Childhood tumor

Surgical treatment

The treatment of medulloblastoma is mainly surgical resection and postoperative radiotherapy, and some cases may be supplemented with chemotherapy.

How is surgery treated?

Surgical resection is the main method to treat this disease. Posterior median craniotomy should be performed to remove the tumor completely or nearly completely, so as to restore the obstruction of the fourth ventricle.

For patients with significant increase in intracranial pressure, the increase in intracranial pressure should be removed first, and tumor resection or cerebrospinal fluid shunt surgery can be performed to remove the tumor as much as possible. Some people believe that extensive tumor resection is easy to cause tumor broadcast, and advocate only partial tumor resection and opening up the fourth ventricle can be done. The operation can be performed with a median occipital incision, after biting the posterior fossa bone, the swelling and widening of the cerebellar vermis can be seen, or the tumor can be seen in the cisterna occipitalis, and the direction of the suction device is pointed to the direction of the inferior aquifer. The tunnel aspiration method can be used. Once the upper pole is sucked through, a large amount of cerebrospinal fluid can be seen gushes out, and the subsequent expansion of the aquaquine opening can be clearly seen. At this time, the boundary between the tumor and the bottom of the fourth ventricle can be seen. If the tumor is hard fiber type, it can be stripped to its sides, blocking its blood supply source, and the tumor can often be removed intact. In addition, hemostasis should be thorough during operation, blood vessels on the surface of the tumor should be coagulated with bipolar electricity, and cold saline should be washed in time to cool down. After tumor resection, the bleeding of the tumor bed on the side of the brain stem can be stopped by pressing with cotton tablets. At the end of the operation, the cerebrospinal fluid circulation obstructed by the tumor should be restored, and the wound should be sutured layer by layer without dural suture.

radiotherapy

The treatment of medulloblastoma is mainly surgical resection and postoperative radiotherapy, and some cases may be supplemented with chemotherapy.

Due to the rapid growth of medulloblastoma, high cell division index, and its location close to the ventricle and subarachnoid space, there are many favorable conditions for radiotherapy. The initial medulloblastoma is sensitive to radiotherapy, but in order to prevent the tumor from shedding, planting and metastasis, the whole cerebrospinal cord radiotherapy is usually performed. The radiotherapy equipment changed from the early deep X-ray to 60 cobalt (60Co) and linear accelerator, and the radiotherapy dose increased, greatly improving the effect of radiotherapy. For the easy metastasis of medulloblastoma, radiotherapy should cover the whole central nervous system (whole brain, posterior cranial fossa and spinal cord).

How to do radiotherapy and chemotherapy after medulloblastoma?

For children older than 3 years, different doses of radiotherapy were used according to different risk, whole brain and whole spinal cord radiotherapy were used in the posterior cranial fossa, generally within 4 weeks after surgery.

After radiotherapy, blood routine and liver and kidney function should be reviewed, and chemotherapy can be started if the above laboratory indicators are normal. The time for blood routine to return to normal after radiotherapy in different patients is different, some 2 weeks to 4 weeks, some even 2 months. In general, chemotherapy can be started as long as blood routine is normal.

chemotherapy

Medulloblastoma is a malignant invasive embryonal tumor occurring in the cerebellum. It is most common in children and spreads easily through cerebrospinal fluid. Medulloblastoma accounts for about 20% of intracranial tumors and 40% of posterior cranial fossa tumors in children, and the peak age of onset is 6-9 years old. At least 75% of children with medulloblastoma originate in the vermis of the cerebellum and protrude into the fourth ventricle. With age, more and more cases involve the cerebellar hemisphere. Due to the easy spread and recurrence of medulloblastoma, chemotherapy is essential. The 5-year progression-free survival rate of surgery plus standard dose total central radiotherapy for standard critical myeloblastoma was 50%-65%, while the 5-year progression-free survival rate of surgery plus low dose total central radiotherapy plus chemotherapy for standard critical myeloblastoma was 81%.

clinical picture

The course of medulloblastoma is short and the disease progresses rapidly. The first symptoms are usually headache, vomiting, and drowsiness, resulting in the majority of children being misdiagnosed as gastrointestinal disorders. Gait instability, ataxia, neck stiffness, torticollis and other manifestations are also common. Tumor cells can spread to other parts of the central nervous system along the cerebrospinal fluid, and intramuscular metastasis can lead to nerve root involvement such as back and leg pain. Very few can develop distant metastases due to hematogenous spread, such as bone metastases can lead to bone pain.

Treatment method

1. Treatment of standard critical medulloblastoma: The conventional treatment of standard critical medulloblastoma is surgery + reduced dose radiotherapy (total central radiotherapy dose reduced from 36G y to 23.4G y)+ chemotherapy, with a 5-year progression-free survival rate of 81%. The 5-year progression-free survival (50%-65%) was significantly improved with surgery plus standard dose radiotherapy (total central 36G y) compared with no chemotherapy.

2. Treatment of high-risk medulloblastoma over 3 years old: The standard treatment for high-risk medulloblastoma over 3 years old is: surgery + standard dose radiotherapy + high-dose chemotherapy. The treatment strategies of high-risk and high-risk patients are different. If the treatment of high-risk medulloblastoma is followed, the 5-year survival rate of high-risk medulloblastoma is less than 55%.

3. Treatment of high-risk medulloblastoma under the age of three: Radiotherapy should be avoided and delayed due to the large damage to the brain tissue of these children. The 5-year survival rate of children with medulloblastoma younger than 3 years old can reach 66% with surgery and high-intensity chemotherapy.

4. Conducting clinical trials to explore new chemotherapy regimen.Clinical studies of optimized chemotherapy regimenes and new anticancer drugs are underway to try to improve survival in high-risk patients as well as patients with relapse.

5, medulloblastoma in which cases the first postoperative chemotherapy:

(1) Postoperative chemotherapy for medulloblastoma under three years of age was performed and radiotherapy was postponed.

(2) For some patients with medulloblastoma that has been widely spread at the time of diagnosis, chemotherapy can be performed for 2-4 cycles after surgery, followed by radiotherapy after tumor shrinkage and reduction, and chemotherapy can be continued after radiotherapy.

(3) Some medulloblastoma postoperative mutism, irritability, etc., can not cooperate with radiotherapy, chemotherapy can be first, and then radiotherapy after mutism, etc., continue to complete chemotherapy after radiotherapy.

⑷ Recurrent patients, especially those with multiple relapses.