(1) Treatment
1. Surgical treatment Surgery is the preferred treatment method for craniopharyngioma. The purpose of surgical treatment is to remove the tumor from the tumor to relieve the compression of the optic nerve chiasm and other nerve tissues, and to relieve the increase in intracranial pressure. Hypothalamic-pituitary dysfunction is difficult to recover. For solid tumors, surgery can remove the tumor; for cystic tumors, surgery can remove the cyst fluid to relieve the compression symptoms of the tumor. Because craniopharyngioma is a benign tumor, except for some adhesions with the optic chiasm, gray tubercle, pituitary stalk, hypothalamus, third ventricular floor, etc., most of them have glial reaction boundaries or arachnoid boundaries with surrounding tissue structures. , so in principle, we should strive to achieve total tumor resection, especially for pediatric patients, to prevent recurrence. Small craniopharyngiomas, especially intrasellar tumors, generally require transsphenoidal surgery, while large tumors should undergo transcranial surgery. Generally speaking, successful surgery can effectively relieve symptoms such as changes in vision and visual field caused by optic chiasm compression, headaches caused by high intracranial pressure, and restore adenohypophysis function. However, many suprasellar craniopharyngioma are closely connected with the surrounding brain tissue (especially the hypothalamus), which increases the difficulty of surgery. For these patients, complete tumor resection is not mandatory. Partial resection can be used. The disadvantage of partial resection is that the operation is difficult. The recurrence rate is very high. Depending on factors such as tumor growth site, size, shape, degree of calcification, location of the cyst, relationship with surrounding tissue and easy access to cerebrospinal fluid pathways, different approaches or methods need to be selected for surgery, and each has its own advantages and disadvantages.
(1) Frontobasal approach: The main structures that can be exposed include the optic nerve, optic chiasm, internal carotid artery, anterior cerebral artery, pituitary stalk, etc. It is suitable for post-chiasmatic type, large tumors growing in the sella and suprasellar, or extraventricular tumors growing antero-superiorly on the suprasellar optic chiasm. This approach can be further divided into several different surgical methods: such as through the subchiasmatic surgery, or if the optic chiasma is anterior, resection of the tuberculum sellae and the sphenoid plate to reach between the optic nerves, or open end plate surgery method, and the surgical method to reach the tumor from between the internal carotid artery and the optic nerve or optic tract.
(2) Pterional approach: similar to the temporal base approach, but has the shortest path and can directly reach the suprasellar area. It can expose the ipsilateral internal carotid artery, anterior cerebral artery, optic nerve and optic tract, below and behind the optic chiasm, pituitary stalk, floor of the third ventricle, interpeduncular fossa and upper slope, etc. It is suitable for intrasellar growth to the suprasellar side. Or extraventricular tumors in the suprasellar, subchiasmatic and postchiasmatic interpeduncular cisterns. This approach is currently the most widely used and is the main method for surgical resection of craniopharyngioma.
(3) Endplate approach: The posterior optic chiasm can be reached through the unilateral subfrontal approach, the pterional approach, and the bifrontal interhemispheric approach, and the endplate can be opened, and the exposure can be extended to the third Tumors outside the ventricle. Therefore, this approach is suitable for prechiasma type and intraventricular and extraventricular tumors that grow behind the suprasellar chiasm.
(4) Transcallosal or lateral ventricular approach: If the tumor grows into the third ventricle, the transcallosal approach (if the lateral ventricle is not significantly enlarged) or the lateral ventricular approach (interventricular foramen obstruction) Those who cause hydrocephalus). There are several ways to enter the third ventricle and expose the tumor: ① Isolate the unilateral fornix; ② Isolate a vein next to the interventricular foramen; ③ Enter under the choroid plexus; ④ Isolate the internal cerebral veins.
(5) Transsphenoidal approach: For tumors that are completely located in the sella or that slightly grow from the sella to the suprasellar or grow toward the sphenoid sinus, the transsphenoidal approach can be used.
