Radiation Therapy

Radiation therapy, RT, has been used as a cancer treatment modality since the late nineteenth century, and advancements in technology have improved its ability to focus on treating tumors while reducing its side effects and the potential damage to normal tissues and organs.

Since the 1980s, radiation therapy has become much more prominent as a therapeutic modality for cancer. Specifically, because of technological improvements in producing tumor-focused computer delivery systems, compact linear accelerators to generate particles, and radiation oncology specialists devoted to directing the specialized team needed for planning and administering treatment, there is a differentiation between radiation oncologists whose expertise is in cancer treatment, while conventional radiology physicians provide their diagnostic expertise to uncover diseases.

Introduction

Radiation therapy directs energy particles moving in the form of waves that can be differentiated according to their specific frequencies and wavelengths. There is nonionizing radiation, which means that it lacks the energy to remove an atom or electron, which consists of long waves and low frequencies, such as microwaves, cell phones, and radio waves, and visible light, which are believed by some to not cause tissue damage. The other type is ionizing radiation, which is high-frequency and low-wavelength radiation that is capable of being accelerated, causing the ejection of electrons, called ionization. It is capable of producing tissue injury and damage to cells, DNA, and other molecules. Examples would be X-rays and ultraviolet waves, gamma rays used for sterilization and cancer treatments, CT scanners and X-rays, nuclear blast particles, and naturally occurring radon and cosmic rays.

The measurement of radiation used in treatment is based on the energy transfer into tissue. The gray (Gy) is the standard unit of ionizing radiation per dose. In cancer radiation, a single treatment ranges from 1.8 -2 Gy, with a total accumulated dose of approximately 50-60 Gy. Generally, the total amount is given in small fractionated doses of the total until the calculated effective dose needed for a specific cancer is achieved. However, there are current protocols that use higher single doses more frequently to achieve the same total accumulated dose but with a reduced number of visits.

There is another radiation measure called the Sievert, which is a measurement of environmental exposure that is used to define the potential biological harm from radiation. In the general public, this

exposure / year is very very small, approximately 6.2mSV, while medical radiation personnel are allowed 20uSV/year, with a 50uSV maximum in a year. These numbers monitor exposure amounts and are calculated to prevent excessive exposure.

Examples of patient exposure include chest x-ray 20uSV, a mammogram 600uSV, and a whole body CT 20,000uSV, which demonstrates the need for prudence and judgement when exposing people to radiologic imaging.

Mechanisms of Action

Radiation therapies primarily use photons, which are the basic units of light and electromagnetic radiation. The intention of radiation in cancer therapy is to deliver energy to a specific target area, damaging cancer cell DNA, preventing replication and repair, and resulting in death. And while normal and cancer cells both sustain radiation damage from treatment, normal cells have more robust inherent self-restorative mechanisms for DNA damage, which cancer cells lack.

Treatment Navigation

The decisions involved in planning radiation treatments are based on balancing the necessary dosage needed to destroy the cancer while limiting significant injury to normal tissues to reduce acute and potentially avoid long-term effects.

A team of experts is needed to coordinate the overall plan for each individual.

The medical dosimetrist designs, calculates, and measures the safe and effective amount of radiation needed for that tumor type.

The radiation physicist accurately determines the target area and the protection needed for the surrounding healthy tissue, and calibrates the radiation software.
The radiation oncologist is the commander of the team, working to coordinate all the participants by designing each individual protocol, managing patient consults, and communicating the plan to the patient while monitoring and adjusting treatment to achieve optimum effect and minimize side effects.

Choosing A Radiation Oncologist

The selection of your radiation oncologist requires that you understand the procedure protocol planned.

Questions that should be considered:

The training, experience, and years in practice of your practitioner.
Is your specific cancer an area of expertise? Many radiation oncologists are generalists and, while well-trained, may have limited experience with your type of cancer.
Interview the person who will treat you, assess your comfort level with their communications, and interview more than one if you need to.
Complications and side effects are essential to know. Ask what common ones occur acutely and which can appear late or after treatment is complete.
What treatment interventions are available?
What percentage of success from treatment can be realistically expected?

