The incidence of primary hepatocellular carcinoma (HCC) has been rising worldwide over the last 25 years and is expected to increase until 2030 in some countries including the United States. In 2018, primary liver cancer represented the fifth most common cancer in men and the ninth in women and the second most common cause of cancer-related death worldwide [1]. Around 70% of patients are deemed unresectable and not suitable for transplant on presentation [2] and external beam radiation (both ‘SBRT’ and ‘PBRT’) are not recommended as first-line treatment options in this setting by the international guidelines.
Colorectal cancer (CRC) is a leading cause of cancer-associated death in Western populations and the third most frequent cause of cancer-related death worldwide. Population-based studies have shown that around 25–30% of patients diagnosed with CRC develop liver metastases during the course of their disease. Indications for curative-intended treatment of CRC liver metastases (CRCLM) have expanded in recent years. Unfortunately, despite the oncological and surgical advances made, only about 25% of patients affected are amenable to resection, which is regarded as the only way to achieve a cure. Historically, the indication for resection of liver metastases was based on tumour-related factors, for example tumour number, size and distribution in the liver. Currently, however, focus is placed on ‘Future Liver Remnant’ (FLR), with resectability defined as the ability to perform a complete (R0) resection, while preserving a sufficient FLR. The presence of unresectable extra-hepatic disease is still considered a contraindication to liver surgery. Liver resection can achieve 5-year survival rates of above 50%, compared to only around 5% for patients treated with palliative intent [3].
For these unresectable patients, a range of first-line loco-regional treatment options exist, each with advantages and limitations. The most prominent are Microwave Ablation (MWA), and transcatheter radiotherapy by Trans-Arterial Radioembolisation (TARE). Sadly, the reported Local Tumour Progression (LTP) rates for MWA and TARE are ~40% 3-5years post-administration [4, 5, 6, 7] representing a major unmet clinical need.
YntraDose is well positioned relative to these approaches because YntraDose is not dependent on intravascular administration which may be particularly advantageous in the treatment of poorly vascularised CRCLM. YntraDose can be used to treat many of the patients deemed ineligible to MWA and/or TARE. Moreover, the key limitations thought to contribute to the high recurrence rates are addressed by YntraDose such as no off-target radiation, the ability to treat lesions proximal to delicate structures, no need for general anaesthesia and the ability of the Interventional Radiologist to assess a predictable ablation zone within the same treatment session.