(6) Other approaches and methods: In order to completely remove the tumor, sometimes the operation needs to be performed in stages, such as transcranial resection of the suprasellar tumor first, and then selective transsphenoidal resection of the intrasellar tumor, or resection of the tumor For huge tumors, a combined approach of two or more approaches is adopted.
Generally speaking, in the selection of surgical approach, the extraaxial approach or unilateral approach is more preferable than the transaxial approach or bilateral approach. To reach the site of the tumor, resection of functional tissue should be avoided whenever possible. Microscopic techniques should be used during surgery, and attention should be paid to distinguishing and protecting the layers and interfaces of the arachnoid membrane, which is conducive to safe tumor removal. After the tumor is exposed, the tumor is usually punctured to extract the cyst fluid first, creating a space for surgical separation of the tumor and separating the capsule from the arachnoid membrane. Then, the tumor capsule is resected. After the tumor shrinks, electrocoagulation and separation of the tumor supplying blood vessels are performed. During the operation, care should be taken to protect the anastomotic blood vessels around the median eminence that supply the optic chiasm and optic tract. The posterior part of the tumor and the part of the tumor that grows upward to the third ventricle have almost no large arterial blood supply, and the adhesions are not tight, but after the separation of the basilar artery and Be very careful with tumors in the posterior cerebral artery because the adhesions here are often tight. Calcification is often located at the bottom of the tumor, especially under the optic chiasm and optic nerve, and needs to be pulverized before resection. Sometimes the calcification of this part of the tumor is closely adhered to nerves, blood vessels, pituitary stalk, etc., making removal difficult. Tumors that grow toward the bottom of the third ventricle often form a glial reaction layer locally, and the separation of the cyst wall should be carried out within this layer. If the third ventricle has become thinner and becomes a glial layer (thick part containing nerve nuclei) has been pushed upward), the layer can be opened. The tumor capsule seen in the surgical field should be removed in pieces as much as possible. However, if the adhesions are tight, resection is not required to avoid damage to important nerve tissues and blood vessels such as the hypothalamus. The operation requires opening up the circulation of cerebrospinal fluid. If it is difficult to open the circulation, shunt surgery should be performed.
Whether surgery can achieve total resection is related to the following factors: ① Age. Children’s tumors have less adhesion to surrounding areas and are easier to remove. Generally, the younger the age, the easier it is to perform total resection, and the risk of complications is Also less.
Adult craniopharyngiomas are often tightly adherent to surrounding tissues (pituitary gland, hypothalamus, internal carotid artery, skull base arterial ring, optic chiasm and optic tract, etc.), and the tumor is deeply buried in the gray nodule, so total resection often requires surgery. There are many complications and high mortality rate. ②Initial surgery and recurrence surgery. The first surgery is easier than the re-operation for recurrent patients. There are more opportunities for total tumor resection and the mortality rate is also lower. ③Those with clinically obvious pituitary and hypothalamic dysfunction are only suitable for partial resection. ④ Depending on the location of the tumor, intrasellar and prechiasmatic types are easier to undergo total resection. For postchiasmatic and ventricular types, total or partial resection should be selected based on the adhesions between the cyst wall and the gray tubercle, hypothalamus, etc. In some cases, even if total surgical resection is performed, even if the postoperative CT scan is normal, there may still be residual tumor cells and recurrence. 15% to 30% of patients have hydrocephalus before surgery. If the symptoms are only caused by this, shunt surgery should be performed first. If the patient has consciousness disorder, severe hypothalamic symptoms, and cannot tolerate craniotomy, stereotactic cyst puncture can be performed first to remove the cyst fluid to reduce the local compression of the tumor. Surgery can be performed after the patient's condition is relieved, or part of the cyst can be extracted. After the liquid was injected, radionuclides were injected for internal irradiation therapy.