The Types of Radiation

External Beam Radiation (EBRT)

This is radiation therapy directed from outside the body at the cancer. It commonly uses high-energy X-rays but can use other types of radiation, like protons or electrons, which are artificially generated by a small linear accelerator, and directed and aimed at the targeted cancer area. Programmed computer software.

Treatment requires preparatory accuracy. Before treatment, the original detailed radiologic images are often matched with real-time images, which are fed into the specialized computer program to develop each individual's plan. The size, shape, angles, and density of the tumor configuration are determined, and the patient is then positioned in a posture that allows the beam accessibility from multiple angles.

Once the total dose is determined, it is divided into small fractions and administered daily until the total dose is completed, allowing normal tissues time to initiate repair between treatments.

Not all tumors receive the same amount of radiation. Lymphomas are very sensitive and require less dosage, while sarcoma and melanoma cancers require higher doses as they are more radiation resistant.

The goal of RT is to incorporate treatments that are able to maximize effect and minimize tissue injury and organ damage.

The timing of each treatment is short, generally in and out of the room in 15 minutes. External beam radiation over the last decade has become integrated as a primary treatment modality in distinct stages of breast and prostate cancer. For example:

In breast cancer, earlier treatment protocols were to perform a radical mastectomy, removing the breast, nodes, and chest muscles, which was severely disfiguring and severely limited shoulder movement. This has been replaced by the modified radical mastectomy, which is the removal of the breast itself. Currently, in earlier disease stages, 1 and 2, it is common to see breast conserving surgery, a lumpectomy only, along with radiation, which is shown to yield similar ten-year survival as the modified surgical mastectomy.
In prostate cancer, a patient who is at high risk for complications due to other significant medical problems, treatment with high-dose radiation combined with androgen deprivation therapy has been shown to be equivalent to radical prostate surgery by posing potentially lower risks with faster recovery and better quality of life.
Radiation treatment is being used for many solid tumors, including the central nervous system, lung, GI- primarily rectal and anal cancers, and studies also show that adding RT in a primary supportive role with other systemic treatments can be equivalent to radical surgical treatments in vulnerable areas such as the throat and laryngeal cancers and sarcomas. But breast and prostate are its most common uses.

Advanced Techniques Using Computer Technology for External Beam Radiation

Intensity Modulated Radiation Therapy, IMRT: It is a computer-controlled beam that has varied intensities across the tumor field.
Image Guided Radiation Therapy, IGRT: A scan is done before each treatment to reassess the position of the tumor and make adaptations to the beam.
3D Conformal Radiation Therapy,3DCRT: The computer shapes the beam to the precise 3D shape of the tumor.
Volumetric Modulated Arc Therapy, VMAT: The radiation is administered by a machine that revolves around the patient in a 3D image.
Brachytherapy: This form of radiation therapy involves the placement of a radiation source inside the body, next to the cancer, offering effects from a short distance to the target with less exposure to surrounding tissue. It is used primarily in prostate, gynecologic, and breast cancers.

Prostate Cancer

In Prostate cancer, brachytherapy is used in one of two ways: Low dose rate (LDR) and High dose rate (HDR. It offers a much shorter time frame of treatment compared to external beam radiation, which uses low radiation fractions administered over a number of weeks.

Low-dose rate Radiation is an option in localized low-risk prostate cancer in patients without existing urinary issues. Using guided images, the radiation source is inserted, commonly using transrectal ultrasound, as a single treatment where multiple radioactive seeds are permanently implanted and will emit radiation for several months.

High Dose Rate Radiation is commonly used in prostate cancer combined with EBRT, external beam radiation, as an augmentation radiation in situations where there is a high risk of spread. A transperineal catheter guide is inserted and loaded with the isotope and given in 1-2 doses over a day or a day and a half. It is commonly administered in a hospital setting, and upon completion, the isotope and catheter are removed.

