Accuracy of central neuro-imaging review of DIPG compared with histopathology in the International DIPG Registry

Abstract

Background Diffuse intrinsic pontine glioma (DIPG) remains a clinico-radiologic diagnosis without routine tissue acquisition. Reliable imaging distinction between DIPG and other pontine tumors with potentially more favorable prognoses and treatment considerations is essential. Methods Cases submitted to the International DIPG registry (IDIPGR) with histopathologic and/or radiologic data were analyzed. Central imaging review was performed on diagnostic brain MRIs (if available) by two neuro-radiologists. Imaging features suggestive of alternative diagnoses included nonpontine origin, <50% pontine involvement, focally exophytic morphology, sharply defined margins, and/or marked diffusion restriction throughout. Results Among 286 patients with pathology from biopsy and/or autopsy, 23 (8%) had histologic diagnoses inconsistent with DIPG, most commonly nondiffuse low-grade gliomas and embryonal tumors. Among 569 patients with centrally-reviewed diagnostic MRIs, 40 (7%) were classified as non-DIPG, alternative diagnosis suspected. The combined analysis included 151 patients with both histopathology and centrally-reviewed MRI. Of 77 patients with imaging classified as characteristic of DIPG, 76 (99%) had histopathologic diagnoses consistent with DIPG (infiltrating grade II-IV gliomas). Of 57 patients classified as likely DIPG with some unusual imaging features, 55 (96%) had histopathologic diagnoses consistent with DIPG. Of 17 patients with imaging features suggestive of an alternative diagnosis, eight (47%) had histopathologic diagnoses inconsistent with DIPG (remaining patients were excluded due to nonpontine tumor origin). Association between central neuro-imaging review impression and histopathology was significant (p < 0.001), and central neuro-imaging impression was prognostic of overall survival. Conclusions The accuracy and important role of central neuro-imaging review in confirming the diagnosis of DIPG is demonstrated.

Pediatric high-grade gliomas and the WHO CNS Tumor Classification—Perspectives of pediatric neuro-oncologists and neuropathologists in light of recent updates

“…And, when there are H3 K27M-specific therapies in future, clinical radiological diagnosis of DIPG would still include most, if not all H3 K27M mutant DIPG. 26 Furthermore, it remains unclear if all DIPG diagnosed by clinical radiological criteria are indeed sufficiently covered by the CNS5 diagnoses of DMG. According to von Bueren et al, up to 15% of DIPGs display H3 K27 wildtype, with a similarly poor prognosis as H3.3 K27M mutant DIPG.…”

“…If neuroradiologically defined DIPG with a similarly poor prognosis of DMG are indeed not fully covered by CNS5, then the consideration of introducing an additional neuroradiological layer for WHO CNS Tumor Classification might be helpful in future. 26 …”

Survival and prognostic factors of pediatric brainstem gliomas: a single institution experience of 96 cases

“…BSG magnetic resonance imaging results usually show enlarged pons occupying more than 50% of the pons crosssectional area, and DIPG may extend to the medulla oblongata [11,12]. On MRI, classical BSG is de ned as a low or equal signal on T1-weighted sequences and a high signal on T2-weighted sequences [13].…”

No wrong decisions in an all‐wrong situation. A qualitative study on the lived experiences of families of children with diffuse intrinsic pontine glioma

“…DIPG is usually diagnosed based on clinical symptoms and MRI, 2 but in the last 5 years and within the scope of recent preclinical trials, biopsies have (re)gained importance. [3][4][5] Due to its sensitive location and undefined borders, the tumor is nonresectable. The standard treatment for DIPG is focal radiotherapy (RT) commonly delivered over 6 weeks.…”

“…Problems with walking, coordination, swallowing, and speech are common symptoms among patients. DIPG is usually diagnosed based on clinical symptoms and MRI, 2 but in the last 5 years and within the scope of recent preclinical trials, biopsies have (re)gained importance 3–5 . Due to its sensitive location and undefined borders, the tumor is nonresectable.…”