Made by DATEXIS (Data Science and Text-based Information Systems) at Beuth University of Applied Sciences Berlin
Deep Learning Technology: Sebastian Arnold, Betty van Aken, Paul Grundmann, Felix A. Gers and Alexander Löser. Learning Contextualized Document Representations for Healthcare Answer Retrieval. The Web Conference 2020 (WWW'20)
Funded by The Federal Ministry for Economic Affairs and Energy; Grant: 01MD19013D, Smart-MD Project, Digital Technologies
Surgery is often the treatment of choice. Total resection (removal of the tumor) is often possible. However, the best choice of treatment will depend on many individual factors, including:
- The patient's medical history and overall health condition
- The type, location, and size of the tumor
- The patient's age
- How well the patient tolerates specific medications, procedures, or therapy
- How slowly or quickly the tumor is expected to progress
If surgery is performed and the tumor is completely resected, further treatment may not be required. The patient will, however, need repeated MRIs to monitor for tumor re-growth.
For tumors that recur, another surgical resection might be attempted. For tumors that could not be completely removed, radiation therapy may also be recommended. Also called radiotherapy, this treatment uses high-energy radiation to damage or kill cancer cells and shrink tumors.
Symptoms of PXA may disappear, or improve progressively, after treatment. For example:
- Symptoms related to increased pressure in the brain often disappear after surgical removal of the tumor.
- Effects like seizures might progressively improve as recovery progresses.
- Steroid treatment is often used to control tissue swelling that may occur before and after surgery.
Radiation therapy may include photon-beam or proton-beam treatment, or fractionated external beam radiation. Radiosurgery may be used in lieu of surgery in small tumors located away from critical structures. Fractionated external-beam radiation also can be used as primary treatment for tumors that are surgically unresectable or, for patients who are inoperable for medical reasons.
Radiation therapy often is considered for WHO grade I meningiomas after subtotal (incomplete) tumor resections. The clinical decision to irradiate after a subtotal resection is somewhat controversial, as no class I randomized, controlled trials exist on the subject. Numerous retrospective studies, however, have suggested strongly that the addition of postoperative radiation to incomplete resections improves both progression-free survival (i.e. prevents tumor recurrence) and improves overall survival.
In the case of a grade III meningioma, the current standard of care involves postoperative radiation treatment regardless of the degree of surgical resection. This is due to the proportionally higher rate of local recurrence for these higher-grade tumors. Grade II tumors may behave variably and there is no standard of whether to give radiotherapy following a gross total resection. Subtotally resected grade II tumors should be radiated.
Likely, current chemotherapies are not effective. Antiprogestin agents have been used, but with variable results. A 2007 study of whether hydroxyurea has the capacity to shrink unresectable or recurrent meningiomas is being further evaluated.
Even after surgery, an oligoastrocytoma will often recur. The treatment for a recurring brain tumor may include surgical resection, chemo and radiation therapy. Survival time of this brain tumor varies - younger age and low-grade initial diagnosis are factors in improved survival time.
Various management options exist depending on the severity of symptoms and their effect on the patient. The main management options are: observation, craniotomy for microsurgical resection, neuroendoscopic removal, stereotactic drainage, and cerebrospinal fluid diversion with bilateral ventriculoperitoneal shunting placement.
Multiple studies have been found on how to remove a colloid cyst. One is an endoscopic removal. To remove the cyst, make a small incision. The endoscope is inserted into the brain and then moved toward the tumor in the ventricular compartment. The tumor is hit with an electric current. The interior of the cyst is removed followed by the cyst wall. The electric current is then used to kill the remaining pieces of the cyst. This whole process, including closing of the incision and removal of the scope is completed within 45 minutes to an hour. The patients are able to leave the hospital after 1 or 2 days. A case was done with the absence of ventriculomegaly that has been contraindication in an endoscopic removal. The study found that with normal-sized ventricles are not a contraindication. They actually have comparable or less complication rates. Another study experimented with a smaller retractor tube, 12 mm instead of 16–22 mm. The study found that using a 12 mm tube on a 10 mm colloid cyst. The surgery was successful in removing the cyst with a smaller retractor tube for resection while minimizing injury. The surgery had potential for improving outcomes.
Neuroendoscopic third ventriculostomy during surgery can be used to prevent further hydrocephalus post op. This removes the need for insertion of bilateral shunts.