Concerns using this method are often technique issues, as an experienced oncologist is essential, as the insertion needs to be precise to achieve correct placement and effects.

Regardless, with brachytherapy, there are concerns of risks to injury to the bladder, urethra, and rectum based on their proximity to the radiation source.

Gynecologic Radiation with Brachytherapy

This form of radiation therapy is utilized in vaginal, cervical, and uterine cancers, before or after surgery, alone or in combination with external beam radiation. A radiation source is placed, using special instruments, in the vagina and uterus, next to or into the cancer to allow a high dose of radiation to reach the tumor while attempting to minimize exposure to healthy tissues.

Breast Cancer

Following breast conservation surgery, a lumpectomy, one recommendation is for brachytherapy or internal radiation in early-stage disease. It has been shown to reduce the risk of locoregional recurrence, along with improving breast cancer and overall survival under specific conditions.

It is a complex topic that requires each patient to discuss the risks/benefits with their oncology team.

Types of Therapies

Particle Therapy

Particle beam therapy is a form of external beam radiation using Protons as the source. It allows radiation to be delivered in a focused manner and with a depth of energy that treats the tumor but has less effect on normal tissues. The expense of generating the particles and housing the necessary equipment is prohibitive, but it has been used in sensitive spine and brain cancers in children, where it has been shown to be effective and works better than external beam radiation. It is used in prostate cancer primarily, but also other solid tumors, but fails to demonstrate advantages over conventional EMRT.

Stereotactic Radiation Therapy Techniques

This form of radiation administers a full course of focused tumor therapy in a few or a limited number of treatments. It uses high-resolution imaging to assess the tumor configuration and size, as well as the adjacent normal structures, which then require special techniques to immobilize and mark the treatment area to avoid damaging normal tissues and structures.

Stereotactic Radio Surgery is a technique that utilizes a single fractionated treatment to structures within the brain or spinal cord.

Stereotactic Body Radiation gives the total amount of radiation in 2-5 fractions to treat the brain and spinal cord, but is also used for the lung, liver, pancreas, prostate, and head and neck, where, in external beam radiation, the full dose is given in small amounts over days or weeks. Total Body Irradiation (TBI) uses X-ray radiation, generally in combination with chemotherapy, for leukemias and lymphomas when a blood stem cell transplant is planned. It kills cancer cells throughout the body, decreases immune system protection to prevent rejection of a donor's stem cells, and destroys marrow cells to allow the new transplanted stem cells space to replicate and restore.

Targeted Radionucleotide Therapy

Elements in nature contain a balanced number of protons and neutrons. Some forms have an unequal number of particles and are unstable. In an attempt to stabilize, they emit isotopes or radioactive particles that occur naturally in nature or are created in the lab.

In cancer treatment, specific radioisotopes are used.

In thyroid cancer, iodine, the I-131 isotope, accumulates in the thyroid, which uses iodine to make thyroid hormone and kills thyroid cancer cells.
The radioisotope radium 223 accumulates specifically in bone and emits radiation, which is used to treat bone metastasis.
Using a monoclonal antibody, a form of man-made antibody, radiation can be linked to it, and in treatment, a receptor on the cancer cell that binds with the monoclonal antibody allows radiation to reach the cancer cell to destroy it.

Avoidance of Sugar during Radiation Therapy

Before and during radiation, avoiding sugar can improve its effectiveness significantly. A low glycemic diet implies eating foods that have less of an impact on the elevation of the blood sugar. They tend to be digested more slowly and create fewer peaks of blood sugar.

High sugar loads increase IGF-1, an insulin-like growth factor, which suppresses programmed cancer cell death, which is induced by radiation.

The Low-Glycemic Diet Includes:

Fruits and vegetables offer a combination of minerals, antioxidants, vitamins, fiber, and flavors.

High fiber fruits, apples, pears, and berries, as well as non-starchy veggies, lettuce and other leafy greens, broccoli, cauliflower, onions, zucchini, and beans.

