Tag Archives: Oncology

Radiotherapy

Definition:
Radiotherapy is a way of treating or managing cancer using radiation. It works by damaging cells in the area being treated. Normal cells are able to repair this damage, but cancer cells can’t and are destroyed.
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Radiation therapy is commonly applied to the cancerous tumor because of its ability to control cell growth. Ionizing radiation works by damaging the DNA of exposed tissue, furthermore, it is believed that cancerous cells may be more susceptible to death by this process as many have turned off their DNA repair machinery during the process of becoming cancerous. To spare normal tissues (such as skin or organs which radiation must pass through in order to treat the tumor), shaped radiation beams are aimed from several angles of exposure to intersect at the tumor, providing a much larger absorbed dose there than in the surrounding, healthy tissue. Besides the tumour itself, the radiation fields may also include the draining lymph nodes if they are clinically or radiologically involved with tumor, or if there is thought to be a risk of subclinical malignant spread. It is necessary to include a margin of normal tissue around the tumor to allow for uncertainties in daily set-up and internal tumor motion. These uncertainties can be caused by internal movement (for example, respiration and bladder filling) and movement of external skin marks relative to the tumor position.

Radiation oncology is the medical specialty concerned with prescribing radiation, and is distinct from radiology, the use of radiation in medical imaging and diagnosis). Radiation may be prescribed by a radiation oncologist with intent to cure (“curative”) or for adjuvant therapy. It may also be used as palliative treatment (where cure is not possible and the aim is for local disease control or symptomatic relief) or as therapeutic treatment (where the therapy has survival benefit and it can be curative). It is also common to combine radiation therapy with surgery, chemotherapy, hormone therapy, Immunotherapy or some mixture of the four. Most common cancer types can be treated with radiation therapy in some way. The precise treatment intent (curative, adjuvant, neoadjuvant, therapeutic, or palliative) will depend on the tumor type, location, and stage, as well as the general health of the patient. Total body irradiation (TBI) is a radiation therapy technique used to prepare the body to receive a bone marrow transplant. Brachytherapy, in which a radiation source is placed inside or next to the area requiring treatment, is another form of radiation therapy that minimizes exposure to healthy tissue during procedures to treat cancers of the breast, prostate and other organs.

Radiation therapy has several applications in non-malignant conditions, such as the treatment of trigeminal neuralgia, severe thyroid eye disease, pterygium, pigmented villonodular synovitis, and prevention of keloid scar growth, vascular restenosis , and heterotopic ossification. The use of radiation therapy in non-malignant conditions is limited partly by worries about the risk of radiation-induced cancers.

Method of radiotherapy
Radiotherapy can be given as teletherapy (also known as external beam radiotherapy), when a beam of radiation is aimed at the area to be treated from a machine located away from the patient.

Other forms of radiotherapy are high or low-dose brachytherapy, which involves a radioactive source being placed on or in a tumour.

Dose:
The amount of radiation used in photon radiation therapy is measured in gray (Gy), and varies depending on the type and stage of cancer being treated. For curative cases, the typical dose for a solid epithelial tumor ranges from 60 to 80 Gy, while lymphomas are treated with 20 to 40 Gy.

Preventative (adjuvant) doses are typically around 45 – 60 Gy in 1.8 – 2 Gy fractions (for Breast, Head, and Neck cancers.) Many other factors are considered by radiation oncologists when selecting a dose, including whether the patient is receiving chemotherapy, patient comorbidities, whether radiation therapy is being administered before or after surgery, and the degree of success of surgery.

Delivery parameters of a prescribed dose are determined during treatment planning (part of dosimetry). Treatment planning is generally performed on dedicated computers using specialized treatment planning software. Depending on the radiation delivery method, several angles or sources may be used to sum to the total necessary dose. The planner will try to design a plan that delivers a uniform prescription dose to the tumor and minimizes dose to surrounding healthy tissues.

Treatment planning
All patients who are to have radiotherapy need individually tailored treatment so it is given accurately. A lot of information is needed so the doctor can target the tumour while minimising damage to the healthy tissue. This is called treatment planning and there are a number of ways of doing this.