Chemotherapy is the preferred secondary treatment after resection. The treatment kills astroblastoma cells left behind after surgery and induces a non-dividing, benign state for remaining tumor cells. Normally, chemotherapy is not recommended until the second required resection, implying that the astroblastoma is a high-grade tumor continuing to recur every few months. A standard chemotherapy protocol starts with two rounds of nimustine hydrochoride (ACNU), etoposide, vincristine, and interferon-beta. The patient undergoes a strict drug regimen until another surgery is required. By the third surgery, should recurrence in the astroblastoma occur, a six-round program of ifosfamide, cisplatin, and etoposide will "shock" the patient's system to the point where recurrence halts. Unfortunately, chemotherapy may not always be successful with patients requiring further resection of the tumor, since the tumor cell begins to show superior vasculature and a strong likelihood of compromising a patient's well-being. Oral ingestion of temozolomide for at-home bedside use may be preferred by the patient.
Although surgery is the treatment of choice, it must be preceded by imaging studies to exclude an intracranial connection. Potential complications include meningitis and a cerebrospinal fluid leak. Recurrences or more correctly persistence may be seen in up to 30% of patients if not completely excised.
The primary and most desired course of action described in medical literature is surgical removal (resection) via craniotomy. Minimally invasive techniques are becoming the dominant trend in neurosurgical oncology. The prime remediating objective of surgery is to remove as many tumor cells as possible, with complete removal being the best outcome and cytoreduction ("debulking") of the tumor otherwise. In some cases access to the tumor is impossible and impedes or prohibits surgery.
Many meningiomas, with the exception of some tumors located at the skull base, can be successfully removed surgically.
Most pituitary adenomas can be removed surgically, often using a minimally invasive approach through the nasal cavity and skull base (trans-nasal, trans-sphenoidal approach). Large pituitary adenomas require a craniotomy (opening of the skull) for their removal. Radiotherapy, including stereotactic approaches, is reserved for inoperable cases.
Several current research studies aim to improve the surgical removal of brain tumors by labeling tumor cells with 5-aminolevulinic acid that causes them to fluoresce. Postoperative radiotherapy and chemotherapy are integral parts of the therapeutic standard for malignant tumors. Radiotherapy may also be administered in cases of "low-grade" gliomas when a significant tumor burden reduction could not be achieved surgically.
Multiple metastatic tumors are generally treated with radiotherapy and chemotherapy rather than surgery and the prognosis in such cases is determined by the primary tumor, and is generally poor.
When a brain tumor is diagnosed, a medical team will be formed to assess the treatment options presented by the leading surgeon to the patient and his/her family. Given the location of primary solid neoplasms of the brain in most cases a "do-nothing" option is usually not presented. Neurosurgeons take the time to observe the evolution of the neoplasm before proposing a management plan to the patient and his/her relatives. These various types of treatment are available depending on neoplasm type and location and may be combined to give the best chances of survival:
- Surgery: complete or partial resection of the tumor with the objective of removing as many tumor cells as possible.
- Radiotherapy: the most commonly used treatment for brain tumors; the tumor is irradiated with beta, x rays or gamma rays.
- Chemotherapy: is a treatment option for cancer, however, it is not always used to treat brain tumors as the blood-brain barrier can prevent some drugs from reaching the cancerous cells.
- A variety of experimental therapies are available through clinical trials.
Survival rates in primary brain tumors depend on the type of tumor, age, functional status of the patient, the extent of surgical tumor removal and other factors specific to each case.
Depending on the grade of the sarcoma, it is treated with surgery, chemotherapy and/or radiotherapy.
Radiation therapy selectively kills astroblastoma cells while leaving surrounding normal brain tissue unharmed. The use of radiation therapy after an astroblastoma excision has variable results. Conventional external beam radiation has both positive and negative effects on patients, but it is not recommended at this point to treat all types. All in all, the radiosensitivity of astroblastoma to therapy remains unclear, since some research advocate its effectiveness while others diminish the effects. Future studies must be done on patients with both total excision and sub-excision of the tumor to accurately assess whether radiation benefits patients under different circumstances.
For recurrent high-grade glioblastoma, recent studies have taken advantage of angiogenic blockers such as bevacizumab in combination with conventional chemotherapy, with encouraging results.
Supportive treatment focuses on relieving symptoms and improving the patient’s
neurologic function. The primary supportive agents are anticonvulsants and
corticosteroids.