Nuts and seeds are rich in essential fatty acids, micronutrients, and protein coming from almonds, walnuts, chia, flax, and pumpkin seeds, pecans, and walnuts.
Plant oils, limited amounts of olive, avocado, and coconut
Whole grains are composed of 3 parts: the kernel, the bran, and the endosperm, which are minimally processed so that the nutrients are retained. These include brown rice, oats, quinoa, whole wheat, and barley( check if you can eat gluten)
Legumes, which are seeds grown within pods, include beans, peas, lentils, peanuts, soybeans, chickpeas, and carob.
Avoid sweet drinks like soda, sweet tea, bottled juices, and energy drinks, and increase the amount of water and herbal teas.
Avoid refined sugars found in cakes, cookies, processed cereals, bread products, especially white bread. Pasta can raise blood sugar, as can rice. Rice that is cooked and then frozen for a meal, when thawed, becomes much lower in sugar and higher in fiber.

Radiation Side Effects

Acute Toxicity is the result of the inflammation generated from the radiation. Common symptoms are generally associated with the system involved

Localized swelling and edema
Upper abdominal area: nausea and vomiting
The head and neck: mouth sores
Larynx and pharyngeal area: inflamed throat
Esophagus: ulcerations
Pelvis: abdominal pain, cystitis, difficulty urinating

Commonly, these issues improve and resolve with time, upon completion of radiation.

There are also multiple integrative supportive approaches for reducing these types of symptoms and their impact.

The late Toxicity from radiation treatment is a double-edged sword, getting the benefits for cancer treatment but having the potential, especially years to decades later, of causing damage as a result.

Late Toxicity is dependent upon multiple variables:

The proximity of sensitive tissues and organs to the area being treated.

And the specific treatment area involved.

The total amount of radiation that will be needed for treatment is based on the volume of tissue, tumor size, and the sensitivity of the specific cancer.
The addition of overlapping similar side effects that occur from surgery or chemotherapy.
Long-term effects can result in chronic damage, causing the development of scar tissue or fibrosis, sometimes seen months later.
Damage occurs to what is called the extracellular matrix, which is considered the supportive tissues throughout the body that encompass our cells.
Pelvic irradiation in the childbearing years can damage the ovaries or testes, affecting fertility and/or causing low sex hormone levels.
Late effects in younger patients can be the development of another cancer, often decades later.

Late Toxicity From Radiation in the Upper Chest Region

Scarring of connective tissue from localized radiation treatment occurring in the heart can be associated with breast, esophageal, and lung cancer treatment, and lymphomas with lymph node radiation in the chest. The symptoms can develop years to decades after treatment.

Fibrosis involving the heart can affect such functions as coronary artery blood supply to the heart, cardiomyopathy causing diminished heart contraction, valvular disease, or electrical conduction problems. These complications are rare, and the data are based on studies from decades ago. Today's techniques use lower radiation doses and different techniques that can minimize these adverse effects.

Associated factors that increase these risks are hypertension, obesity, smoking, and high cholesterol. There are also chemotherapies, anthracycline drugs, like doxorubicin/adriamycin and trastuzumab, Herceptin, that pose cardiac risks independent of the radiation and are important additional risk factors.

The necessity of continued refinements in chest radiation therapies to reduce the occurrence of long-term cardiac risks is being stressed as survival in these diseases, especially lung cancer, continues to increase, potentially impacting quality of life and lifespan.

Lymphedema in Breast Cancer

In breast cancer, removal of the axillary nodes or regional axillary radiation for early breast cancer can cause fibrosis or scarring of tissues, which blocks the flow of protein-rich lymphatic fluid, which can result in swelling of the upper arm, lower arm, or hand. Prior to modern surgical techniques, the incidence of lymphedema was 22%. With less invasive surgery and the use of the sentinel node biopsy, rather than automatically removing the axillary lymph nodes, the risk has been reduced.
In addition, there are earlier follow-ups and evaluations, as well as the use of interventional therapies such as manual lymph drainage, compression garments, physical therapy exercises, and skin care to prevent injury. There are also pneumatic compression pumps that inflate and deflate to move fluid using a sleeve.
A small study using hyperbaric oxygen showed improvement in lymphedema. Therapy involves using a pressurized chamber of 100% oxygen.