2. Radiotherapy As early as 1937, some people used radiation to treat craniopharyngioma. Generally, external irradiation is used. Since most craniopharyngiomas cannot be completely removed by surgery and are not sensitive to chemotherapy, it is recommended to add postoperative radiotherapy. The postoperative recurrence rate of craniopharyngioma is high, and the risk of reoperation is very high, so only radiation therapy can be used for patients with recurrence. In recent years, some people have used stereotaxic technology to implant colloidal phosphorus [32P] chromium acid, colloidal yttrium [90Y], and colloidal gold [198Au] to treat craniopharyngioma, and they have also achieved success. The advantage is that there is little radiation damage.
(1) External radiotherapy: Well-differentiated craniopharyngioma was once considered a radiation-insensitive tumor. Half a century ago, Carpenter et al. reported that a group of patients with craniopharyngioma showed significant improvement in their condition after radiotherapy. They believed that although the tumors were not destroyed by X-rays, cells with the ability to secrete and form cysts could be killed. However, there are still doubts about whether radiotherapy can destroy the epithelium of craniopharyngioma. In 1961, Kramer et al reported that subtotal tumor resection and ultrahigh-pressure radiotherapy achieved good results. Many subsequent studies have shown that radiotherapy can both increase survival and prolong the time for tumor recurrence. When surgery plus radiotherapy is used, the survival rate of patients is higher than that of patients with surgery alone, and the survival rate of patients without recurrence is higher.
However, the dangers of radiotherapy cannot be ignored. The main side effects of radiotherapy include: radiation optic neuritis, radiation necrosis of sella and perisellar brain tissue, hypopituitarism and dementia, etc. It can also induce meningiomas and sarcomas. , glioma, especially in children, radiotherapy can seriously damage intelligence. The incidence of these side effects increases with the dose. If the dose exceeds 60Gy, the incidence of optic neuritis can reach 30%, and the incidence of brain necrosis can reach 12.5%. Therefore, the radiation dose and treatment duration should be controlled within a certain range. Adenopituitarism caused by radiation therapy is mainly manifested by the deficiency of GH and LH/FSH. According to reports, the incidence of GH deficiency is nearly 100%, and it appears quickly (appearing 3 days after irradiation), and the growth of sick children is affected after several months. The incidence of LH/FSH deficiency is also high, but it appears later than GH deficiency, manifesting as sexual development disorders (children) or sexual insufficiency (adults). GH deficiency may be caused by damage to the hypothalamus, since treatment with GHRH is effective. It is currently believed that the site of LH/FSH deficiency is also in the hypothalamus. It is worth noting that some patients develop precocious puberty after radiotherapy, and the mechanism is unknown.
The treatment plan recommended in the literature is 50Gy/32 fractions every 6 weeks for children and 55Gy/35 fractions every 7 weeks for adults to reduce or avoid the occurrence of complications. In recent years, radiosurgery (γ knife, X knife) has been used to treat craniopharyngioma and has achieved certain results.
(2) Internal radiotherapy: Internal radiotherapy is a treatment in which radionuclides are placed into tumors. This method was created by Leksell in 1953. In the past, this treatment method was mostly through craniotomy, and transsphenoidal puncture was also used to carry out stereotaxic technology. Especially since the application of CT and MRI, directional puncture technology or directional puncture plus placement of a fluid reservoir are now mostly used. By extracting the cystic part of the tumor, symptoms can be improved quickly, and the risks and complications are significantly smaller than those of craniotomy. Domestic Naval General Hospital performed 385 treatments on 300 cases of craniopharyngioma, with an average follow-up of 4 years (6 months to 8 years). 92% of the patients recovered well, of which 72% had tumors disappearing and 12% had tumors shrinking by more than 80%. %, shrinkage by about 50% accounts for 8%, tumor enlargement accounts for 6.4% (mainly solid tumors), and death is only 1.6%. Internal radiotherapy is suitable for craniopharyngioma with a large amount of fluid in the cyst, but is not recommended for solid tumors and tumors with calcified cyst wall or thin cyst wall (radioactive nuclide can penetrate into the surrounding tissue). Polycystic tumors are also less effective. It is generally believed that shrinkage or disappearance of the cyst wall occurs 4 to 6 months after internal radiotherapy. Commonly used radionuclides include 32phosphorus (32P), 90yttrium (90Y), and 198gold (198Au).
