Some craniopharyngioma patients often think that removing the tumor will be fine, but in fact, some craniopharyngioma is difficult to be completely removed through surgery, and the residual tumor will easily lead to recurrence. So how to avoid tumor recurrence? Internal radiation therapy is one of the commonly used means at present. 1.What should I do if craniopharyngioma is prone to recurrence after surgery? Craniopharyngioma grows in the saddle area of the skull and involves very important nerve and brain tissues; before the 1970s and 1980s, due to the immaturity and popularity of micro-neurosurgery technology in China, the surgery of craniopharyngioma could only be partially or mostly resected, and even in recent years, some regions with weak medical technology and lack of hardware equipment can still only partially or mostly resected. After partial or major resection of the tumor, the residual tumor will continue to grow and the residual cystic cells will continue to secrete cystic fluid, leading to tumor recurrence. In order to reduce tumor recurrence, the residual portion of the tumor should be followed up with internal radiation therapy, which is localized to the tumor lesion. Internal radiation therapy requires the use of a device called Ommaya capsule, in which a catheter at one end is placed into the residual tumor lesion, and the capsule at the other end of the catheter is buried under the scalp, so that the capsule fluid in the lesion can be suctioned out after the tumor recurrence and the pressure on the surrounding normal tissues can be reduced. According to the recurrence of tumor, radioisotope phosphorus 32P can be injected into the lesion periodically to inhibit or kill the residual tumor cells, so as to reduce the recurrence of tumor. 2.Do I need internal radiotherapy after total resection and partial resection surgery? For most cystic craniopharyngioma, or for patients who have a small amount of residual craniopharyngioma after resection and cannot undergo total resection, Ommaya capsule injection of radioisotope phosphorus 32P can be used for treatment. For patients with completely substantial craniopharyngiomas or tumors with a large number of calcified foci that cannot be resected, Ommaya capsule injection of radioisotope phosphorus 32P cannot be used to achieve the goal. With the maturation of microneurosurgery and neuroendoscopic techniques, the number of patients treated with internal radiation therapy is decreasing, and most craniopharyngiomas can be completely resected under microneurosurgical conditions combined with neuroendoscopic techniques. However, there are still a small number of patients who are difficult to achieve complete resection and require postoperative adjuvant therapy (e.g., internal radiation therapy, gamma knife therapy, etc.). In addition, for simple cystic craniopharyngioma, in order to reduce the possible risk of craniotomy, minimally invasive surgery can be performed, using local anesthesia under the guidance of stereotactic technology to place the Ommaya capsule, extract the fluid inside the capsule through the catheter, and then inject the radioisotope phosphorus 32P. 3.Will the radioactive material affect the normal brain tissues? In clinical practice, the radioactive isotope Phosphorus 32P is usually used, which has a very weak penetrating power of 3-5 mm. It is not dissolved in body fluids when injected into the body, thus it is not absorbed and mostly stays at the injection site or evenly adheres to the inner wall of the body cavity and the surface of the tumor tissue. Therefore, when we inject phosphorus 32P, it is basically confined to the capsule and has a therapeutic effect on the craniopharyngioma cyst wall cells, with little effect on the surrounding normal brain tissue. Moreover, before injecting the isotope, the doctor will calculate the dose of phosphorus-32P according to the size of the tumor to ensure that phosphorus-32P can adequately inhibit or kill the tumor cystic cells and avoid affecting the normal brain tissues around the cystic wall as much as possible. 4. With the increasing development of microsurgery technology and the maturity and popularity of neuroendoscopic technology, the degree of total resection of craniopharyngioma has become higher and higher. However, because there are many important structures around craniopharyngioma, it is still difficult to achieve 100% total resection rate for all craniopharyngioma. Therefore, for some craniopharyngiomas, especially those with calcification that are closely adhered to important surrounding tissues and cannot be separated, there will inevitably be a little residual. As long as there is residual tumor tissue, there is a possibility of recurrence.