The vast Universe has many mysteries. The curiosity of humans led to the discovery of telescope, radio waves. The marvelous calculation and curiosity leading to the moment of discovery with the quickening of the pulse as the apple drops from the tree. The man jumps up from a bathtub; the tricky equation balances itself.
The antithesis—that is hardly recorded: the discovery of the failure. It is a moment that a scientist often confronts alone when a wrong diagnosis or a denied treatment leads to the killing of a creative sufferer.
In the times of a novel virus let's talk about a novel discovery.
Dr. Robert Wilson described the basis for using proton beam therapy for the treatment of cancer as early as 1946. The early proton facilities were mainly physics research laboratories that seldom treated patients with cancer. We now have several dedicated proton facilities for the treatment of cancer.
First, Wilhelm Conrad Roentgen discovered X-rays using a cathode ray tube (CRT) in 1895. Then, Antoine Henri Becquerel detected radioactivity in 1896 using a photographic plate and uranium salts of phosphorescent materials. This was followed by the identification of electrons for the first time using a CRT in 1897 by Sir J. J. Thomson. Two years later, in 1899, Ernest Rutherford discovered α-particles in the radiation emitted from uranium salts, following which, in 1909, Geiger and Marsden observed that an α-particle deflects at an angle of more than 90°when it strikes a gold foil. The following year, Geiger showed that the largest possible deflection of a particle passing through a thin gold foil was less than 1°. It was very difficult to understand that the large deflection angle of the α-particles after they struck thin gold foil was a result of the sum of multiple small deflections. In the same year, Sir J. J. Thomson proposed a theory to explain this strange behavior of α-particles. His atomic structure model suggested that an atom consists of a number of negative charges accompanied by an equal number of positive charges uniformly distributed in a sphere. Using this model, he hypothesized that the large deflections would not take place without the positively- and uniformly-charged sphere being very much smaller than the size of the whole atom. Building on the knowledge gained from experimental work and theories, Ernest Rutherford suggested a simple atomic structure model that was able to explain the large deflection behavior. He described that, according to his model, an atom contains negative charges uniformly distributed in a sphere surrounding positive charges at its central point. He determined that the large deflection must have been caused by a single collision. This idea successfully explained how α-particles exhibited large deflections while passing through thin gold foils. This came to be known as the “Rutherford Scattering Experiment,” which led to the discovery of the atomic nucleus in 1911. During that year, Rutherford published a new atomic model showing that an atom consists of electrons orbiting around a very small nucleus in which most of the atomic mass and charge is concentrated. He needed eight more years to uncover the detailed structure of the atomic nucleus.
Rutherford was the first researcher to propose the development of a particle accelerator to enable further research regarding the atomic nucleus. This was the beginning of research into nuclear and high energy physics that would lead to the application of particle accelerators to the medical field years later.
Dr. Robert Wilson described the basis for using proton beam therapy for the treatment of cancer as early as 1946. The early proton facilities were mainly physics research laboratories that seldom treated patients with cancer. We now have several dedicated proton facilities for the treatment of cancer. There are several current clinical applications for proton beam therapy including prostate, lung, pediatric, central nervous system cancers, and several other malignancies.
High energy proton beams with features such as deep penetration, little scatter, and Bragg peak effect attracted physicians. With those distinctive features, it became possible to deliver a dose of radiation to selected areas in the body.
Too much radiation kills healthy tissue. In other words, the beneficial effects of radiation therapy occur when a lethal dose of radiation is deposited in the area of cancer and the harmful effects of radiation therapy occur when healthy tissue is inadvertently irradiated while trying to treat cancer.
The electrons can be made to strike a tungsten target within the head of the accelerator to create a beam of photons (or “X-rays”). These X-ray beams are then directed at the site of cancer. Photons have no charge or mass and can be regarded as small packets of energy. Photons deposit their energy along the entire path that they travel through the body. Therefore, a beam of X-rays irradiates not only the area of cancer but also the healthy tissue that the beam encounters on its way towards the tumor and beyond the tumor. X-rays used for treating cancer usually do not stop within the body. X-rays travel right through you. On the other hand, proton beam therapy is delivered by larger, much more expensive accelerators called cyclotrons and synchrotrons.
Standard radiation therapy has evolved and improved over the years and is effective in controlling many cancers. However, because X-ray beams are composed of primary photons and secondary electrons, they deposit their energy along the path of the beam, to the targeted tumor and beyond, and deliver radiation to healthy tissues before and after the tumor site. This radiation “exit dose” may cause health issues later because it can damage the normal tissue or organs near the tumor or area of concern.
