This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Colon and Rectum - Polyps and Carcinoma, 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 Radioimmunoguided 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 cancerColorectal cancerNon-small cell lung cancer