Simulator planning is done using a specialised x-ray machine that can do the same things as the treatment machines except deliver treatment. The simulator allows the doctor to carefully look at the area that needs treatment and plan it precisely. During the planning, the radiographer will draw some marks on the skin using a pen; when the doctor and radiographer are happy they have an accurate plan, the radiographer may need to make two to three permanent marks called tattoos. These tattoos are the size of a pinhead and are used to ensure the radiotherapy is given to exactly the right place.

ACQSIM planning is done using a scanner. Some patients may need to have an intravenous injection before the scan to show up the area to be treated better. The scan usually takes about 15 minutes and the information from the scan is used to produce a treatment map. Sometimes it’s necessary to take some x-rays and measurements to check the treatment map and this is done on the simulator.

What radiotherapy involves
When radiotherapy treatment is being given by external beam, it’s important the patient is in exactly the same position each time. The radiographers will often use pillows and wedges to make sure the patient is comfortable and in the correct position.

Patients having radiotherapy to the head or neck area may need to have a mould made to keep them in the right position. Moulds are made from clear Perspex after a plaster cast has been made of the head and neck. Once the Perspex mould has been made, the radiotherapy is planned while the patient is wearing the mould and marks are drawn on the mask instead of the skin.

Once the radiographers are happy that the patient is in the correct position they will leave the room to switch the treatment machine on. When the machine is on it makes a buzzing noise. The radiographers watch closely on a television screen. Treatment only lasts a few minutes and does not hurt.

Side effect of radiotherapy
Side effects are different depending on the part of the body being treated. Most side effects are temporary but some may continue for weeks or months after treatment is finished. They include:

•Hair loss (alopecia)
•Cerebral oedema (excess fluid accumulating in the brain) can cause changes in mental state, restlessness, irritability, impaired pupil reactions, headache, increase in blood pressure, decrease in pulse and respiration, and nausea
•Dry or sore mouth or throat, changes in taste sensation, skin thickening
•Inflammation of the gullet, indigestion, nausea, lung inflammation
•Nausea and vomiting, diarrhoea, cystitis
•Sexual dysfunction. In males treatment of the abdomen area can cause impotence, sterility. In females it can cause sterility, loss of sexual desire. Irradiation of the pelvis may cause tightening of the vagina, loss of vaginal lubrication, inflammation or ulceration of the vagina. Some women may find intercourse painful
•Treatment of red bone marrow may cause infection and impaired healing, anaemia, increased tiredness, bruising and bleeding

As well as treating cancer the radiotherapy temporarily damages the outer layers of skin. During treatment the skin cannot repair itself as it normally would and it can become sore. But once treatment has finished the skin generally recovers quite quickly – usually within a month. The level of reaction can depend on your skin type, the type and number of treatments you have, and how you would normally react to the sun.

Skin side effects usually happen later on in the course of radiotherapy treatment or sometimes a few weeks after treatment has finished. Many patients do not have any skin changes at all. Skin care advice will be given to the patients by the staff treating them.

A common side effect of radiotherapy is tiredness and fatigue, which often prevents patients from doing normal everyday activities. Fatigue and tiredness are normal results of having radiotherapy and begin in the first week of treatment, reaching a peak after two weeks of treatment and gradually disappearing a few weeks after treatment has finished.

Radiation therapy accidents:
There are rigorous procedures in place to minimise the risk of accidental overexposure of radiation therapy to patients. However, mistakes do occasionally occur; for example, the radiation therapy machine Therac-25 was responsible for at least six accidents between 1985 and 1987, where patients were given up to one hundred times the intended dose; two people were killed directly by the radiation overdoses. From 2005 to 2010, a hospital in Missouri overexposed 76 patients (most with brain cancer) during a five-year period because new radiation equipment had been set up incorrectly.  Although medical errors are exceptionally rare, radiation oncologists, medical physicists and other members of the radiation therapy treatment team are working to eliminate them. ASTRO has launched a safety initiative called Target Safely  that, among other things, aims to record errors nationwide so that doctors can learn from each and every mistake and prevent them from happening. ASTRO also publishes a list of questions for patients to ask their doctors about radiation safety to ensure every treatment is as safe as possible.

