TY - JOUR
T1 - Evaluation of 11 C-methionine PET and anatomic MRI associations in diffuse intrinsic pontine glioma
AU - Tinkle, Christopher L.
AU - Duncan, Elizabeth C.
AU - Doubrovin, Mikhail
AU - Han, Yuanyuan
AU - Li, Yimei
AU - Kim, Hyun
AU - Broniscer, Alberto
AU - Snyder, Scott E.
AU - Merchant, Thomas E.
AU - Shulkin, Barry L.
N1 - Funding Information:
This work was supported in part by the American Lebanese Syrian Associated Charities (ALSAC), National Cancer Institute grant P30 CA021765 (St. Jude Cancer Center Support Grant), and National Cancer Institute grant 5R25CA23944 (ECD). No other potential conflict of interest relevant to this article was reported.
Publisher Copyright:
Copyright © 2019 by the Society of Nuclear Medicine and Molecular Imaging.
PY - 2019/3/1
Y1 - 2019/3/1
N2 - The role of metabolic imaging in the diagnosis, treatment, and response assessment of diffuse intrinsic pontine glioma (DIPG) is poorly defined. We investigated the uptake of 11 C-methionine in pediatric patients with newly diagnosed DIPG and evaluated the associations of 11 C-methionine PET metrics with conventional MRI indices and survival outcomes. Methods: Twenty-two patients with newly diagnosed DIPG were prospectively enrolled on an institutional review board–approved investigational study of 11 C-methionine PET. All patients underwent baseline 11 C-methionine PET/CT, and initial treatment-response scans after chemotherapy or radiation therapy were obtained for 17 patients. Typical and atypical DIPGs were assessed clinically and radiographically and defined by multidisciplinary consensus. Three-dimensional regions of interest, reviewed by consensus between a nuclear medicine physician and a radiation oncologist, were delineated after coregistration of PET and MR images. Associations of 11 C-methionine uptake intensity and uniformity with survival, along with associations between 11 C-methionine uptake and conventional MRI tumor indices over time, were evaluated. 11 C-methionine PET voxel values within regions of interest were assessed as threshold values across proportions of the study population, and 11 C-methionine uptake at baseline was assessed relative to MRI-defined tumor progression. Results: 11 C-methionine uptake above that of uninvolved brain tissue was observed in 18 of 22 baseline scans (82%) and 15 of 17 initial response scans (88%). 11 C-methionine avidity within MRI-defined tumor was limited in extent, with 11 of 18 positive baseline 11 C-methionine PET scans (61%) showing less than 25% 11 C-methionine–avid tumor. The increase in total tumor volume with 11 C-methionine PET was relatively limited (17.2%; interquartile range, 6.53%–38.90%), as was the extent of 11 C-methionine uptake beyond the MRI-defined tumor (2.2%; interquartile range, 0.55%–10.88%). Although baseline 11 C-methionine PET intensity and uniformity metrics did not correlate with survival outcomes, initial 11 C-methionine avidity overlapped with recurrent tumor in 100% of cases. A clinical diagnosis of atypical DIPG was associated with borderline significantly prolonged progression-free survival (P 5 0.07), yet 11 C-methionine PET indices at diagnosis did not differ significantly between atypical and typical DIPGs. Conclusion: Most newly diagnosed DIPGs are successfully visualized by 11 C-methionine PET. Baseline 11 C-methionine uptake delineates regions at increased risk for recurrence, yet intensity and uniformity metrics did not correlate with treatment outcomes in children with DIPG in this study.
AB - The role of metabolic imaging in the diagnosis, treatment, and response assessment of diffuse intrinsic pontine glioma (DIPG) is poorly defined. We investigated the uptake of 11 C-methionine in pediatric patients with newly diagnosed DIPG and evaluated the associations of 11 C-methionine PET metrics with conventional MRI indices and survival outcomes. Methods: Twenty-two patients with newly diagnosed DIPG were prospectively enrolled on an institutional review board–approved investigational study of 11 C-methionine PET. All patients underwent baseline 11 C-methionine PET/CT, and initial treatment-response scans after chemotherapy or radiation therapy were obtained for 17 patients. Typical and atypical DIPGs were assessed clinically and radiographically and defined by multidisciplinary consensus. Three-dimensional regions of interest, reviewed by consensus between a nuclear medicine physician and a radiation oncologist, were delineated after coregistration of PET and MR images. Associations of 11 C-methionine uptake intensity and uniformity with survival, along with associations between 11 C-methionine uptake and conventional MRI tumor indices over time, were evaluated. 11 C-methionine PET voxel values within regions of interest were assessed as threshold values across proportions of the study population, and 11 C-methionine uptake at baseline was assessed relative to MRI-defined tumor progression. Results: 11 C-methionine uptake above that of uninvolved brain tissue was observed in 18 of 22 baseline scans (82%) and 15 of 17 initial response scans (88%). 11 C-methionine avidity within MRI-defined tumor was limited in extent, with 11 of 18 positive baseline 11 C-methionine PET scans (61%) showing less than 25% 11 C-methionine–avid tumor. The increase in total tumor volume with 11 C-methionine PET was relatively limited (17.2%; interquartile range, 6.53%–38.90%), as was the extent of 11 C-methionine uptake beyond the MRI-defined tumor (2.2%; interquartile range, 0.55%–10.88%). Although baseline 11 C-methionine PET intensity and uniformity metrics did not correlate with survival outcomes, initial 11 C-methionine avidity overlapped with recurrent tumor in 100% of cases. A clinical diagnosis of atypical DIPG was associated with borderline significantly prolonged progression-free survival (P 5 0.07), yet 11 C-methionine PET indices at diagnosis did not differ significantly between atypical and typical DIPGs. Conclusion: Most newly diagnosed DIPGs are successfully visualized by 11 C-methionine PET. Baseline 11 C-methionine uptake delineates regions at increased risk for recurrence, yet intensity and uniformity metrics did not correlate with treatment outcomes in children with DIPG in this study.
KW - Brainstem glioma
KW - C-methionine PET
KW - DIPG
KW - Diffuse midline glioma
KW - MRI
KW - Pediatric
UR - http://www.scopus.com/inward/record.url?scp=85063299005&partnerID=8YFLogxK
U2 - 10.2967/jnumed.118.212514
DO - 10.2967/jnumed.118.212514
M3 - Article
C2 - 30072503
AN - SCOPUS:85063299005
SN - 0161-5505
VL - 60
SP - 312
EP - 319
JO - Journal of Nuclear Medicine
JF - Journal of Nuclear Medicine
IS - 3
ER -