Interstitial Brachytherapy For Limited (< 4 Cm) And Large (>= 4 Cm) Hepatic Metastases From Rare And Less Common Cancers

Background/Aim: Interstitial brachytherapy (iBT) seems to achieve higher local tumor control rates for lesions limited in size. The objective was to evaluate the efficacy and safety of iBT in the treatment of limited and large liver metastases from rare or less common cancers (RLCC). Patients and Methods: A total of 194 unresectable liver metastases categorized as limited (<4 cm, n=153, subgroup A) and large lesions (>= 4 cm, n=41, subgroup B) were treated. Clinical and image-based follow-up was conducted every 3 months after iBT. Results: Cumulative local recurrence (CLR) rate was 9.8% (19 recurrences; A: n = 16; B: n = 3). No significant difference in CLR was noted between subgroup A and B (A: 10.5%, B:7.3%, p=0.339). Median follow-up was 6.2 months (range=2.2- 92.9 months). Complication assessment revealed 5 severe adverse events (grade 3: 4.3%, grade 4 and 5: 0%) with 4 events in A and 1 event in B. Conclusion: IBT is a feasible, effective, and safe minimally invasive treatment for small and large liver metastases from RLCC.