- Historically, around 90% of patients with glioblastoma underwent anticonvulsant treatment, although it has been estimated that only approximately 40% of patients required this treatment. Recently, it has been recommended that neurosurgeons not administer anticonvulsants prophylactically, and should wait until a seizure occurs before prescribing this medication. Those receiving phenytoin concurrent with radiation may have serious skin reactions such as erythema multiforme and Stevens–Johnson syndrome.
- Corticosteroids, usually dexamethasone given 4 to 8 mg every 4 to 6 h, can reduce peritumoral edema (through rearrangement of the blood–brain barrier), diminishing mass effect and lowering intracranial pressure, with a decrease in headache or drowsiness.
Treatment for brain gliomas depends on the location, the cell type, and the grade of malignancy. Often, treatment is a combined approach, using surgery, radiation therapy, and chemotherapy. The radiation therapy is in the form of external beam radiation or the stereotactic approach using radiosurgery. Spinal cord tumors can be treated by surgery and radiation. Temozolomide, a chemotherapeutic drug, is able to cross the blood–brain barrier effectively and is currently being used in therapy for high-grade tumors.
If resected, the surgeon will remove as much of this tumor as possible, without disturbing eloquent regions of the brain (speech/motor cortex) and other critical brain structure. Thereafter, treatment may include chemotherapy and radiation therapy of doses and types ranging based upon the patient's needs. Subsequent MRI examination are often necessary to monitor the resection cavity.
The best-studied medical treatment for intracranial hypertension is acetazolamide (Diamox), which acts by inhibiting the enzyme carbonic anhydrase, and it reduces CSF production by six to 57 percent. It can cause the symptoms of hypokalemia (low blood potassium levels), which include muscle weakness and tingling in the fingers. Acetazolamide cannot be used in pregnancy, since it has been shown to cause embryonic abnormalities in animal studies. Also, in human beings it has been shown to cause metabolic acidosis as well as disruptions in the blood electrolyte levels of newborn babies. The diuretic furosemide is sometimes used for a treatment if acetazolamide is not tolerated, but this drug sometimes has little effect on the ICP.
Various analgesics (painkillers) may be used in controlling the headaches of intracranial hypertension. In addition to conventional agents such as paracetamol, a low dose of the antidepressant amitriptyline or the anticonvulsant topiramate have shown some additional benefit for pain relief.
The use of steroids in the attempt to reduce the ICP is controversial. These may be used in severe papilledema, but otherwise their use is discouraged.
The standard initial treatment is to remove as much of the tumor as possible without worsening neurologic deficits. Radiation therapy has been shown to prolong survival and is a standard component of treatment. There is no proven benefit to adjuvant chemotherapy or supplementing other treatments for this kind of tumor. Although temozolomide is effective for treating recurrent anaplastic astrocytoma, its role as an adjuvant to radiation therapy has not been fully tested.
Quality of life after treatment depends heavily on the area of the brain that housed the tumor. In many cases, patients with anaplastic astrocytoma may experience various types of paralysis, speech impediments, difficulties planning and skewed sensory perception. Most cases of paralysis and speech difficulties can be rehabilitated with speech, occupational, physical, and vision therapy.
Treatment of rhabdomyosarcoma is a multidisciplinary practice involving the use of surgery, chemotherapy, radiation, and possibly immunotherapy. Surgery is generally the first step in a combined therapeutic approach. Resectability varies depending on tumor site, and RMS often presents in sites that don't allow for full surgical resection without significant morbidity and loss of function. Less than 20% of RMS tumors are fully resected with negative margins. Fortunately, rhabdomyosarcomas are highly chemosensitive, with approximately 80% of cases responding to chemotherapy. In fact, multi-agent chemotherapy is indicated for all patients with rhabdomyosarcoma. Before the use of adjuvant and neoadjuvant therapy involving chemotherapeutic agents, treatment solely by surgical means had a survival rate of <20%. Modern survival rates with adjuvant therapy are approximately 60–70%.
There are two main methods of chemotherapy treatment for RMS. There is the VAC regimen, consisting of vincristin, actinomyocin D, and cyclophosphamide, and the IVA regimen, consisting of ifosfamide, vincristin, and actinomyocin D. These drugs are administered in 9–15 cycles depending on the staging of the disease and other therapies used. Other drug and therapy combinations may also show additional benefit. Addition of doxorubicin and cisplatin to the VAC regimen was shown to increase survival rates of patients with alveolar-type, early-stage RMS in IRS study III, and this same addition improved survival rates and doubled bladder salvage rates in patients with stage III RMS of the bladder.
