KORTUC Phase II - Intra-tumoural Radiation Sensitizer in Patients With Locally Advanced/Recurrent Breast Cancer

Inclusion Criteria: * Patient age 18 years and over * Primary locally advanced breast cancer, or locally recurrent breast cancer with/without metastases (metastases, if present, should be stable or oligometastatic) * Radical/high dose palliative radiotherapy required for lifetime control of local morbidities * Patient physically and mentally fit for radical/high dose palliative radiotherapy * Target tumour accessible for intra-tumoural injection * Patient suitable/compliant with MR protocol * At least one tumour diameter ≥30 mm and ≤150 mm measurable by ultrasound or MR imaging * Patients with predicted life expectancy of 12 months or more * Negative pregnancy test before start of radiotherapy in women of child bearing potential and an ability/willingness to protect against pregnancy from consent and for 3 months post-radiotherapy * Patient offers written informed consent Exclusion Criteria: * Prior radiotherapy to the target area * Maximum diameter of target tumour \<30 mm or \>150mm measurable by ultrasound or MR * Anatomical location and/or extent of disease difficult to access for safe intra-tumoural drug injections, for example by virtue of contiguous major blood vessels and/or brachial plexus * Concomitant chemotherapy or biological therapy except Herceptin, Pertuzumab and Denosumab (all endocrine therapies and bisphosphonates are allowed concomitantly; other cytotoxics and biological therapies apart from those mentioned above should be stopped 3 weeks prior to RT) * Pregnancy or nursing * Hypersensitivity to any of the KORTUC ingredients