Poster Presentation Clinical Oncology Society of Australia Annual Scientific Meeting 2026

A retrospective analysis of Selective InternalRadiation Therapy (SIRT) and chemotherapyfor metastatic pancreatic adenocarcinoma (143562)

Sue ST Thang 1 , Vijayaragavan VM Muralidharan 2 , Manfred MS Spanger 2 , Patrick PP Page 3 , Adrian AF Fox 4 , Sean SM Mackay 2 , Lisa LM Miller 1 , Raffiela RG Garcia 1 , Ashleigh AP Poh 1 , Caroline CL Le 1 , Prasad PC Cooray 5
  1. Epworth HealthCare, Rowville, VIC, Australia
  2. Eastern Health, Box Hill, VIC, Australia
  3. i-Med Radiology, Box Hill, VIC, Australia
  4. Knox Private Hospital, Wantirna, VIC, Australia
  5. Department of Surgery, University of Melbourne, Austin Health, Heidelberg, VIC, Australia

Background

Pancreatic ductal adenocarcinoma (PDAC) is a major cause of cancer-related deaths in Australia, with
a 5-year survival rate of less than 13%. The liver is the most common site of PDAC metastasis, and is observed in over
50% of cases. Standard chemotherapy, including regimens such as FOLFIRINOX or nab-paclitaxel plus gemcitabine,
offer limited survival benefits, with median survival rates typically below one year. Selective internal radiation
therapy (SIRT) with Yttrium-90 (90Y) microspheres is used to target liver metastases, but the optimal chemotherapy
companion for SIRT in metastatic PDAC remains unknown.


Methods

We conducted a retrospective audit of 32 patients with metastatic PDAC treated with SIRT and
chemotherapy, and evaluated the clinical outcomes associated with platinum-based versus non-platinum-based
regimens.


Results

Patients who received platinum-based chemotherapy alongside SIRT had a median PFS of 10 months,
compared to 2 months in those treated with non-platinum-based regimens. Stratified analysis revealed that patients
receiving platinum-based chemotherapy in the first-line setting achieved a median post-SIRT survival of 16 months,
compared to 4 months for those treated in later lines. For non-platinum-based regimens, median post-SIRT survival
was 9 months in the first-line and 6 months in later lines. Median OS from Stage IV diagnosis was 17 months for
patients with liver-only metastases and 15 months for those with additional extra-hepatic disease, suggesting that
liver disease burden remains a dominant driver of outcomes.


Conclusions

These findings describe survival outcomes among patients treated with SIRT and chemotherapy for
metastatic PDAC in a real-world setting. Longer observed survival was seen in patients who received platinum-based
chemotherapy alongside SIRT, particularly in the first-line setting. Given the descriptive design and small sample size,
these findings should be interpreted as hypothesis-generating and may inform future prospective evaluation of SIRT–
chemotherapy combinations