantly larger compared with that for for ΔSUVmax (AUC: 0.713 and AUC: 0.873; P: 0.0324) (Figure 1a)... From a total of 115 patients who achieved a ΔSUVmax >72% on interim PET/CT imaging, 77 (67%) had a ΔMTV >52%... Importantly, patients who achieved a ΔMTV >52% had a statistically significantly greater PFS compared with patients who achieved a ΔMTV <52% (hazard ratio: 1.37; confidence interval: 1.03–1.71, P=0.02; Figure 1b)... Among 115 patients who achieved a ΔSUVmax >72% on interim PET and those who demonstrated a ΔMTV >52% exhibited greater PFS (hazard ratio=1.37; confidence interval=1.03–1.71; P=0.02)... MTV measurement using a gradient-based method rendered assessment of a greater tumor volume compared with the threshold-based method... The two methods reveal a similar percent reduction in MTV and appear equivalent with respect to interim PET results... However, MTV measurement by either method after initial treatment was a better predictor of PFS compared with SUVmax reduction... Further analysis also revealed the underlying importance of MTV reduction on interim PET to predict PFS for patients who had also achieved a significant reduction in SUVmax (Figure 1b).

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(a) ROC curves for the MTV and ΔSUVmax for predicting PFS. MTV was measured by two different methods, threshold-based using 37% SUVmax as the threshold and gradient-based using the PET Edge software. The software calculates spatial derivatives along the tumor radii and then defines the tumor edge on the basis of derivative levels and the continuity of the tumor edge. All the measurements were performed by a single operator. The thresholds of ΔSUVmax and ΔMTV by ROC curve analysis were 72% and 52%, respectively. ΔMTV predicted PFS better than ΔSUVmax as the AUC for ΔMTV was significantly larger compared with the AUC for ΔSUVmax (AUCΔMTV: 0.713 and AUCΔSUVmax 0.873; P=0.0324). (b) Kaplan–Meier curve for patient who achieved adequate ΔSUVmax reduction (ΔSUVmax >72%) stratified to two groups based on ΔMTV. ΔMTV can predict PFS in a subset of patients who had significant SUVmax reduction on interim PET.
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fig1: (a) ROC curves for the MTV and ΔSUVmax for predicting PFS. MTV was measured by two different methods, threshold-based using 37% SUVmax as the threshold and gradient-based using the PET Edge software. The software calculates spatial derivatives along the tumor radii and then defines the tumor edge on the basis of derivative levels and the continuity of the tumor edge. All the measurements were performed by a single operator. The thresholds of ΔSUVmax and ΔMTV by ROC curve analysis were 72% and 52%, respectively. ΔMTV predicted PFS better than ΔSUVmax as the AUC for ΔMTV was significantly larger compared with the AUC for ΔSUVmax (AUCΔMTV: 0.713 and AUCΔSUVmax 0.873; P=0.0324). (b) Kaplan–Meier curve for patient who achieved adequate ΔSUVmax reduction (ΔSUVmax >72%) stratified to two groups based on ΔMTV. ΔMTV can predict PFS in a subset of patients who had significant SUVmax reduction on interim PET.

Mentions: As no difference was found between the two methods to determine ΔMTV and as the threshold-based method was more versatile, this method was used to correlate interim PET values with PFS. To identify an optimal threshold cutoff that could predict PFS more accurately, receiver operating characteristic (ROC) curve analysis was used. The area under the ROC curve (AUC) provides a measure of the accuracy of a diagnostic test and ranges from 0.5 (random guessing) to 1.0 (perfect test).11 Thresholds of ΔSUVmax and ΔMTV by this method were 72% and 52%, respectively. ΔMTV predicted PFS better than ΔSUVmax as the AUC for ΔMTV was significantly larger compared with that for for ΔSUVmax (AUCΔMTV: 0.713 and AUCΔSUVmax: 0.873; P: 0.0324) (Figure 1a). All patients who achieved an SUVmax reduction greater than the cutoff value determined by the ROC analysis (ΔSUVmax>72%) were then stratified into two groups based on an ΔMTV cutoff value > or <52%. From a total of 115 patients who achieved a ΔSUVmax >72% on interim PET/CT imaging, 77 (67%) had a ΔMTV >52%. Importantly, patients who achieved a ΔMTV >52% had a statistically significantly greater PFS compared with patients who achieved a ΔMTV <52% (hazard ratio: 1.37; confidence interval: 1.03–1.71, P=0.02; Figure 1b). Among 115 patients who achieved a ΔSUVmax >72% on interim PET and those who demonstrated a ΔMTV >52% exhibited greater PFS (hazard ratio=1.37; confidence interval=1.03–1.71; P=0.02).


Metabolic tumor volume on interim PET is a better predictor of outcome in diffuse large B-cell lymphoma than semiquantitative methods.

