A case report of pseudoprogression followed by complete remission after proton-beam irradiation for a low-grade glioma in a teenager: the value of dynamic contrast-enhanced MRI

Abstract

A fourteen years-old boy was treated post-operatively with proton therapy for a recurrent low-grade oligodendroglioma located in the tectal region. Six months after the end of irradiation (RT), a new enhancing lesion appeared within the radiation fields. To differentiate disease progression from radiation-induced changes, dynamic susceptibility contrast-enhanced (DSCE) MRI was used with a T2* sequence to study perfusion and permeability characteristics simultaneously. Typically, the lesion showed hypoperfusion and hyperpermeability compared to the controlateral normal brain. Without additional treatment but a short course of steroids, the image disappeared over a six months period allowing us to conclude for a pseudo-progression. The patient is alive in complete remission more than 2 years post-RT.

Recent Technical Advances and Indications for Radiation Therapy in Low-Grade Glioma

“…Pseudoprogression has also been reported for grade I tumors in both the pediatric 27 and adult populations 30 and for grade II tumors as well 31 . In a series of WHO grade II and III patients, 8 of 37 (22%) grade II patients experienced pseudoprogression after chemoradiotherapy 32 .…”

Advanced Techniques Using Contrast Media in Neuroimaging

“…Preliminary findings of pseudoprogression using DSC-MRI and DCE-MRI suggest a decrease in rCBV and a moderate increase in vascular permeability (Figure 5) (80,81). …”

Pseudoprogression after concurrent chemoradiation therapy in glioblastoma

“…L'IRM de perfusion a aussi montré des résultats encourageants pour distinguer radionécrose et progression tumorale [25,42]. Tsien et al ont ainsi récemment proposé un nouveau biomarqueur basé sur l'IRM de perfusion.…”

“…Une avancée notable a été réalisée avec l'essai randomisé de phase III EORTC22981/2698 rapporté par Stupp et al, faisant de la chimioradiothérapie concomitante (CRT) le standard thérapeutique des glioblastomes nouvellement diagnostiqués. Dans cette étude, l'adjonction du temozolomide en concomitance à la radiothérapie (75 mg/m 2 par jour) poursuivi par six cycles de temozolomide adjuvant (150 à 200 mg/m 2 , 5 jours/28) a en effet montré un bénéfice en termes de survie globale à deux ans (27 versus 11 % ; IC 95 % : [21][22][23][24][25][26][27][28][29][30][31][32] et [7][8][9][10][11][12][13][14]) [37]. L'actualisation des données à cinq ans a confirmé le bénéfice en survie globale en faveur du bras combiné : 9,8 % de survie globale à cinq ans versus 1,9 % avec la radiothérapie seule (HR = 0,6 ; p < 0,0001) [36].…”