Radiation therapy is used in the curative treatment of medulloblastoma, germinoma and lymphoma tumors. For a number of patients this may be sufficient to cure their cancer.
There is a major risk of spinal fluid metastases in the central nervous system with medulloblastoma or germinoma tumors. Radiation therapy to the entire central nervous system with a subsequent boost to the primary area is usually required for curing the patient. Radiation therapy to the ventricle system supplied with a boost to the main tumor is sufficient for germinomas.
Postoperative radiation therapy, limited to the tumor area with 2–3 cm margins, is routine for high-grade malignant glioblastoma gliomas (grade IV) and for anaplastic gliomas (grade III). It can also destroy infiltrating cancer cells around the main tumor. Radiation therapy will have a life-extending, but generally not a curative, effect on such conditions.
Radiation therapy limited to the tumor area will relieve the symptoms for low-grade (grade 1–2) gliomas, but will probably not have a life-extending effect. Indications for radiation therapy for low-grade gliomas must, therefore, be individually evaluated.
Radiation therapy limited to the tumor area will often stop the growth of local, aggressive, inoperable hypophyseal adenomas and meningiomas. These tumors will most often persist after external radiation therapy, but this is rarely of clinical significance provided that further tumor growth is prevented.
In the case of brain metastasis, often the entire brain is subjected to radiation. However, stereotactic treatment - either as the only modality or as a boost to macroscopic metastasis - is an alternative for conditions with a maximum of 3 metastases and where the largest single metastasis has a diameter of < 3 cm.
For malignant infiltrating tumors (grade III–IV gliomas), the addition of local radiation therapy can destroy infiltrating cancer cells around the main tumor and thereby extend the patient's life.
An individually adapted target volume and dosage is administered. CT and MRI-based dosage planning, risk assessment with regard to normal tissue structures, as well as informing the patient of the value of radiation therapy when weighed against any potential risk for delayed damage to normal tissue must all be included as routine preparation for radiation therapy.
If the patient cannot be operated on, either for medical reasons or due to the location of the tumor - close to or in important nerve centers in the brain, then radiation therapy as the sole treatment method may be an alternative.
- Intracranial tumors that are difficult to access for surgery
- Other intracranial tumors
- Tumor reduction, local tumor control or cure.