Radiation therapy, which kill cancer cells with focused doses of radiation, is often indicated in the treatment of rhabdomyosarcoma, and the exclusion of this treatment from disease management has been shown to increase recurrence rates. Radiation therapy is used when resecting the entirety of the tumor would involve disfigurement or loss of important organs (eye, bladder, etc.). Generally, in any case where a lack of complete resection is suspected, radiation therapy is indicated. Administration is usually following 6–12 weeks of chemotherapy if tumor cells are still present. The exception to this schedule is the presence of parameningeal tumors that have invaded the brain, spinal cord, or skull. In these cases radiation treatment is started immediately. In some cases, special radiation treatment may be required. Brachytherapy, or the placement of small, radioactive “seeds” directly inside the tumor or cancer site, is often indicated in children with tumors of sensitive areas such as the testicles, bladder, or vagina. This reduces scattering and the degree of late toxicity following dosing. Radiation therapy is more often indicated in higher stage classifications.
Immunotherapy is a more recent treatment modality that is still in development. This method involves recruiting and training the patient's immune system to target the cancer cells. This can be accomplished through administering small molecules designed to pull immune cells towards the tumors, taking immune cells pulled from the patient and training to attack tumors through presentation with tumor antigen, or other experimental methods. A specific example here would be presenting some of the patient's dendritic cells, which direct the immune system to foreign cells, with the PAX3-FKHR fusion protein in order to focus the patient's immune system to the malignant RMS cells. All cancers, including rhabdomyosarcoma, could potentially benefit from this new, immune-based approach.
The prognosis for gliomatosis cerebri is generally poor. Surgery is not practical considering the extent of the disease, standard chemotherapy (nitrosourea) has been unsuccessful, and while brain irradiation can stabilize or improve neurologic function in some patients, its impact on survival has yet to be proven.
In 2014, Weill Cornell Brain and Spine Center launched an international registry for Gliomatosis Cerebri, where tissue samples can be stored for genomic study.
Most studies show no benefit from the addition of chemotherapy. However, a large clinical trial of 575 participants randomized to standard radiation versus radiation plus temozolomide chemotherapy showed that the group receiving temozolomide survived a median of 14.6 months as opposed to 12.1 months for the group receiving radiation alone. This treatment regime is now standard for most cases of glioblastoma where the person is not enrolled in a clinical trial. Temozolomide seems to work by sensitizing the tumor cells to radiation.
High doses of temozolomide in high-grade gliomas yield low toxicity, but the results are comparable to the standard doses.
Antiangiogenic therapy with medications such as bevacizumab control symptoms but do not affect overall survival.
Germinomas, like several other types of germ cell tumor, are sensitive to both chemotherapy and radiotherapy. For this reason, treatment with these methods can offer excellent chances of longterm survival, even cure.
Although chemotherapy can shrink germinomas, it is not generally recommended alone unless there are contraindications to radiation. In a study in the early 1990s, carboplatinum, etoposide and bleomycin were given to 45 germinoma patients, and about half the patients relapsed. Most of these relapsed patients were then recovered with radiation or additional chemotherapy.
Oligodendrogliomas are generally felt to be incurable using current treatments. However compared to the more common astrocytomas, they are slowly growing with prolonged survival. In one series, median survival times for oligodendrogliomas were 11.6 years for grade II and 3.5 years for grade III.
However, such figures can be misleading since they do not factor in the types of treatment nor the genetic signature of the tumors. A recent study analyzed survival based on chromosomal deletions and the effects of radiation or chemotherapy as treatment, with the following results (both low-grade and anaplastic oligodendrogliomas): 1p/19q deletion with radiation = 121 months (mean), 1p/19q deletion with chemotherapy = over 160 months (mean not yet reached), no 1p/19q deletion with radiation = 58 months (mean), and no 1p/19q deletion with chemotherapy = 75 months (mean). Another study divided anaplastic oligodendrogliomas into the following four clinically relevant groups of histology with the following results: combined 1p/19q loss = median survival was >123 months (not yet reached), 1p loss only = median survival was 71 months, 1p intact with TP53 mutation = median survival 71 months, and 1p intact with no TP53 mutation = median survival was 16 months.
