Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.
In radiation therapy (also called radiotherapy), high-energy rays
are used to damage cancer cells and stop them from growing and
dividing. A specialist in radiation therapy is called a radiation
oncologist.
Like surgery, radiation therapy is a local treatment; it affects
cancer cells only in the treated area. Radiation can come from a
machine (external radiation). It can also come from an implant (a
small container of radioactive material) placed directly into or near
the tumor (internal radiation). Some patients receive both kinds of
radiation therapy.
External radiation therapy is usually given on an outpatient basis in
a hospital or clinic 5 days a week for a number of weeks. Patients are
not radioactive during or after the treatment.
For internal radiation therapy, the patient stays in the hospital for
a few days. The implant may be temporary or permanent. Because the
level of radiation is highest during the hospital stay, patients may
not be able to have visitors or may have visitors only for a short
time. Once an implant is removed, there is no radioactivity in the
body. The amount of radiation in a permanent implant goes down to a
safe level before the patient leaves the hospital.
With radiation therapy, the side effects depend on the treatment dose and the part of
the body that is treated. The most common side effects are tiredness, skin
reactions (such as a rash or redness, permanent pigmentation, and scarring) in
the treated area, and loss of appetite. Radiation therapy can cause
inflammation of tissues and organs in and around the body site
radiated. This can cause symptoms that depend on what organs are
affected and to what degree. For example, radiation can inflame skin to cause a burn or permanent pigmentation. It can also irritate the colon and cause diarrhea. Radiation therapy can also
cause a decrease in the number of white blood cells, cells that help
protect the body against infection.
Although the side effects of radiation therapy can be unpleasant, they can usually be treated or
controlled. It also helps to know that, in most cases, they are not
permanent. To a great degree, the possible side effects of radiation therapy depend on the location and the amount of radiation.
Lung cancer kills more men and women than any other form of cancer. Eight out of 10 lung cancers are due
to tobacco smoke. Lung cancers are classified as either small cell or non-small
cell cancers.
A brain tumor can be either benign (non cancerous) or malignant (cancerous), primary, or secondary. Causes and risk factors include age, gender, family history, and exposure to chemicals. Symptoms range from headaches, leg and feet numbness to seizures. Treatment is dependant upon the type and location of the brain tumor.
Pancreatic cancer is a malignant tumor of the pancreas. Pancreatic cancer has been called a "silent" disease because early pancreatic cancer usually does not cause symptoms.
There are many types of ovarian cancer, epithelial carcinoma is the most common. Women with a family history of ovarian cancer have an increased risk of developing the disease. Some ovarian cancer symptoms include abdominal pain, nausea, diarrhea, constipation, and abnormal vaginal bleeding, however, they usually do not present until the disease has progressed. Early diagnosis is important for successful treatment.
In the U.S., more than 2,000 people are diagnosed with bone cancer every year. There are many types of bone cancer. The most common forms of bone cancer are osteosarcoma, Ewing's sarcoma, chondrosarcoma, malignant fibrous histiocytoma, fibrosarcoma, and chordoma. Pain is the most common symptom. Treatment usually involves surgery, chemotherapy, and radiation therapy.
Colon cancer is a malignancy that arises from the inner lining of the colon. Most, if not all, of these cancers develop from colonic polyps. Removal of these precancerous polyps can prevent colon cancer.
Low testosterone can affect both men and women. Causes of low testosterone in males include undescended testicles and injury to the scrotum. Low testosterone in females includes ovary conditions. Treatment for low testosterone in men includes testosterone replacement therapy. Currently there is no FDA approved testosterone treatment for women.
Skin cancer is the most common form of cancer
in humans. There are three main types of skin cancer; basal cell carcinoma and
squamous cell carcinoma (the nonmelanoma skin cancers), and melanoma.
Though the cause of stomach cancer is unknown, risk factors for stomach cancer include diet, H. pylori infection, smoking age, gastritis, stomach surgery, family history, and pernicious anemia. Symptoms include stomach discomfort, feeling full after a small meal, nausea and vomiting, and weight loss. Treatment depends upon staging and may involve surgery, radiation therapy, or chemotherapy.