The results showed 20% had reduced and 25% improved lymphedema after several months.

Another study showed a 38% reduction in hand edema.

Late Toxicity from Head and Neck Radiation

Based on the anatomic area, there are local issues that can occur, including,

Salivary gland damage and permanent dry mouth, dental caries and jaw bone damage, skin fibrosis, trismus of the jaw muscle, causing clinching with a decreased ability to fully open the mouth.

Late GI Toxicity From Radiation Treatment

Long-term effects on the intestines result from radiation damage to intestinal circulation and the associated inflammation in the colon or small intestine, called enteritis, which can result in ulcerations, fibrosis with narrowed areas or strictures, malabsorption of nutrients, and increased permeability called leaky gut. The ramifications of these issues should prompt professional consultation if digestive symptoms develop, persist, or worsen.

Prostate Radiation, Late Toxicities

Localized radiation treatment using newer technology has reduced acute symptoms.

Secondary GI effects are similar in both acute and persistent chronic situations, including diarrhea, urgency, intestinal spasms, and blood in the stool. Acutely, they resolve within a few months, while in the long term, there can be a small number of people in whom it remains persistent.
Genitourinary symptoms can occur chronically with current techniques, less than 10%, commonly being urethral stricture, bladder contracture, and cystitis.
Erectile dysfunction occurs in over one-third of men who were potent prior to radiation therapy, with more having erectile problems as time passes.

Late Gynecologic Issues From Radiation

Damage from localized radiation to the vagina and uterus damages the surface epithelial tissues and vascular supply.

It affects the bladder with chronic urgency and persistent frequency.
GI problems are chronic diarrhea, intestinal ulceration, abdominal pain, swelling, and blood in stool.
Vaginal narrowing is called stenosis due to radiation scarring, decreasing vaginal length, resulting in pain with intercourse.

Secondary Malignancy after Radiation Therapy

Combined multiple therapies in treatment increase the risk of secondary malignancy, decades later, by approximately 17-19% overall, but with RT alone, only 5% of cases.

The contributive risks for a second malignancy are related to the interplay of the type of tumor, the number and types of chemotherapies and their doses and length of use, while radiation factors involve the type of exposure, the particles, and the total dose needed.

But probably the greatest risks come from

Unchanged lifestyle choices that contributed to the initial cancer

and

Existing genetic predispositions

Post Radiation Soup

This is a nutritious way to warm and hydrate, soothe the throat and digestive tract, and increase body fluids.

One cup is used twice daily; this makes a few days' worth, and then refrigerate the remainder. Can vary the recipe depending on the amount desired

3 quarts of water
Shitake Mushrooms 8 pcs
Tofu ½-1 package firm, organic, rinsed well in water.
Onion 1 minced
Carrots 2 minced
Wakame seaweed 2oz, cut into 1-inch pieces.
Kombu seaweed 1oz, break into small pieces.
Organic Miso —To rebuild Yin or fluids and moisture in the body, use white miso. Red miso is considered yang or energy-enhancing, but red miso has gluten. It can be used much later in soup for increased energy. Start with 12 tbsp/ 3 quarts water.
Minced green scallions 4
Mung Beans
Simmer veggies when soup is ready, add Miso mixture at the end.

Wash and break up the seaweed, put it at the bottom of the pot, and cook it with the soup, then remove it.

Gently simmer the veggies for 30-45 minutes.

Then, put the miso into a bowl, add a small amount of soup broth, stir until mixed well, with no lumps, and add to the soup. Never boil the miso in the soup.

In classic Chinese medicine, the following are often added to the soup.

Coix (barley) 20gms, if no gluten problems.
Mung bean sprouts (help detox radiation)