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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.
Some benign tumors need no treatment; others may be removed if they cause problems such as seizures, discomfort or cosmetic concerns. Surgery is usually the most effective approach and is used to treat most benign tumors. In some case other treatments may be of use. Adenomas of the rectum may be treated with sclerotherapy, a treatment in which chemicals are used to shrink blood vessels in order to cut off the blood supply. Most benign tumors do not respond to chemotherapy or radiation therapy, although there are exceptions; benign intercranial tumors are sometimes treated with radiation therapy and chemotherapy under certain circumstances. Radiation can also be used to treat hemangiomas in the rectum. Benign skin tumors are usually surgically resected but other treatments such as cryotherapy, curettage, electrodesiccation, laser therapy, dermabrasion, chemical peels and topical medication are used.
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.
General treatment regimens have not changed much in the past 30 years, in part due to the lack of randomized clinical trials. Surgery is the treatment of choice if the tumor is determined to be resectable. Curettage is a commonly used technique. The situation is complicated in a patient with a pathological fracture. It may be best to immobilize the affected limb and wait for the fracture to heal before performing surgery.
Patients with tumors that are not amenable to surgery are treated with radiation therapy. However caution is employed since a majority of recurrent tumors with transformations to the malignant sarcoma phenotype have been in patients receiving radiotherapy for their primary benign lesion. Pharmacotherapy for GCTOB, includes bisphosphonates such as Zoledronate, which are thought to induce apoptosis in the MNGC fraction, preventing tumor-induced osteolysis. Indeed, "in vitro" studies have shown zolidronate to be effective in killing osteoclast-like cells. More recently, humanized monoclonal antibodies such as Denosumab targeting the RANK ligand have been employed in treatment of GCTOB in a phase II study. This is based on the notion that increased expression of RANK-ligands by stromal cells plays a role in tumor pathogenesis.
Overall, the mainstay of the treatment for salivary gland tumor is surgical resection. Needle biopsy is highly recommended prior to surgery to confirm the diagnosis. More detailed surgical technique and the support for additional adjuvant radiotherapy depends on whether the tumor is malignant or benign.
Surgical treatment of parotid gland tumors is sometimes difficult, partly because of the anatomical relationship of the facial nerve and the parotid lodge, but also through the increased potential for postoperative relapse. Thus, detection of early stages of a tumor of the parotid gland is extremely important in terms of prognosis after surgery.
Generally, benign tumors of the parotid gland are treated with superficial(Patey's operation) or total parotidectomy with the latter being the more commonly practiced due to high incidence of recurrence. The facial nerve should be preserved whenever possible. The benign tumors of the submandibular gland is treated by simple excision with preservation of mandibular branch of the trigeminal nerve, the hypoglossal nerve, and the lingual nerve. Other benign tumors of minor salivary glands are treated similarly.
Malignant salivary tumors usually require wide local resection of the primary tumor. However, if complete resection cannot be achieved, adjuvant radiotherapy should be added to improve local control. This surgical treatment has many sequellae such as cranial nerve damage, Frey's syndrome, cosmetic problems, etc.
Usually about 44% of the patients have a complete histologic removal of the tumor and this refers to the most significant survival rate.
There are three main treatments for Hürthle cell adenomas. Once the adenoma is detected most often the nodules removed to prevent the cells from later metastisizing. A total thyroidectomy is often performed, this results in a complete removal of the thyroid. Some patients may only have half of their thyroid removed, this is known as a thyroid lobectomy. Another treatment option includes pharmacological suppression of thyroid hormone. The thyroid gland is responsible for producing the thyroid hormones triiodothyronine (T3) and thyroxine (T4). Patients with suppressed thyroid function often require oral thyroid replacement (e.g. levothyroxine) in order to maintain normal thyroid hormone levels. The final treatment option is RAI abaltion (radioactive iodine ablation). This treatment option is used to destroy infected thyroid cells after total thyroidectomy. This treatment does not change prognosis of disease, but will diminish the recurrence rate. Also, Hürthle cells do not respond well to RAI. However, often doctors suggest this treatment to patients with Hürthle cell adenoma and Hürthle cell carcinoma because some Hürthle cells will respond and it will kill remaining tissue.
The primary method for treatment is surgical, not medical. Radiation and chemotherapy are not needed for benign lesions and are not effective for malignant lesions.
Benign granular cell tumors have a recurrence rate of 2% to 8% when resection margins are deemed clear of tumor infiltration. When the resection margins of a benign granular cell tumor are positive for tumor infiltration the recurrence rate is increased to 20%. Malignant lesions are aggressive and difficult to eradicate with surgery and have a recurrence rate of 32%.
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.
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 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.
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.
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 may include the following:
- Surgery with or without radiation
- Radiotherapy
Fast neutron therapy has been used successfully to treat salivary gland tumors, and has shown to be significantly more effective than photons in studies treating unresectable salivary gland tumors.
- Chemotherapy
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.
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.
Depending on the grade of the sarcoma, it is treated with surgery, chemotherapy and/or radiotherapy.
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.
Chemotherapy and radiotherapy are effective in some tumors (such as Ewing's sarcoma) but less so in others (such as chondrosarcoma).
There is a variety of chemotherapy treatment protocols for bone tumors. The protocol with the best reported survival in children and adults is an intra-arterial protocol where tumor response is tracked by serial arteriogram. When tumor response has reached >90% necrosis surgical intervention is planned.
One of the major concerns is bone density and bone loss. Non-hormonal bisphosphonates increase bone strength and are available as once-a-week prescription pills. Metastron also known as strontium-89 chloride is an intravenous medication given to help with the pain and can be given in three month intervals. Generic Strontium Chloride Sr-89 Injection UPS, manufactured by Bio-Nucleonics Inc., it is the generic version of Metastron. Astra zantec is currently under review as to the benefits in bone cancer.
Treatment usually consists of observation unless the patient has concern, there is pain, drainage, or other symptoms related to the lesion. Surgical removal of the affected gland would be recommended in those cases. Another treatment option would be aspiration, which can be repeated multiple times. This is commonly performed in those who are debilitated or in those whose benefit from surgery would be outweighed by the risks. Prognosis is usually good; rarely this condition may devolve into lymphoma, or could actually represent 'occult' lymphoma from the outset.
Ocular oncology is the branch of medicine dealing with tumors relating to the eye and its adnexa.
Ocular oncology takes into consideration that the primary requirement for patients is preservation of life by removal of the tumor, along with best efforts directed at preservation of useful vision, followed by cosmetic appearance. The treatment of ocular tumors is generally a multi-specialty effort, requiring coordination between the ophthalmologist, medical oncologist, radiation specialist, head & neck surgeon/ENT surgeon, pediatrician/internal medicine/hospitalist and a multidisciplinary team of support staff and nurses.