recurrent juvenile pilocytic Astrocytoma

[Kroll2013]

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Dear Colleagues ,

I need your opinion concerning this young patient.

it is a 10 years old female.
she was diagnosed in 2014, at 6 yo of age, of a grade I JPA of the posterior fossa. clinically she developed headaches, left ear hearing loss and gait disturbance.
MRI showed a large PF tumor extending to the 4th ventricle through the left CPA causing a mass effect
posterior craniotomy was done.
pathology: 3*2.5cm grade I JPA, Ki67<2%

she was observed closely till august 2018
when she presented with increased headache.
MRI septembre 2018: small recurrence at the level of the left peduncle1.6*1.5*1.5 cm
posterior craniotomy: near complete resection, JPA grade I

MRI december 2018: enhancing intra-axial left brachium pontis mass of 1.5*1.6 cm that increased in size compared to sept post-op imaging. she has a definitive loss of hearing in the left ear. no other sequela.

what do you suggest as adjuvant treatment :
- adjusted chemotherapy (taking into consideration the risk of hearing toxicity
- adjuvant radiation to the tumor bed 50-54 Gy

ty a lot

 

[nkmiami]

I would send to an academic center or better yet, call up Tom Merchant. St judes will fly out pt and family and arrange/fund everything. You definitely want a highly specialized neurosurgeon to look at this for further resection.

 

[emt409]

Disclaimer, I do not know the peds data for this very well. But had a similar case in a non-peds patient. We SRS'd (18Gy/1fx) the recurrent focus of disease and has worked well thus far, with 2y f/u.

 

[Neuronix]

I'd be very hesitant to treat a brachium pontis mass to 18 Gy with SRS. What was your brainstem constraint ?

 

[evilbooyaa]

Had to google brachium pontis. In the cerebellum, near the brainstem for anybody else who isn't a master of latin based cranial anatomy.

Agree with treatment at pediatric center of excellence.

Assuming travel is impossible (and I'm certianly no pediatric expert) - this is a locally recurrent disease and she's already lost left sided hearing. After re-resection I think you could take it to 50.4 fractionated with IMRT and minimize dose to the contralateral cochlea (mean < 25-30 is what I'd shoot for). May also be a case worth evaluating for protons for better contralateral cochlea sparing.

Despite the fact most JPAs dont need RT, I think this girl being on her 2nd recurrence now (with less than 3 months in-between) demonstrates this is not acting like a JPA anymore.

 

[nkmiami]

Just as an aside,this sounds like posterior tracts- dorsal column medial lemniscus, these are fibers that carry proprioception along posterior brainstem. If you really had to, you could have more tolerance for radiation injury ie 18-20Gy as a) it its tract and b) proprioception is not critical brain like the rest of the brainstem. What would be the consequences of a lesion- not knowing where your arm is if you close your eyes or unable to feel vibration.? For grade 1/2 tumors, you really want to get everything out surgically if you can. In any case, I would go over it with a neuroradiologist

edit- this is the middle cerebellar peduncle