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
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.
The mainstay of treatment is surgical excision. Two adjuvant therapeutic strategies are Stereotactic surgery (SRS) and fractionated convention radiotherapy (FCRT). Both are highly effective means of treatment.
Chemotherapy is typically limited to patients with recurrent central neurocytoma. The course of chemotherapy used for CNC is one of two platinum-based regimes. The two regimes are:
- Carboplatin + VP-16 + ifosfamide
- cisplatin + VP-16 + cyclophosphamide
Because chemotherapy is used in rare cases there is still information to be gathered as to the efficacy of chemotherapy to treat benign CNC. Therefore, recommendations must be viewed as limited and preliminary.
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.
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.
The objective of irradiation is to halt the growth of the acoustic neuroma tumour, it does not excise it from the body, as the term 'radiosurgery' or 'gammaknife' implies. Radiosurgery is only suitable for small to medum size tumors.
Most treatments involve some combination of surgery and chemotherapy. Treatment with cisplatin, etoposide, and bleomycin has been described.
Before modern chemotherapy, this type of neoplasm was highly lethal, but the prognosis has significantly improved since.
When endodermal sinus tumors are treated promptly with surgery and chemotherapy, fatal outcomes are exceedingly rare.
Acoustic neuromas are managed by either surgery, radiation therapy, or observation with regular MRI scanning. With treatment, the likelihood of hearing preservation varies inversely with the size of the tumor; for large tumors, preservation of hearing is rare. Because acoustic neurmas, meningiomas and most other CPA tumors are benign, slow growing or non-growing, and non-invasive, observation is a viable management option.
Treatment for cystic hygroma involves the removal of the abnormal tissue; however complete removal may be impossible without removing other normal areas. Surgical removal of the tumor is the typical treatment provided, with the understanding that additional removal procedures will most likely be required as the lymphangioma grows. Most patients need at least two procedures done for the removal process to be achieved. Recurrence is possible but unlikely for those lesions able to be removed completely via excisional surgery. Radiotherapy and chemical cauteries are not as effective with the lymphangioma than they are with the hemangioma. Draining lymphangiomas of fluid provides only temporary relief, so they are removed surgically. Cystic Hygroma can be treated with OK432 (Picibanil).
The least invasive and most effective form of treatment is now performed by interventional radiologists. A sclerosing agent, such as 1% or 3% sodium tetradecyl sulfate, doxycycline, or ethanol, may be directly injected into a lymphocele. "All sclerosing agents are thought to work by ablating the endothelial cells of the disrupted lymphatics feeding into the lymphocele."
Lymphangioma circumscription can be healed when treated with a flashlamp pulsed dye laser, although this can cause port-wine stains and other vascular lesions.
There are several different surgical techniques for the removal of acoustic neuroma. The choice of approach is determined by size of the tumour, hearing capability, and general clinical condition of the patient.
- The retrosigmoid approach offers some opportunity for the retention of hearing.
- The translabyrinthine approach will sacrifice hearing on that side, but will usually spare the facial nerve. Post-operative cerebrospinal fluid leaks are more common.
- The middle fossa approach is preferred for small tumours, and offers the highest probability of retention of hearing and vestibular function.
- Less invasive endoscopic techniques have been done outside of the United States for some time. Recovery times are reported to be faster. However, this technique is not yet mainstream among surgeons in the US.
Larger tumors can be treated by either the translabyrinthine approach or the retrosigmoid approach, depending upon the experience of the surgical team. With large tumors, the chance of hearing preservation is small with any approach. When hearing is already poor, the translabyrinthine approach may be used for even small tumors. Small, lateralized tumours in patients with good hearing should have the middle fossa approach. When the location of the tumour is more medial a retrosigmoid approach may be better.
Auditory canal decompression is another surgical technique that can prolong usable hearing when a vestibular schwannoma has grown too large to remove without damage to the cochlear nerve. In the IAC (internal auditory canal) decompression, a middle fossa approach is employed to expose the bony roof of the IAC without any attempt to remove the tumor. The bone overlying the acoustic nerve is removed, allowing the tumour to expand upward into the middle cranial fossa. In this way, pressure on the cochlear nerve is relieved, reducing the risk of further hearing loss from direct compression or obstruction of vascular supply to the nerve.
