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An exploratory study of volumetric analysis for assessing tumor response with (18)F-FAZA PET/CT in patients with advanced non-small-cell lung cancer (NSCLC).

Kerner GS, Bollineni VR, Hiltermann TJ, Sijtsema NM, Fischer A, Bongaerts AH, Pruim J, Groen HJ - EJNMMI Res (2016)

Bottom Line: In the primary tumor of all seven patients, median (18)F-FDG standard uptake value (SUVmax) decreased significantly (p = 0.03).There was no significant decrease in (18)F-FAZA uptake as measured with T/Bgmax (p = 0.24) or the FHV (p = 0.35).Additionally, volumetric voxel-by-voxel analysis showed that low hypoxic tumors did not significantly change in hypoxic status between baseline and two cycles of chemotherapy, whereas highly hypoxic tumors did.

View Article: PubMed Central - PubMed

Affiliation: Department of Pulmonary Diseases, University Medical Center Groningen, University of Groningen, Hanzeplein 1, P.O.Box 30.001, 9700 RB, Groningen, The Netherlands. g.s.m.a.kerner@umcg.nl.

ABSTRACT

Background: Hypoxia is associated with resistance to chemotherapy and radiotherapy and is randomly distributed within malignancies. Characterization of changes in intratumoral hypoxic regions is possible with specially developed PET tracers such as (18)F-fluoroazomycin arabinoside ((18)F-FAZA) while tumor metabolism can be measured with 2-deoxy-2-[(18)F]fluoro-D-glucose ((18)F-FDG). The purpose of this study was to study the effects of chemotherapy on (18)F-FAZA and (18)F-FDG uptake simultaneously in non-small-cell lung cancer (NSCLC) patients

Methods: At baseline and after the second chemotherapy cycle, both PET/CT with (18)F-FDG and (18)F-FAZA was performed in seven patients with metastasized NSCLC. (18)F-FAZA and (18)F-FDG scans were aligned with deformable image registration using Mirada DBx. The primary tumors were contoured, and on the (18)F-FDG scan, volumes of interest (VOI) were drawn using a 41 % adaptive threshold technique. Subsequently, the resulting VOI was transferred to the (18)F-FAZA scan. (18)F-FAZA maximum tumor-to-background (T/Bgmax) ratio and the fractional hypoxic volume (FHV) were assessed. Measurements were corrected for partial volume effects. Finally, a voxel-by-voxel analysis of the primary tumor was performed to assess regional uptake differences.

Results: In the primary tumor of all seven patients, median (18)F-FDG standard uptake value (SUVmax) decreased significantly (p = 0.03). There was no significant decrease in (18)F-FAZA uptake as measured with T/Bgmax (p = 0.24) or the FHV (p = 0.35). Additionally, volumetric voxel-by-voxel analysis showed that low hypoxic tumors did not significantly change in hypoxic status between baseline and two cycles of chemotherapy, whereas highly hypoxic tumors did. Individualized volumetric voxel-by-voxel analysis revealed that hypoxia and metabolism were not associated before and after 2 cycles of chemotherapy.

Conclusions: Tumor hypoxia and metabolism are independent dynamic events as measured by (18)F-FAZA PET and (18)F-FDG PET, both prior to and after treatment with chemotherapy in NSCLC patients.

No MeSH data available.


Related in: MedlinePlus

Per patient comparison of regional voxel distribution in the primary tumor of 18F-FAZA (T/Bg, vertical axis) versus 18F-FDG (SUV, horizontal axis) at baseline and after 2 cycles of chemotherapy. The horizontal axis represents the 18F-FDG uptake in SUV. The vertical axis represents the 18F-FAZA uptake in tumor-to-background ratio. Blue represents voxel distribution assessed at baseline, while green represents voxel distribution assessed after 2 cycles of chemotherapy. 18F-FDG data of patient 4 was not available after 2 cycles of chemotherapy
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Fig1: Per patient comparison of regional voxel distribution in the primary tumor of 18F-FAZA (T/Bg, vertical axis) versus 18F-FDG (SUV, horizontal axis) at baseline and after 2 cycles of chemotherapy. The horizontal axis represents the 18F-FDG uptake in SUV. The vertical axis represents the 18F-FAZA uptake in tumor-to-background ratio. Blue represents voxel distribution assessed at baseline, while green represents voxel distribution assessed after 2 cycles of chemotherapy. 18F-FDG data of patient 4 was not available after 2 cycles of chemotherapy

Mentions: In pre-chemotherapy in 4/7 patients, a weak relationship between FAZA T/Bg and 18F-FDG SUV was observed with R2 values between 0.12 and 0.30 (Fig. 1). After 2 cycles chemotherapy, only in two patients, R2 was 0.24 and 0.33; in the other patients, no relationship was observed between 18F-FDG SUV and 18F-FAZA T/Bg (Fig. 1). In one patient, a very weak relationship between 18F-FAZA T/Bg and 18F-FDG SUV persisted at baseline and after 2 cycles of chemotherapy (R2 = 0.14 and R2 = 0.33, respectively).Fig. 1


An exploratory study of volumetric analysis for assessing tumor response with (18)F-FAZA PET/CT in patients with advanced non-small-cell lung cancer (NSCLC).