Though uterine cancer's cause is unknown, there are many factors that will put a woman at risk, including: over age 50, endometrial hyperplasia, using hormone replacement therapy, obesity, using tamoxifen, being Caucasian, having colorectal cancer. Symptoms of cancer of the uterus (endometrial cancer) include abnormal vaginal bleeding, painful urination, painful intercourse, and pelvic pain. Treatment depends on staging and may include radiation therapy or hormone therapy.
There are four major types of thyroid cancer: papillary, follicular, medullary, and anaplastic thyroid cancer. Tumors on the thyroid are referred to as thyroid nodules. Symptoms of thyroid cancer include swollen lymph nodes, pain in the throat, difficulty swallowing, hoarseness, and a lump near the Adam's apple. Treatment usually involves chemotherapy, surgery, radioactive iodine, hormone treatment or external radiation and depends upon the type of thyroid cancer, the patient's age, the tumor size, and whether the cancer has metastasized.
Non-Hodgkin's lymphoma is cancer of the lymphatic system, a vital part of the body's immune system. Symptoms include swollen lymph nodes, fever, night sweats, coughing, weakness, chest pain, unexplained weight loss, and abdominal pain. Treatment depends on which type of non-Hodgkin's lymphoma you have, the stage of the cancer, your age, how fast the cancer is growing, and whether you have other health problems.
Cervical cancer is cancer of the entrance to the womb (uterus). Regular pelvic exams and Pap testing can detect precancerous changes in the cervix. Precancerous changes in the cervix may be treated with cryosurgery, cauterization, or laser surgery. The most common symptom of cancer of the cervix is abnormal bleeding.
Breast cancer is the most common cancer in women and the second most common cause of cancer death in women in the U.S. Symptoms include a lump in the breast or underarm area, nipple pain, change in breast size or shape, an inverted nipple, nipple discharge, and breast skin changes. Treatment may involve chemotherapy, radiation therapy, biological therapy, hormone therapy, or surgery.
There are several types of kidney cancer, including renal cell cancer (renal adenocarcinoma or hypernephroma), transitional cell carcinoma, and Wilms tumor. Symptoms of kidney cancer include blood in the urine, an abdominal lump or mass, chronic pain in the side, and tiredness. Treatment of kidney cancer--which may include surgery, arterial embolization, radiation therapy, biological therapy or chemotherapy--depends upon the stage of the disease and the patient's overall health.
Treatment for bladder cancer depends on the stage of the disease, the grade of the tumor, and the type of bladder cancer. Options for treatment include surgery, radiation therapy, chemotherapy, and biological therapy.
The term oral cancer includes cancer of the mouth (oral cavity) and the back of the mouth (oropharynx). Red and white patches inside the mouth, bleeding, loose teeth, pain upon swallowing, a lump in the neck, earache, and a sore on your lip or in your mouth that won't heal are all symptoms of oral cancer. Treatment for oral cancer depends upon the staging of the disease and usually involves surgery, radiation therapy, or chemotherapy.
Esophageal cancer is a disease in which malignant cells form in the esophagus. Risk factors of cancer of the esophagus include smoking, heavy alcohol use, Barrett's esophagus, being male and being over age 60. Severe weight loss, vomiting, hoarseness, coughing up blood, painful swallowing, and pain in the throat or back are symptoms. Treatment depends upon the size, location and staging of the cancer and the health of the patient.
Melanoma is a type of skin cancer which begins in skin cells called melanocytes and affects more than 53,600 people in the United States each year. These melanocytes can grow together to form benign moles which, after a change in size, shape, or color can be a sign of melanoma. Caused by sun exposure, early detection becomes extremely important to avoid a spread to other areas of the body. Diagnosis is confirmed through a biopsy of the abnormal skin and treatment depends on the extent and characteristics of the patient.