Radiosurgery is a conservative alternative to cranial base or other intracranial surgery. With conformal radiosurgical techniques, therapeutic radiation focused on the tumour, sparing exposure to surrounding normal tissues. Although radiosurgery can seldom completely destroy a tumor, it can often arrest its growth or reduce its size. While radiation is less immediately damaging than conventional surgery, it incurs a higher risk of subsequent malignant change in the irradiated tissues, and this risk in higher in NF2 than in sporadic (non-NF2) lesions.
The tumor must be removed with as complete a surgical excision as possible. In nearly all cases, the ossicular chain must be included if recurrences are to be avoided. Due to the anatomic site of involvement, facial nerve paralysis and/or paresthesias may be seen or develop; this is probably due to mass effect rather than nerve invasion. In a few cases, reconstructive surgery may be required. Since this is a benign tumor, no radiation is required. Patients experience an excellent long term outcome, although recurrences can be seen (up to 15%), especially if the ossicular chain is not removed. Although controversial, metastases are not seen in this tumor. There are reports of disease in the neck lymph nodes, but these patients have also had other diseases or multiple surgeries, such that it may represent iatrogenic disease.
These lesions rarely require surgery unless they are symptomatic or the diagnosis is in question. Since these lesions do not have malignant potential, long-term observation is unnecessary. Surgery can include the removal of the head of the pancreas (a pancreaticoduodenectomy), removal of the body and tail of the pancreas (a distal pancreatectomy), or rarely removal of the entire pancreas (a total pancreatectomy). In selected cases the surgery can be performed using minimally invasive techniques such as laparoscopy.
A 2009 clinical trial at Massachusetts General Hospital used the cancer drug Bevacizumab (commercial name: Avastin) to treat 10 patients with neurofibromatosis type II. The result was published in "The New England Journal of Medicine". Of the ten patients treated with bevacizumab, tumours shrank in 9 of them, with the median best response rate of 26%. Hearing improved in some of the patients, but improvements were not strongly correlated with tumour shrinkage. Bevacizumab works by cutting the blood supply to the tumours and thus depriving them of their growth vector. Side effects during the study included alanine aminotransferase, proteinuria, and hypertension (elevated blood pressure) among others. A separate trial, published in "The Neuro-oncology Journal", show 40% tumour reduction in the two patients with NF2, along with significant hearing improvement.
Overall the researchers believed that bevacizumab showed clinically significant effects on NF-2 patients. However, more research is needed before the full effects of bevacizumab can be established in NF-2 patients.
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.
Depending on the grade of the sarcoma, it is treated with surgery, chemotherapy and/or radiotherapy.
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.
MASC is currently treated as a low-grade (i.e. Grade 1) carcinoma with an overall favorable prognosis. These cases are treated by complete surgical excision. However, the tumor does have the potential to recur locally and/or spread beyond surgically dissectible margins as well as metastasize to regional lymph nodes and distant tissues, particularly in tumors with histological features indicating a high cell growth rate potential. One study found lymph node metastasis in 5 of 34 MASC patients at initial surgery for the disease; these cases, when evidencing no further spread of disease, may be treated with radiation therapy. The treatment of cases with disease spreading beyond regional lymph nodes has been variable, ranging from simple excision to radical resections accompanied by adjuvant radiotherapy and/or chemotherapy, depending on the location of disease. Mean disease-free survival for MASC patients has been reported to be 92 months in one study.
The tyrosine kinase activity of NTRK3 as well as the ETV6-NTRK3 protein is inhibited by certain tyrosine kinase inhibitory drugs such as Entrectinib and LOXO-101; this offers a potential medical intervention method using these drugs to treat aggressive MASC disease. Indeed, one patient with extensive head and neck MASC disease obtained an 89% fall in tumor size when treated with entrectinib. This suppression lasted only 7 months due to the tumor's acquirement of a mutation in the "ETV6-NTRK3" gene. The newly mutated gene encoded an entrectinib-reisistant "ETV6-NTRK3" protein. Treatment of aggressive forms of MASC with NTRK3-inhibiting tyrosine kinase inhibiting drugs, perhaps with switching to another type of tyrosine kinase inhibitor drug if the tumor acquires resistance to the initial drug, is under study.STARTRK-2
The prognosis for lymphangioma circumscriptum and cavernous lymphangioma is generally excellent. This condition is associated with minor bleeding, recurrent cellulitis, and lymph fluid leakage. Two cases of lymphangiosarcoma arising from lymphangioma circumscriptum have been reported; however, in both of the patients, the preexisting lesion was exposed to extensive radiation therapy.
