What should we do if our tumor is not MIBG avid?

(Sam Saffron) #1

During our treatment we have had MIBG scans, prior to our operation scans showed some activity but the tumor was not “MIBG avid”, it lit up but not a lot.

We were told that this is common in about 10% of the cases, we tried a standard PET scan but it was not much better.

In Dr. Mark Gaze’s talk he talked about how some tissue lights up I-MIBG and other takes up Ga-DOTATATE, sometime actual disease can be invisible to MIBG scans.

I guess, my question is, should we push for alternating MIBG / DOTATATE PET scan during our regular scans going forward or just keep with MIBG?

(Parker Moss) #2

I would definitely push for gallium dototate as well. You need to know whether a) your tumour has benign differentiated (good news) or b) if your child is one of the usual cases that doesn’t have MIBG avidity but is still at risk of active disease. This is also important to know for future treatment modalities like MIBG therapy, which requires avidity.

(Donna Ludwinski) #3

Fascinating results from COG and European data (2014) – “focal” MYCN disease seem to do better – see http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4315489/

also heard Yanik present on better outcome for MIBG non-avid:

Results: Thirty of 343 patients (8.7%) in the analytic cohort had MIBG non-avid NBL (n = 1 from A3961 and n = 29 from A3973). Non-avid tumors were less likely to be adrenal primary tumors (34.5% vs. 57.2%; p = 0.02) or have bone metastases (36.7% vs. 61.7%; p = 0.008) and were more likely MYCN amplified (53.8% vs. 32.6%; p = 0.03). The rate of positivity for urine catecholamine levels (available from A3973 only) was lower in patients with non-avid NBL (66.7% vs. 91%; p < 0.001). Patients with MIBG non-avid NBL had a 5-year EFS of 50.0% compared to 38.7% for patients with MIBG avid NBL (p = 0.03). On backward-selected multivariate testing in high-risk patients, MIBG avidity was the sole adverse prognostic factor for EFS identified (hazard ratio 1.77; 95% confidence interval 1.04 – 2.99; p = 0.03); MYCN status, age, grade, MKI, and ploidy were not prognostic. Conclusions: MIBG non-avid NBL represents a distinct clinical subgroup with lower rates of adrenal primary tumors, bone metastasis, and catecholamine secretion. Despite being more likely to have MYCN amplified tumors, patients with MIBG non-avid NBL have superior outcomes compared to patients with MIBG avid NBL.

(Sam Saffron) #4

Thanks @Parker_Moss and @ludwinski that is very helpful to know!

I heard back from Dr. Mark Gaze as well!

(Parker Moss) #5

Where are the lesions? Depending on location a needle biopsy is another option?

(Sam Saffron) #6

At the moment Shalev is NED he has been NED since after our operation in Jan.

Originally the tumor took up a huge amount of his abdomen, it pushed one Kidney up, the other Kidney down, crossed the midline, we needed 2 stents.

(Nick) #7

Was the change in avidity between diagnosis and pre-operation not simply due to the effect of the chemotherapy on the tumour (cells)?

Ga-DOTATATE scans use a radio-labelled agent that attaches to somatostatin receptors on the surface of neuroblastoma cells. Just as not all neuroblastomas are MIBG-avid, not all neuroblastomas are somatostatin-positive either. At one point during treatment we had clear (18)F-FDG PET scan (no glycolytic metabolic activity), widespread uptake of MIBG, and Ga-DOTATATE that showed up more diseases than 123-MIBG in some areas and less in others. Sometimes these things throw up more questions than answers.

Having a positive Ga-DOTATATE scan is a precursor to being eligible for LUDO (Lutetium-177 DOTATATE) therapy.

(Sam Saffron) #8

Thank you so much for this info @birdni, it is very helpful.

Shalev’s tumour was not MIBG avid from the first scan, despite being extensive in the CT scan it just did not light up that much. It did respond extremely well the rapid COJEC. But the MIBG scans never really helped much in our case. We tried a PET scan halfway through induction and it also was not helpful.