The advantage of proton therapy (also called proton beam therapy) is that the physician can control where the proton releases the bulk of its cancer-fighting energy. As the protons move through the body, they slow down and interact with electrons, and release energy. The point where the highest energy release occurs is the “Bragg peak.” A physician can designate the Bragg peak’s location, causing the most damage to the targeted tumor cells. A proton beam conforms to the shape and depth of a tumor while sparing healthy tissues and organs.
By contrast, proton therapy delivers a beam of proton particles that stops at the tumor, so it’s less likely to damage nearby healthy tissues. Some experts believe that proton therapy is safer than traditional radiation, but there is limited research comparing the two treatments.
~ says National Cancer Institute
On the other hand, proton beam therapy is delivered by larger, much more expensive accelerators called cyclotrons and synchrotrons.
A proton beam directed at a tumor travels in a straight trajectory towards its target, gives off most of its energy at a defined depth called the Bragg peak, and then stops. While X-rays often deposit more energy within the healthy tissues of the body than within cancer.
Compared with X-rays, proton beam therapy has the ability to improve cure rates by increasing the dose delivered to the tumor and simultaneously reduce side effects by decreasing the dose to surrounding healthy tissue.
A method of delivering therapeutic radiation to the target volume located at a predetermined depth from the skin with an array of mini beams at the surface in an amount spatially arranged and sized to maintain a tissue-sparing effect from the skin to a proximal size of the target volume and to merge into a target beam into the proximal side of the target volume. A gap between the parallel spatially distinct mini beams at the surface such that the array merges into a solid beam at a predetermined beam energy and across all energies for Bragg-peak spreading at the proximal side of the target volume.
The brain is another obvious site where there are advantages to using proton beam therapy compared with photons. The brain parenchyma, brainstem, optic structures, and hypothalamic–pituitary axis are examples of normal tissues that are potentially subject to the harmful effects of irradiation.Although CNS hemangioblastomas are often defining lesions in VHL patients, supratentorial and retrobulbar hemangioblastomas in particular are rare.4,5 In a study of 160 VHL patients with CNS involvement examined at the National Institutes of Health (NIH), 655 hemangioblastomas were identified by magnetic resonance imaging (MRI), with 250 occurring in the cerebellum, 64 in the brainstem, 331 in the spinal cord, and only 10 in the supratentorial region.5 Isolated case reports also describe retrobulbar optic nerve hemangioblastomas along the intraorbital optic nerve, intracanalicular optic nerve, intracranial prechiasmal optic nerve, and optic chiasm. The chiasmal lesions can present with a bitemporal hemianopsia.15 These tumors have been reported to invade and destroy optic nerve tissue.8 Patients may present with vision loss, visual field (VF) defects, exophthalmos, optic nerve pallor, and diminished color vision. Intraoperatively, the tumors appear as a solid yellow, red, or reddish-brown mass. Characteristically, the tumor does not originate from the optic nerve dural sheath. Previously resected lesions have been found to lack a capsule and be unattached to the dura. At the NIH, over 300 patients with VHL are observed routinely at the National Eye Institute (NEI) and Surgical Neurology Branch in an effort to understand the natural history of this genetic disease. This collaboration has resulted in the identification of the following 9 cases of hemangioblastomas affecting the anterior visual pathway (prevalence rate, 3%).
The rise in popularity of proton therapy is continuing across the globe. It is estimated that more than patients suffering from a variety of cancers, such as prostate cancer, brain tumors, etc. have already been successfully treated using this method. As of August 2020, there are over 89 particle therapy facilities worldwide, with at least 41 others under construction. As of August 2020, there are 34 operational proton therapy centers in the United States. As of the end of 2015 more than 165,000 patients had been treated worldwide.
Proton Accelerators Protons injected into accelerators are produced by stripping hydrogen atoms of their electrons. These free protons are accelerated by electric fields to the desired energy.
Hence, only proton beam therapy can deal with my countless leptomeningeal hemangioblastomas.
One of the key components in cancer treatment is finding the best treatment option that can achieve the highest clinical results. Proton therapy reduces overall toxicity, improves quality of life during and after treatment and increases the long-term survival rates.
Proton therapy also may be used to treat these cancers:
Central nervous system cancers, including chordoma, chondrosarcoma, and malignant meningioma
Eye cancer, including uveal melanoma or choroidal melanoma
Head and neck cancers, including nasal cavity and paranasal sinus cancer and some nasopharyngeal cancers
Lung cancer
Liver cancer
Prostate cancer
Spinal and pelvic sarcomas, which are cancers that occur in the soft-tissue and bone
Noncancerous brain tumors
Proton vs Photon positivity vs negativity. Knowledge expands life and its quality.
“It's easy to feel hopeful on a beautiful day like today, but there will be dark days ahead of us too. There will be days where you feel all alone, and that's when hope is needed most. No matter how buried it gets, or how lost you feel, you must promise me that you will hold on to hope. Keep it alive. We have to be greater than what we suffer.”
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