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Overview of Radiation Therapy Ms. Mezie Laurence B. Ortiz, RRT June 2015
Goal of Radiation Therapy Aims of Radiation Therapy Members of the Radiation Therapy team
Forms of Radiation Therapy Dose of Radiation Target Margins Overview of Treatment Process Side effects of Radiation Therapy
Radiation Therapy • It is the use of high level radiation WHAT? (Megavoltage) to destroy cancer cells.
WHY?
HOW?
• Has its greatest effect on tissues that divide rapidly such as cancer cells. It destroys the cell ability to divide or multiply (LAW OF BERGONIE AND TRIBONDEAU) • With each treatment more of the cancer cells die and the tumor shrinks • Damage to healthy cells are the reason for SIDE EFFECTS of Radiotherapy
GOAL OF RADIOTHERAPY
CURATIVE also called RADICAL RADIOTHERAPY. In this treatment, radiation dose is given so high that some side effects are unavoidable, but theses are accepted as an inevitable part of attempted cure. Radiation can be used as treatment alone or be given in combination with CHEMOTHERAPY, SURGERY and other forms of treatment.
GOAL OF RADIOTHERAPY
CONSIDERED EMERGENCY CASES IN RADIOTHERAPY: • BONE METASTASIS •MASS OBSTRUCTING THE LUNGS •BRAIN METASTASIS
AIM OF RADIOTHERAPY The aim of radiotherapy is to deliver a PRECISE measured dose of radiation to a DEFINED tumor volume: With minimal damage to surrounding tissue. That results in eradication of tumor. That results in a high quality of life for the patient.
For prolongation of life at competitive cost. For effective palliation or prevention of symptoms of cancer including pain. For restoring luminal patency, skeletal integrity and organ function with minimal morbidity.
MEMBERS OF RADIOTHERAPY TEAM Radiation Oncologist Medical Physicist/ Dosimetrist Radiotherapy Technologist
RADIATION ONCOLOGIST
RADIATION ONCOLOGIST
XRAY IMAGE OF PELVIS
CT IMAGE PELVIS
MEDICAL PHYSICIST/DOSIMETRIST
RADIOTHERAPY TECHNOLOGIST
RADIOTHERAPY TECHNOLOGIST
RADIOTHERAPY TECHNOLOGIST IMMOBILIZATION DEVICES (ALPHA CRADLE)
RADIOTHERAPY TECHNOLOGIST IMMOBILIZATION DEVICE (THERMOPLASTIC MASK)
TWO FORMS OF RADIOTHERAPY
TWO FORMS OF RADIATION THERAPY EXTERNAL RADIATION THERAPY (TELETHERAPY) IN THIS TYPE OF TREATMENT, DOSES OF RADIATION ARE GIVEN TO A CAREFULLY DEFINED AREA THROUGH A MACHINE THAT DIRECTS THE HIGH-ENERGY RAYS OR PARTICLES FROM OUTSIDE THE BODY AT THE CANCER AND THE NORMAL TISSUES SURROUNDING IT.