In cystic hygroma, large cysts can cause dysphagia, respiratory problems, and serious infection if they involve the neck. Patients with cystic hygroma should receive cytogenetic analysis to determine if they have chromosomal abnormalities, and parents should receive genetic counseling because this condition can recur in subsequent pregnancies.
Complications after surgical removal of cystic hygroma include damage to the structures in the neck, infection, and return of the cystic hygroma.
A baby with a prenatally diagnosed cystic hygroma should be delivered in a major medical center equipped to deal with neonatal complications, such as a neonatal intensive care unit. An obstetrician usually decides the method of delivery. If the cystic hygroma is large, a cesarean section may be performed. After birth, infants with a persistent cystic hygroma must be monitored for airway obstruction. A thin needle may be used to reduce the volume of the cystic hygroma to prevent facial deformities and airway obstruction. Close observation of the baby by a neonatologist after birth is recommended. If resolution of the cystic hygroma does not occur before birth, a pediatric surgeon should be consulted.
Cystic hygromas that develop in the third trimester, after thirty weeks gestation, or in the postnatal period are usually not associated with chromosome abnormalities. There is a chance of recurrence after surgical removal of the cystic hygroma. The chance of recurrence depends on the extent of the cystic hygroma and whether its wall was able to be completely removed.
Treatments for removal of cystic hygroma are surgery or sclerosing agents which include:
- Bleomycin
- Doxycycline
- Ethanol (pure)
- Picibanil (OK-432)
- Sodium tetradecyl sulfate
Because of the rarity of these tumors, there is still a lot of unknown information. There are many case studies that have been reported on patients who have been diagnosed with this specific type of tumor. Most of the above information comes from the findings resulting from case studies.
Since Papillary Tumors of the Pineal Region were first described in 2003, there have been seventy cases published in the English literature. Since there is such a small number of cases that have been reported, the treatment guidelines have not been established. A larger number of cases that contain a longer clinical follow-up are needed to optimize the management of patients with this rare disease.
Even though there is a general consensus on the morphology and the immunohistochemical characteristics that is required for the diagnosis, the histological grading criteria have yet to be fully defined and its biological behavior appears to be variable. This specific type of tumor appears to have a high potential for local recurrence with a high tumor bed recurrence rate during the five years after the initial surgery. This suggests the need for a tumor bed boost radiotherapy after surgical resection.
As stated above, the specific treatment guidelines have not yet been established, however, gross total resection of the tumor has been the only clinical factor associated overall and progression-free survival. The value of radiotherapy as well as chemotherapy on disease progression will need to be investigated in future trials. With this information, it will provide important insight into long-term management and may further our understanding of the histologic features of this tumor.
A subependymoma is a type of brain tumor; specifically, it is a rare form of ependymal tumor.
The prognosis for a subependymoma is better than for most ependymal tumors, and is considered a grade I tumor in the World Health Organization (WHO) classification.
They are classically found within the fourth ventricle, typically have a well demarcated interface to normal tissue and do not usually extend into the brain parenchyma, like ependymomas often do.
Treatment of THS includes immunosuppressives such as corticosteroids (often prednisolone) or steroid-sparing agents (such as methotrexate or azathioprine).
Radiotherapy has also been proposed.
The word hemangiopericytoma comes from the ancient Greek words: (combining form of Ancient Greek αἷμα, haîma, “blood”), (means blood vessel), , (prefix meaning “about” or “around”, “enclosing” or “surrounding”, and “near”, appearing in loanwords from Greek; and -cytoma (refers to the cells surrounding the blood vessel walls).
Neuroendocrine adenoma of the middle ear (NAME) is a tumor which arises from a specific anatomic site: middle ear. NAME is a benign glandular neoplasm of middle ear showing histologic and immunohistochemical neuroendocrine and mucin-secreting differentiation (biphasic or dual differentiation).