Multiple myeloma is a form of cancer that develops in plasma cells, the white blood cells that make antibodies. Symptoms include bone pain, weakness, extreme thirst, nausea, frequent urination, and broken bones. Treatment of multiple myeloma depends upon the staging and symptoms of the disease.
Hodgkin's disease is a cancer of the lymphatic system with symptoms that include unexplained, recurring fevers, unexplained weight loss, itchy skin, and painless swelling of the lymph nodes in the neck, underarm, and groin. Treatment for adult Hodgkin's disease depends on the staging of the disease, the lymph nodes' size, and the health of the patient.
Prostate cancer is an uncontrolled (malignant) growth of cells in the prostate gland. Prostate cancer is the second
leading cause of death of males in the U.S. Prostate cancer is often initially
suspected because of an abnormal PSA blood test or a hard nodule (lump) felt on
the prostate gland during a routine rectal examination.
A keloid is a scar that doesn't know when to stop. When the cells keep on reproducing, the result is an overgrown (hypertrophic) scar or a keloid. A keloid looks shiny and is often dome-shaped, ranging in color from slightly pink to red. It feels hard and thick and is always raised above the surrounding skin.
The spleen enlarges if it is asked to do excessive work in filtering or manufacturing blood cells, if there is abnormal blood flow to it, or if it is invaded with abnormal cells or deposits. Symptoms of an enlarged spleen may include weakness and fatigue, easy bleeding, and poor white blood cell function. Treatment of an enlarged spleen is focused toward the cause of the splenomegaly. Surgery may be required to remove the spleen.
Cancer is a disease caused by an abnormal growth of cells, also called malignancy. It is a group of 100 different diseases, and is not contagious. Cancer can be treated through chemotherapy, a treatment of drugs that destroy cancer cells.
Neutropenia is a marked decrease in the number of neutrophils, neutrophils being a type of white blood cell (specifically a form of granulocyte) filled with neutrally-staning granules, tiny sacs of enzymes that help the cell to kill and digest microorganisms it has engulfed by phagocytosis.
Thrombocytopenia refers to a decreased number of platelets in the blood. There are many causes of thrombocytopenia such as decreased platelet production (viral infections for example rubella, mumps, chickenpox, hepatitis C, and HIV); increased platelet destruction or consumption (for example sulfonamide antibiotics, heparin, blood transfusions, and lupus); or increased splenic sequestration (enlarged spleen due to conditions for example liver disease, blood cancers, and more). Treatment of thrombocytopenia depends on the cause.
Cushing's syndrome, sometimes referred to as hypercortisolism, is a hormonal disorder caused by prolonged exposure to high levels of the hormone cortisol. Symptoms may include obesity, thinning arms and legs, a rounded face, and increased fat around the neck. Some causes of Cushing's syndrome is from taking glucocorticoid hormones such as prednisone for inflammatory diseases. Treatment for Cushing's syndrome depends on the cause.
Symptoms of cancer of the larynx, the organ at the front of the neck, include hoarseness, a lump in the neck, sore throat, cough, problems breathing, bad breath, earache, and weight loss. Treatment for larynx cancer depends on the stage (the extent) of the disease. Radiation therapy, surgery, and chemotherapy are all forms of treatment for laryngeal cancer.
Paget's disease of the nipple, also called Paget's
disease of the breast, is an uncommon type of cancer that forms in or around the
nipple (1, 2, 3). More than 95 percent of people with Paget's disease of the
nipple also have underlying breast cancer; however, Paget's disease of the
nipple accounts for less than 5 percent of all breast cancers
(1). For instance, of the 211,240 new
cases of breast cancer projected to be diagnosed in 2005, fewer than 11,000 will
also involve Paget's disease of the nipple (4).
Most patients diagnosed with Paget's disease of the
nipple are over age 50, but rare cases have been diagnosed in patients in their
20s (1). The average age at diagnosis is 62 for women and 69 for men. The disease is rare among both
women and men.