Kerner GS, Bollineni VR, Hiltermann TJ, Sijtsema NM, Fischer A, Bongaerts AH, Pruim J, Groen HJ - EJNMMI Res (2016)

Per patient comparison of regional voxel distribution in the primary tumor of 18F-FAZA (T/Bg, vertical axis) versus 18F-FDG (SUV, horizontal axis) at baseline and after 2 cycles of chemotherapy. The horizontal axis represents the 18F-FDG uptake in SUV. The vertical axis represents the 18F-FAZA uptake in tumor-to-background ratio. Blue represents voxel distribution assessed at baseline, while green represents voxel distribution assessed after 2 cycles of chemotherapy. 18F-FDG data of patient 4 was not available after 2 cycles of chemotherapy
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4835394&req=5

Fig1: Per patient comparison of regional voxel distribution in the primary tumor of 18F-FAZA (T/Bg, vertical axis) versus 18F-FDG (SUV, horizontal axis) at baseline and after 2 cycles of chemotherapy. The horizontal axis represents the 18F-FDG uptake in SUV. The vertical axis represents the 18F-FAZA uptake in tumor-to-background ratio. Blue represents voxel distribution assessed at baseline, while green represents voxel distribution assessed after 2 cycles of chemotherapy. 18F-FDG data of patient 4 was not available after 2 cycles of chemotherapy
Mentions: In pre-chemotherapy in 4/7 patients, a weak relationship between FAZA T/Bg and 18F-FDG SUV was observed with R2 values between 0.12 and 0.30 (Fig. 1). After 2 cycles chemotherapy, only in two patients, R2 was 0.24 and 0.33; in the other patients, no relationship was observed between 18F-FDG SUV and 18F-FAZA T/Bg (Fig. 1). In one patient, a very weak relationship between 18F-FAZA T/Bg and 18F-FDG SUV persisted at baseline and after 2 cycles of chemotherapy (R2 = 0.14 and R2 = 0.33, respectively).Fig. 1

Bottom Line: In the primary tumor of all seven patients, median (18)F-FDG standard uptake value (SUVmax) decreased significantly (p = 0.03).There was no significant decrease in (18)F-FAZA uptake as measured with T/Bgmax (p = 0.24) or the FHV (p = 0.35).Additionally, volumetric voxel-by-voxel analysis showed that low hypoxic tumors did not significantly change in hypoxic status between baseline and two cycles of chemotherapy, whereas highly hypoxic tumors did.

View Article: PubMed Central - PubMed

Affiliation: Department of Pulmonary Diseases, University Medical Center Groningen, University of Groningen, Hanzeplein 1, P.O.Box 30.001, 9700 RB, Groningen, The Netherlands. g.s.m.a.kerner@umcg.nl.

ABSTRACT

Background: Hypoxia is associated with resistance to chemotherapy and radiotherapy and is randomly distributed within malignancies. Characterization of changes in intratumoral hypoxic regions is possible with specially developed PET tracers such as (18)F-fluoroazomycin arabinoside ((18)F-FAZA) while tumor metabolism can be measured with 2-deoxy-2-[(18)F]fluoro-D-glucose ((18)F-FDG). The purpose of this study was to study the effects of chemotherapy on (18)F-FAZA and (18)F-FDG uptake simultaneously in non-small-cell lung cancer (NSCLC) patients

Methods: At baseline and after the second chemotherapy cycle, both PET/CT with (18)F-FDG and (18)F-FAZA was performed in seven patients with metastasized NSCLC. (18)F-FAZA and (18)F-FDG scans were aligned with deformable image registration using Mirada DBx. The primary tumors were contoured, and on the (18)F-FDG scan, volumes of interest (VOI) were drawn using a 41 % adaptive threshold technique. Subsequently, the resulting VOI was transferred to the (18)F-FAZA scan. (18)F-FAZA maximum tumor-to-background (T/Bgmax) ratio and the fractional hypoxic volume (FHV) were assessed. Measurements were corrected for partial volume effects. Finally, a voxel-by-voxel analysis of the primary tumor was performed to assess regional uptake differences.

Results: In the primary tumor of all seven patients, median (18)F-FDG standard uptake value (SUVmax) decreased significantly (p = 0.03). There was no significant decrease in (18)F-FAZA uptake as measured with T/Bgmax (p = 0.24) or the FHV (p = 0.35). Additionally, volumetric voxel-by-voxel analysis showed that low hypoxic tumors did not significantly change in hypoxic status between baseline and two cycles of chemotherapy, whereas highly hypoxic tumors did. Individualized volumetric voxel-by-voxel analysis revealed that hypoxia and metabolism were not associated before and after 2 cycles of chemotherapy.

Conclusions: Tumor hypoxia and metabolism are independent dynamic events as measured by (18)F-FAZA PET and (18)F-FDG PET, both prior to and after treatment with chemotherapy in NSCLC patients.

No MeSH data available.


Related in: MedlinePlus