Disclaimer: This information is not meant to be a substitute for professional medical advise or help. It is always best to consult with a Physician about serious health concerns. This information is in no way intended to diagnose or prescribe remedies.This is purely for educational purpose.

Resources:
http://en.wikipedia.org/wiki/Radiation_therapy
http://www.bbc.co.uk/health/physical_health/conditions/in_depth/cancer/carecancer_radio.shtml
http://www.allvitalpoints.com/2010/how-radiotherapy-is-performed/

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New CyberKnife Technology to Treat Cancer

Introduction:
Breakthroughs in imaging and robotics technology have been combined in the revolutionary new Cyberknife radiosurgery system.CyberKnife technology involves no cuts or incisions whatsoever. It destroys diseased tissue by precisely focusing multiple beams of high-energy radiation on the tumor site. It is specifically designed for treating the most complex and difficult tumorscancers of the lung, spine, pancreas or brain.

Sub-millimeter accuracy:
The sub-millimeter accuracy of the CyberKnife system is unmatched. Combining advanced robotic technology and an innovative image guidance system, the CyberKnife can treat tumors in or near sensitive structures such as the spine, brain and lungs.

It is the only radiosurgery system in the world with real-time tumor tracking. The CyberKnife moves and adapts to patient movement, including breathing. Because the CyberKnife doesn’t require an external frame, it can be used outside the cranial area.

How does it work?
The CyberKnife radiosurgery system uses a linear accelerator (linac) to produce and deliver focused beams of radiation to the tumor site. Using image guidance cameras, the exact shape and position of the tumor is identified. The linac, which is attached to a robotic arm, delivers multiple beams of radiation that converge at the tumor site. The tumor receives a concentrated dose of radiation while minimizing exposure to surrounding normal tissue.

The CyberKnife system is the first device to enable full-body dynamic radiosurgery and makes possible effective new treatments in clinical areas such as spine, lung and pancreas.

CyberKnife Machine

Key benefits:-
Treatment planning
The CyberKnife system provides multiple planning and delivery options. It is the only radiosurgery system with the capability to provide non-isocentric treatment planning.

No immobilization
Unlike conventional radiosurgery systems, the CyberKnife system does not require the use of a head or body frame to immobilize the patient. CyberKnife’s intelligent robotics detect and correct for any patient movement and/or respiration.

Localization:
With robotic image guidance technology, the CyberKnife system is the only radiosurgery system that tracks patient and lesion positions during the entire treatment process. This portion of CyberKnife’s intelligent robotics system continuously scans and detects any patient or lesion movement and makes any necessary corrections. The CyberKnife’s Synchrony™ technology tracks respiratory motion and adjusts for patient breathing.

Treatment delivery
The CyberKnife system’s robotic arm provides multiple targeting nodes and adjusts to compensate for any patient movement detected by the robotic guidance technology. This ensures sub-millimeter accuracy with each procedure.

For more information or to request a second opinion please click here or call the St. Luke‘s second opinion program at 888-649-6892.

What to expect:-
Initial visit
At your convenience, an outpatient planning session will be conducted. During the visit, a custom mask or body mold designed to inhibit movement during CyberKnife treatment will be created. The molding process is simple and painless.

A CT scan and possibly an MRI are performed to confirm the exact size, shape and location of your tumor, along with surrounding vital structures. All are used for treatment planning purposes.

Patients undergoing extracranial (non-head) treatment also require the implant of small metal markers (fiducials) prior to the initial set-up. This procedure is also done on an outpatient basis.

Treatment visits
On the day of your treatment, you will be asked to wear comfortable clothing and no jewelry. Because CyberKnife treatment is painless, no anesthesia is required. You will lie on a treatment table and will be fitted with the mask or body mold created earlier.

During your treatment, you will be asked to lie still. You will be awake throughout the entire procedure, which typically lasts 30 to 90 minutes. The image guidance system periodically takes x-ray images and compares them to data from the CT scan to ensure that the treatment is accurately targeted.

