This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
In which case Immunoguided surgery is done ? 
Select and explain. 
A. Ca colon, B. Ca pancreas, C. Ca jejunum, D. Ca anal canal
A: Ca colon
Answer: A: Ca colon 
Explanation: Ans is 'a' ie Ca Colon Radioinununoguided surgery (RIGS) is a new technology capable of detecting minimal neoplastic lesions using radiocolloids, intraoperatively. It has numerous uses in oncology. it uses colloid radiotracers, monoclonal antibodies or non-immunological tracers. Its uses are Radioguided Occult Lesion Localization (ROLL) and Sentinel Lymph-Node Biopsy (SLNB). The malignancies mentioned in the above given web addresses of Pubmed, in which RIGS is being used are: Breast cancer - Colorectal cancer - Non small cell lung cancer