Selective use of Peptide Receptor Radionuclide Therapy following comparative imaging of Ga-68 DOTATATE PET/CT against I-131 MIBG scintigraphy in a small Asian cohort of Adult Neuroblastoma.

Adult neuroblastoma (AN) is rare with an extremely poor prognosis. No standard therapy exists for this entity and treatment options are limited in recurrent or refractory disease. 131I-MIBG has been used in combination with myeloablative therapy before autologous bone marrow transplantation or in a salvage therapy setting. However, myelotoxicity is a dose-limiting factor in heavily pre-treated patients and response is not always sustained. Somatostatin receptor scintigraphy and theranostics with radiolabelled somatostatin receptor analogues are becoming more commonplace with the recognition of these receptors in over 90% of neuroblastoma cells. We describe three AN patients assessed for somatostatin receptor status and the novel use of 177Lu-based peptide recep-tor radionuclide therapy (PRRT) in two of them and a literature review.

A scoring model for predicting survival following primary tumour resection in stage IV colorectal cancer patients with unresectable metastasis.

BACKGROUND: Stage IV colorectal cancer patients with unresectable metastasis who undergo elective primary tumour resection experience heterogeneous post-operative survival. We aimed to develop a scoring model for predicting post-operative survival using pre-operative variables to identify patients who are least likely to experience extended survival following the procedure. METHODS: Survival data were collected from stage IV colorectal cancer patients who had undergone elective primary tumour resection between January 1999 and December 2007. Coefficients of significant covariates from the multivariate Cox regression model were used to compute individual survival scores to classify patients into three prognostic groups. A survival function was derived for each group via Kaplan-Meier estimation. Internal validation was performed. RESULTS: Advanced age (hazard ratio, HR 1.43 (1.16-1.78)); poorly differentiated tumour (HR 2.72 (1.49-5.04)); metastasis to liver (HR 1.76 (1.33-2.33)), lung (HR 1.37 (1.10-1.71)) and bone (HR 2.08 ((1.16-3.71)); carcinomatosis (HR 1.68 (1.30-2.16)); hypoalbuminaemia (HR 1.30 (1.04-1.61) and elevated carcinoembryonic antigen levels (HR 1.89 (1.49-2.39)) significantly shorten post-operative survival. The scoring model separated patients into three prognostic groups with distinct median survival lengths of 4.8, 12.4 and 18.6 months (p < 0.0001). Internal validation revealed a concordance probability estimate of 0.65 and a time-dependent area under receiver operating curve of 0.75 at 6 months. Temporal split-sample validation implied good local generalizability to future patient populations (p < 0.0001). CONCLUSION: Predicting survival following elective primary tumour resection using pre-operative variables has been demonstrated with the scoring model developed. Model-based survival prognostication can support clinical decisions on elective primary tumour resection eligibility.