Treatment sessions are performed on an outpatient basis. In most cases, you can resume normal activities immediately upon leaving the hospital.

Follow-up visits
As with any radiosurgery or radiation therapy procedure, follow-up imaging and physician consultation are required to monitor your progress.

For more information or to request a 2nd opinion please click here or call the St. Luke’s 2nd opinion program at 888-649-6892.

Click to Learn more about the CyberKnife procedure

Click to see:->

Treat cancer with Cyberknife
Emerging Treatments for Cancer Using CyberKnife Technology

CyberKnife: Technology to Transform Lives

Now, CyberKnife technology to treat cancer in India

Sources:
http://www.aurorahealthcare.org/services/cancer/treatments/radiationoncology/cyberknife/index.asp

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Effective Treatment for Neuroblastoma

Experts have claimed that they have discovered an effective treatment for deadly cancer — neuroblastoma — by applying new science with a 40-year-old known drug.

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Michelle Haber, a molecular and cellular biologist in Australia, said laboratory trials with mice genetically programmed to develop neuroblastoma — a solid tumour that spreads rapidly through the body — showed the drug, DFMO, delayed the development of tumours or prevented them forming in the first place.

By combining DFMO with conventional anti-cancer drugs such as cisplatin, that was then used to treat mice with neuroblastoma, the tumours were reduced, took longer to return and some tumours never came back, according to a report published in The Australian.

Haber, executive director of Sydney-based Children’s Cancer Institute Australia for Medical Research, said, “The mice were cured. That’s something you virtually never see in aggressive neuroblastoma.”

Luciano Dalla-Pozza, head of oncology at Children’s Hospital in Sydney welcomed the series of genetic and animal experiments Haber’s team had conducted.

“If the trial was opened now, I’d unhesitantly look at enrolling patients in it,” Dalla-Pozza said.

While roughly 75 per cent of children diagnosed with other cancers survive, only 50 per cent of those diagnosed with neuroblastoma survive. Two-thirds of youngsters get an aggressive form of neuroblastoma that kills more than 80 per cent of them within a year.

Haber said discussions were under way with Sydney Children’s Hospital and the Children’s Hospital of Philadelphia for trials of combination therapy with children who had relapsed from neuroblastoma.
“For me that’s incredibly exciting,” Haber said.

Sources: The Times Of India

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Protein Compels Cancer Cells to Death

A protein that inhibits ovarian cancer growth does so by partly forcing the cancerous cells to self-destruct, according to the latest research.

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The Texas Univeristy (TU) team that carried out the study also found that expression of PEA-15, a protein, is an independent indicator of a woman’s prospects for surviving ovarian cancer, said study co-author Naoto T Ueno, associate professor of breast medical oncology.

An analysis of ovarian tumours in 395 women showed those with high expression of the PEA-15 survived for 50.2 months, compared to 33.5 months for women with low protein levels.

Ovarian cancer kills about 15,000 women in US alone every year. It is notoriously hard to diagnose in its early stages, when it is also most optimal time to treat, according to a TU release.

“These findings provide a foundation for developing a PEA-15 targeted approach for ovarian cancer and for clarifying whether this protein is a novel biomarker that can predict patient outcomes,” Ueno said.

Sources:The report appeared in Saturday’s issue of Cancer Research.

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Acupuncture Beats Drug to Treat Hot Flashes

acupuncture

Acupuncture works as well as Effexor, a drug commonly used to combat hot flashes and other menopausal symptoms that can accompany breast cancer treatment.

In fact, the benefits of acupuncture last longer than the effects of Effexor, and without any bad side effects. After 12 weeks of treatment, symptoms were reduced for 15 additional weeks for women who had undergone acupuncture, compared with just two weeks for those who had taken Effexor.

Not only were no bad side effects associated with acupuncture, women who underwent the treatment reported increased energy and overall sense of well-being. Those taking Effexor reported side effects including nausea, headache, difficulty sleeping, dizziness, increased blood pressure, fatigue and anxiety.

Sources:
  • American Society for Therapeutic Radiology and Oncology Meeting September 21-25, 2008 Boston, MA
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