Poster Presentation Asia Pacific Neuroendocrine Tumour Society 2018

Renal function influences renal absorbed dosimetry, haematologic toxicity and early withdrawal from 177Lu-DOTATATE treatment   (#121)

Nadya Kisiel 1 , Rahul Ladwa 2 , Jye Smith 1 , Kevin Lee 1 , Stuart Ramsay 1 , Manoj Bhatt 1 , Stephen Nocher 1 , Matthew Burge 3 , David Wyld 3 , David Pattison 1
  1. Nuclear Medicine Department, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia
  2. Medical Oncology Department, Princess Alexandra Hospital, Brisbane, Queensland, Australia
  3. Medical Oncology Department, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia

BACKGROUND:

Peptide receptor radionuclide therapy (PRRT) is a safe and highly effective treatment for advanced neuroendocrine tumours (NET). Treatment is usually administered using fixed administered activity (7.4GBq) protocol without considering predictors of dose limiting toxicities to organs-at-risk. Our study examines the relationship between renal function and renal-absorbed-dosimetry (RAD) as predictors of haematologic toxicity.

METHODS:

Retrospective audit of patients with advanced NET treated with induction 177Lu-DOTATATE at Royal Brisbane and Women’s Hospital between September 2014 to August 2017. Renal function as measured by isotopic renal glomerular filtration rate (iGFR) was correlated with multiple timepoint RAD for first treatment cycle, and change in haematologic parameters (haemoglobin, white cell count, neutrophils, leukocytes, platelets) at baseline, nadir and last follow-up (<6 months after final treatment cycle). Toxicity was graded from 0 to 5 according to CTCAE v5.0 of the NCI.

RESULTS:

We analysed 61 patients with a mean age 66 (range 30-91) and predominantly small bowel (43%) and pancreatic (39%) NET. Patients received 1-4 cycles of PRRT at 8-week intervals with median cumulative administered activity of 33GBq. There was moderate negative correlation between cycle 1 RAD and baseline iGFR (-0.42). There was significantly higher RAD in patients who received <4 cycles LuTate (vs 4 cycles; 8.1Gy vs 6.2Gy, p=0.031) and grade 2-4 anaemia (vs grade 0-1; 9.1Gy vs 5.84Gy, p=0.004). These patients also had significantly lower baseline iGFR (<4 cycles LuTate, 66 vs 82ml/min/1.73sqm, p=0.005; and grade 2-4 anaemia, 64 vs 84ml/min/1.73sqm, p=0.001). There was no significant difference between cycle 1 RAD or baseline iGFR for other measured parameters of haematologic toxicity.

CONCLUSION:

There is moderate negative correlation between iGFR and RAD during induction PRRT. Patients with higher RAD or lower baseline iGFR are more likely to experience grade 2-4 anaemia or fail to complete 4 planned induction cycles due to myelosuppression.