Because of the indolent nature of these tumors and the potential morbidity associated with neurosurgery, chemotherapy and radiation therapy, most neurooncologists will initially pursue a course of watchful waiting and treat patients symptomatically. Symptomatic treatment often includes the use of anticonvulsants for seizures and steroids for brain swelling. PCV chemotherapy (Procarbazine, CCNU and Vincristine) has been shown to be effective and was the most commonly used chemotherapy regimen used for treating anaplastic oligodendrogliomas, but is now being superseded by a newer drug: Temozolomide. Temozolomide is a common chemotherapeutic drug to which oligodendrogliomas appear to be quite sensitive. It is often used as a first line therapy, especially because of its relatively mild side effects when compared to other chemotherapeutic drugs.
Nevertheless, a retrospective study on 1054 patients with anaplastic oligodendroglioma, presented during the 2009 ASCO Annual Meeting, suggests that PCV therapy may be superior in efficacy to the newer temozolomide therapy. Median time to progression for patients with 1p19q co-deletion was longer following PCV alone (7.6 years) than with temozolomide alone (3.3 years); median overall survival was also longer with PCV treatment versus temozolomide treatment (not reached, vs. 7.1 years).
The standard dosing schedule of temozolomide is 5 consecutive days of daily dosing during 28-day cycles. However, different dosing schedules may produce better results, such as continuous daily dosing using lower amounts of drug (e.g. 21-day dosing during 28-day cycles). As an example of an altered dosing schedule, promising results have been shown using lower daily doses on each day for 7 weeks, followed by a 4-week off periods. Regarding the duration of dosing, for oligodendrogliomas the duration prescribed by oncologists varies considerably and seems to range from 6 cycles to over 32 cycles (i.e. over 3 years). In one study, researchers compared patients who received temozolomide for at least 12 months on the 5/28 day cycle, dividing such patients into two groups: "short term" patients receiving temozolomide for 12-18 cycles and those "long term" patients receiving 19 or more cycles (range was 19 to 32 cycles). Researchers found that there was a statistically significant advantage for "long term" treatment (median progression free survival for "short term" patients was 95 weeks (follow up of 73 weeks), but for "long term" patients the median progression free survival was not yet reached (follow up of 134 weeks)).
Because of their diffusely infiltrating nature, oligodendrogliomas cannot be completely resected and are not curable by surgical excision. If the tumor mass compresses adjacent brain structures, a neurosurgeon will typically remove as much of the tumor as he or she can without damaging other critical, healthy brain structures. Surgery may be followed up by chemotherapy, radiation, or a mix of both, but recent studies suggest that radiation does not improve overall survival (even when age, clinical data, histological grading, and type of surgery are considered). However, a recent long-term study does affirm that radiation combined with adjuvant chemotherapy is significantly more efficacious for anaplastic oligodendroglioma patients with 1p 19q co-deleted tumors and has become the new standard of care. However, it is possible that radiotherapy may prolong the overall time to progression for non-deleted tumors.
Oligodendrogliomas, like all other infiltrating gliomas, have a very high (almost uniform) rate of recurrence and gradually increase in grade over time. Recurrent tumors are generally treated with more aggressive chemotherapy and radiation therapy. Recently, stereotactic surgery has proven successful in treating small tumors that have been diagnosed early.
Long-term survival is reported in a minority of patients. With aggressive treatment and close monitoring, it is possible to outlive the typical life expectancies for both low grade and high grade oligodendrogliomas. Westergaard's
study (1997) showed that patients younger than 20 years had a median survival of 17.5 years. Another study shows a 34% survival rate after 20 years. However, as discussed above, such figures can be misleading since they do not factor in the types of treatment nor the genetic signature of the tumors. Additionally, such historic data loses significance due to the relatively long survival of patients (compared to other types of brain tumors) and the introduction of newer treatment options over time.
The first step in symptom control is drainage of cerebrospinal fluid by lumbar puncture. If necessary, this may be performed at the same time as a diagnostic LP (such as done in search of a CSF infection). In some cases, this is sufficient to control the symptoms, and no further treatment is needed.
The procedure can be repeated if necessary, but this is generally taken as a clue that additional treatments may be required to control the symptoms and preserve vision. Repeated lumbar punctures are regarded as unpleasant by patients, and they present a danger of introducing spinal infections if done too often. Repeated lumbar punctures are sometimes needed to control the ICP urgently if the patient's vision deteriorates rapidly.