Malek E, Sendilnathan A, Yellu M, Petersen A, Fernandez-Ulloa M, Driscoll JJ - Blood Cancer J (2015)

(a) ROC curves for the MTV and ΔSUVmax for predicting PFS. MTV was measured by two different methods, threshold-based using 37% SUVmax as the threshold and gradient-based using the PET Edge software. The software calculates spatial derivatives along the tumor radii and then defines the tumor edge on the basis of derivative levels and the continuity of the tumor edge. All the measurements were performed by a single operator. The thresholds of ΔSUVmax and ΔMTV by ROC curve analysis were 72% and 52%, respectively. ΔMTV predicted PFS better than ΔSUVmax as the AUC for ΔMTV was significantly larger compared with the AUC for ΔSUVmax (AUCΔMTV: 0.713 and AUCΔSUVmax 0.873; P=0.0324). (b) Kaplan–Meier curve for patient who achieved adequate ΔSUVmax reduction (ΔSUVmax >72%) stratified to two groups based on ΔMTV. ΔMTV can predict PFS in a subset of patients who had significant SUVmax reduction on interim PET.
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fig1: (a) ROC curves for the MTV and ΔSUVmax for predicting PFS. MTV was measured by two different methods, threshold-based using 37% SUVmax as the threshold and gradient-based using the PET Edge software. The software calculates spatial derivatives along the tumor radii and then defines the tumor edge on the basis of derivative levels and the continuity of the tumor edge. All the measurements were performed by a single operator. The thresholds of ΔSUVmax and ΔMTV by ROC curve analysis were 72% and 52%, respectively. ΔMTV predicted PFS better than ΔSUVmax as the AUC for ΔMTV was significantly larger compared with the AUC for ΔSUVmax (AUCΔMTV: 0.713 and AUCΔSUVmax 0.873; P=0.0324). (b) Kaplan–Meier curve for patient who achieved adequate ΔSUVmax reduction (ΔSUVmax >72%) stratified to two groups based on ΔMTV. ΔMTV can predict PFS in a subset of patients who had significant SUVmax reduction on interim PET.
Mentions: As no difference was found between the two methods to determine ΔMTV and as the threshold-based method was more versatile, this method was used to correlate interim PET values with PFS. To identify an optimal threshold cutoff that could predict PFS more accurately, receiver operating characteristic (ROC) curve analysis was used. The area under the ROC curve (AUC) provides a measure of the accuracy of a diagnostic test and ranges from 0.5 (random guessing) to 1.0 (perfect test).11 Thresholds of ΔSUVmax and ΔMTV by this method were 72% and 52%, respectively. ΔMTV predicted PFS better than ΔSUVmax as the AUC for ΔMTV was significantly larger compared with that for for ΔSUVmax (AUCΔMTV: 0.713 and AUCΔSUVmax: 0.873; P: 0.0324) (Figure 1a). All patients who achieved an SUVmax reduction greater than the cutoff value determined by the ROC analysis (ΔSUVmax>72%) were then stratified into two groups based on an ΔMTV cutoff value > or <52%. From a total of 115 patients who achieved a ΔSUVmax >72% on interim PET/CT imaging, 77 (67%) had a ΔMTV >52%. Importantly, patients who achieved a ΔMTV >52% had a statistically significantly greater PFS compared with patients who achieved a ΔMTV <52% (hazard ratio: 1.37; confidence interval: 1.03–1.71, P=0.02; Figure 1b). Among 115 patients who achieved a ΔSUVmax >72% on interim PET and those who demonstrated a ΔMTV >52% exhibited greater PFS (hazard ratio=1.37; confidence interval=1.03–1.71; P=0.02).

View Article: PubMed Central - PubMed

Affiliation: Hematology and Oncology, Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH, USA.

AUTOMATICALLY GENERATED EXCERPT
Please rate it.

Recent advances that incorporate combination chemotherapy and the anti-CD20-targeted agent rituximab (Rituxan) have improved the clinical outcome of patients diagnosed with diffuse large B-cell lymphoma (DLBCL), but only 60% of all DLBCL patients are potentially cured and achieve sustained progression-free survival (PFS)... Here, we compared the ability of MTV measurement by gradient- or threshold-based methods with semiquantitative SUVmax measurement on interim PET analyses to predict the PFS of DLBCL patients after initial therapy... Dichotomous visual interpretation of interim PET did not correlate with PFS (log-rank P=0.37)... Compared with the threshold-based method, the gradient-based method resulted in a statistically significant greater MTV in pretreatment, as well as interim PET images... Thresholds of ΔSUVmax and ΔMTV by this method were 72% and 52%, respectively... ΔMTV predicted PFS better than ΔSUVmax as the AUC for ΔMTV was significantly larger compared with that for for ΔSUVmax (AUC: 0.713 and AUC: 0.873; P: 0.0324) (Figure 1a)... From a total of 115 patients who achieved a ΔSUVmax >72% on interim PET/CT imaging, 77 (67%) had a ΔMTV >52%... Importantly, patients who achieved a ΔMTV >52% had a statistically significantly greater PFS compared with patients who achieved a ΔMTV <52% (hazard ratio: 1.37; confidence interval: 1.03–1.71, P=0.02; Figure 1b)... Among 115 patients who achieved a ΔSUVmax >72% on interim PET and those who demonstrated a ΔMTV >52% exhibited greater PFS (hazard ratio=1.37; confidence interval=1.03–1.71; P=0.02)... MTV measurement using a gradient-based method rendered assessment of a greater tumor volume compared with the threshold-based method... The two methods reveal a similar percent reduction in MTV and appear equivalent with respect to interim PET results... However, MTV measurement by either method after initial treatment was a better predictor of PFS compared with SUVmax reduction... Further analysis also revealed the underlying importance of MTV reduction on interim PET to predict PFS for patients who had also achieved a significant reduction in SUVmax (Figure 1b).

No MeSH data available.


Related in: MedlinePlus