3. There is currently no particularly effective drug for chemotherapy. Takahashi used bleomycin injected into the tumor cyst, which can reduce the secretion of cyst fluid and degenerate tumor cells.
Cavalheiro et al. treated a case of giant cystic craniopharyngioma by injecting bleomycin multiple times into the tumor cavity. The tumor cavity disappeared after 3 months, and the calcifications almost completely disappeared after 6 months, and the endocrine system completely returned to normal. However, if the drug leaks out of the capsule, it may cause damage to surrounding normal tissues. Clinical application has good effects on cystic tumors, but poor effects on mixed and solid tumors, and eventually the tumors relapse.
4. Other treatments: Patients with high intracranial pressure should be given dehydrating agents and diuretics immediately to reduce intracranial pressure. Such patients should make preoperative preparations and undergo surgical treatment as soon as possible. Those who have hypophyseal function before surgery should pay attention to supplying sufficient amounts of glucocorticoids to avoid pituitary crisis. Other adenohypophyseal hormones may not be supplied temporarily, because many patients can recover their adenohypophyseal function after surgery; if there is still hypophyseal function after surgery, corresponding treatment should be given. Hypopituitarism caused by surgery or radiation therapy is generally permanent and should be treated.
(2) Prognosis
1. Surgical effect and prognosis In the past, the total surgical resection rate of this tumor was low, and the death, disability and recurrence rates were high. Microsurgery has been carried out in the past 30 years, creating favorable conditions for protecting normal brain tissue, striving for total tumor resection, reducing damage to the hypothalamus and pituitary gland, reducing disability and mortality rates, and greatly improving the prognosis of patients. It has been reported that the surgical mortality rate of craniopharyngioma has dropped to 2%, the 10-year survival rate is 58% to 66%, and the recurrence rate is 7% to 26.5%. Domestic total tumor resection or active surgical resection performed by Tongji Medical University, People's Liberation Army General Hospital and other units has a surgical mortality rate of 4% to 6% and tumor recurrence of 10%, achieving good results.
2. Effects and prognosis of radiotherapy There are very few neurological sequelae caused by radiotherapy. From the perspective of neurological, intellectual, mental and endocrine functions, the long-term effects of radiotherapy for craniopharyngioma are no worse than surgical treatment in terms of functional changes. For patients who underwent total resection and subtotal resection followed by adjuvant radiotherapy, the results were similar between the two groups. Richmond reported that the survival rate for craniopharyngioma after radiotherapy for more than 10 years was 44% to 100%; Manaka evaluated the effect of radiotherapy on 125 patients with craniopharyngioma and found that the 5-year and 10-year survival rates were 88.9% and 7.6% respectively. , the control two groups were only 34.9% and 27.1% respectively. The average survival time in the radiotherapy group was more than 10 years, while that in the control group was 3.12 years. Kramer reported 6 cases of children under 15 years old who were asymptomatic for 20 years after radiotherapy and had no brain necrosis; Pollack reported radiotherapy cases, and after 14 to 45 months of follow-up, the symptoms of all cases improved and the tumor cyst wall shrank significantly.
3. The effect and prognosis of intratumoral/intratumoral chemotherapy. Takahashi reported 7 cases of craniopharyngioma treated with intratumoral injection of bleomycin, 4 cases of cystic tumors, with an average follow-up of 5 years. There was no recurrence in the scans; among the 3 cases with substantial disease, 1 died 1.5 months after the operation, and 2 cases temporarily improved but later died due to recurrence. Due to insufficient development of this therapy, its therapeutic effect is not yet certain.
The rate of GH deficiency in craniopharyngioma after surgery and radiotherapy is very high, but a considerable number of patients can still maintain almost normal growth without dwarfism, which is called no dwarfism. Growth hormone growth syndrome (growthwithoutgrowthhormonesyndrome), its mechanism has not yet been elucidated, some people believe that it is related to elevated levels of blood insulin and other peptide factors.