Overview of Radiation Therapy

Question 1

What is radiation therapy?

Answer 1

Radiation therapy uses ionizing radiation (x-rays, gamma rays) to treat cancer i.e. to destroy cancerous cells.

Question 2

What are the two techniques in radiation therapy that are used to treat cancer?

Answer 2

External beam

Brachytherapy

Question 3

When was radiation discovered?

Answer 3

In 1895, Wilhelm Roentgen discovered that an energy ray was produced by passing an electrical current through a cathode ray tube.

Question 4

What did Marie Curie and her husband Pierre discover in 1898?

Answer 4

Marie Curie and her husband Pierre isolated the first known radioactive elements and named them Radium and Polonium.

Question 5

What kind of treatment was the first radiation treatment?

Answer 5

First radiation treatments meant that the radioactive source had to be in close proximity or within the cancer (brachytherapy)

Question 6

How was radiation measured at fist?

Answer 6

At first, the radiation dose was measured by the degree of skin erythema. Very little safety!

Question 7

What is the current unit of measurement for radiation?

Answer 7

The term Gray (Gy) replaced the rad as the international standard measure of radiation dose.

Question 8

How many patients with cancer receive radiation therapy?

Answer 8

More than 60% of patients with cancer will receive radiation therapy at some time during their illness.

Question 9

What are the uses of radiation treatment?

Answer 9

Radiation therapy can be used in the palliation of symptoms to enhance quality of life eg. to relieve/control pain, bleeding, obstruction

Question 10

What is the goal of radiation therapy?

Answer 10

The aim of radiation therapy is to cause damage to the cancerous cells whilst minimizing the risk to surrounding healthy tissue. (localized therapy).

Question 11

How does radiation therapy work?

Answer 11

The damage inflicted by radiation therapy causes the cancerous cells to sop reproducing and thus the tumour shrinks.

Question 12

What is radiosensitivity? Which cells are highest in radiosensitivity?

Answer 12

Cells can vary in sensitivity to radiation

Generally, rapidly dividing cells (cancerous and normal) are most sensitive

Question 13

Which cancers are highly radiosensitive?

Answer 13

Lymphoma, leukemia, seminoma, and dysgerminoma are highly radiosensitive.
Squamous cell cancer of the oropharyngeal, glottis, bladder, skin, cervical epithelia, adenocarcinomas of the alimentary tract are fairly high in radiosensitivity

Question 14

Which cancers are low in radiosensitivity?

Answer 14

Breast, salivary gland tumors, hepatomas, renal cancer, pancreatic cancer, chondrosarcoma, osteogenic sarcoma are all fairly low in radiosensitivity
Rhabdomyosarcoma, leimyosarcoma, ganglioneurofibrosarcoma have a low level of radiosensitivity

Question 15

What is brachytherapy?

Answer 15

This involves placing radioactive implants in the form of seeds, wires or pellets directly into the tumour.Such implants may be temporary or permanent depending on the implant and the tumour itself.The benefit of such a method is that the tumour receives nearly all of the dose whilst healthy tissue hardly receives any.

Question 16

What is irradiation using high energy X-rays?

Answer 16

Or, from high energy x-rays..The x-rays are generated by a linear accelerator (linac).The linac fires high energy electrons at a metal target and when the electrons strike the target, x-rays are produced.The x-rays produced are shaped into a narrow beam by movable metal shutters

Question 17

What are some general side effects of radiation therapy?

Answer 17

Fatigue
Bone marrow suppression
Skin
 - moist desquamation
 - dry desquamation

Question 18

What are some site-specific radiation effects for pelvic cancers?

Answer 18

Pelvis 
Diarrhea
Cystitis
Erectile dysfunction
Vaginal stenosis
Sterility
Nausea and vomiting
Premature menopause
Vagina  - inflammation, dryness, dyspareunia

Question 19

What are some site-specific radiation side effects for skin cancers?

Answer 19

Erythema
Pigmentation
Desquamation - dry and moist
Alopecia

Question 20

What are some mone marrow side effects of radiation?

Answer 20

Myelosuppression

Question 21

What are some site-specific sife effects of radiation for brain cancer?

Answer 21

Alopecia

Somnolence

Question 22

What are some site-specific radiation side effects for head and neck cancer?

Answer 22

Mucositis
Xerostomia
Changes in taste
Laryngitis

Question 23

What are some site specific side effects of radiation for chest cancer?

Answer 23

Radiation pneumonitis
Esophagitis
Dysphagia

Question 24

What are some site specific side effects of radiation for abdominal cancers?

Answer 24

Diarrhea
Fat malabsorption
Nausea and vomiting
Gastritis

Question 25

What is a vero machine? What does it do?

Answer 25

the Vero machinery is an all-in-one radiation/imaging/patient positioning system that focuses the radiation dose on the central target (tumour) while sparing surrounding healthy tissues and organs.
It is capable of tracking moving tumours, referring to the fact that tumours move when patients breath or the heart pumps so focusing a beam of radiation only on a tumour is tricky
With the dynamic, six-dimensional patient positioning and tumour tracking capabilities of the Vero system, there is less risk of healthy tissue receiving radiation. To do that, Vero acquires breathing signals of patients and then correlates that with the position of the tumour using infrared signals.
The $6.5-million fundraising goal for stereotactic body radiation therapy (SBRT) machinery called Vero is the most ambitious campaign launched for technological equipment purchased with private donations to the BC Cancer Foundation