INTERNAL RADIATION THERAPY (BRACHYTHERAPY) INTERNAL RADIATION THERAPY PLACES THE SOURCE OF THE HIGH-ENERGY RAYS INSIDE THE BODY, AS CLOSE AS POSSIBLE TO THE CANCER CELLS. THIS DELIVERS VERY INTENSE RADIATION TO A SMALL AREA OF THE BODY AND LIMITS THE DOSE TO NORMAL TISSUE. THE RADIOACTIVE SUBSTANCES USED TYPICALLY INCLUDE RADIUM, CESIUM, IODINE, AND PHOSPHORUS, AND THEY MAY BE IMPLANTED FOR ONLY A SHORT TIME OR LEFT IN PLACE PERMANENTLY. PATIENTS WITH RADIATION IMPLANTS SOMETIMES NEED TO BE ISOLATED FROM VISITORS SO AS NOT TO EXPOSE THEM TO RADIOACTIVITY
EXTERNAL BEAM RADIATION THERAPY (PHOTON BEAM)
LINEAR ACCELERATOR MACHINE ( DIRECT LINAC)
EXTERNAL BEAM RADIATION THERAPY (PHOTON BEAM)
LINEAR ACCELERATOR MACHINE ( HELICAL LINAC)
EXTERNAL BEAM RADIATION THERAPY (PROTON BEAM)
LINEAR ACCELERATOR MACHINE (LINAC)
Mechanism of ACTION
PHOTON VS. PROTON )
INTERNAL BEAM RADIATION THERAPY
INTERNAL BEAM RADIATION THERAPY
DOSE OF RADIATION
DOSE OF RADIATION determination
TOLERANCE DOSE •is the largest amount of dose that can be accepted without the production of injurious symptoms
Factors affecting TOLERANCE DOSE Dose per fraction/ dose rate
Volume irradiated Sensitivity of the tissues
Amount of recovery which can take place between fractions
Volume irradiated The smaller the volume to be treated the higher the total dose which may be tolerated. EXAMPLE:
Patient and Biological Factors The type of tissue treated, poor dietary or fluid intake or concomitant drug treatment, may affect the level of dose tolerated. Oxygen Effect Good oxygenation increases the chance of radiation damage to cells. Many of the cells within a large cell mass where there is no organized blood supply is hypoxic. Tumor cells are less oxygenated and therefore less sensitive to radiation. Cell Doubling Time One division of all cells in the mass. If the number of cells doubles within the time interval between two fractions, treatment may fail.
Fractionation Fractionation is the administration of a course of radiation treatment in a planned series of fractions of total dose. This allows recovery of normal cells while depleting the number of surviving tumor cells.
Fractionation
Dose per fraction/dose rate BODY PART
DOSE PRESCRIBED
DOSE PER DAY
TOTAL TREATMENT FRACTIONS/DAYS
BREAST
6040 cGy
180 cGy for 29 days then 200 cGy for 5 days
33 days
GYNE (CERVIX, UTERUS, OVARY
5040 cGy
180 cGy per day
28 days
WHOLE BRAIN
3000 cGy
300 cGy per day
10 days
BONE METS
3000 cGy
300 cGy per day
10 days
Dose per fraction/dose rate •The dose that can be tolerated by normal tissue in the treatment zone varies with the total time over which the dose is given. •Dose that could be given in a longer period of time is larger than could be given over a shorter period. •For a given volume, the size of each fraction dose and the time interval between fractions alters the biological effect. •The higher the fraction dose (or dose rate) the greater the late damage potential.
Dose per fraction/dose rate Missed treatments would lead to an overall treatment period which is significantly longer than intended.
Some patients (for head and neck) are at a survival disadvantage if treatment duration is lengthened. Because once some cells are killed the cell kinetics change and there is a potential for very rapid repopulation.
Fractionation Regimes Conventional fractionated courses consist of once-daily doses given 5 days per week, usually Monday to Friday. with recovery period at the weekend.
Less than 5 fractions per week Once-, twice-, or three times weekly treatments with higher dose of radiation. Potential for late radiation damage increases with high fraction doses.
Reason for lowered fractionation regimes Fewer visits and less traveling time for patients Shortage of treatment machine Clinical indications (for very sensitive tumor – skin lymphomas)
Fractionation Regimes Hyperfractionation Shortening the treatment course duration but giving a high number of small fractions. Given to tumors with a fast cell-doubling time such as 5 days. May result in more acute injury but an unchanged potential for late damage.
Target Margins ICRU Reports 50/62 recommendations for target delineation in which the target volume is separated into three distinct regions:
Target Margins ICRU Reports 50/62 recommendations for target delineation in which the target volume is separated into three distinct regions: Gross tumor volume (GTV) denotes the demonstrable tumor. Clinical Target volume (CTV) denotes the GTV and subclinical disease (region to account for uncertainties in microscopic tumor spread). Planning Target Volume (PTV) denotes the CTV and includes margins for geometric / position uncertainties. Usually 1.5 cm physical margin are set around the CTV.
Target Margins Treated volume is the volume of tissue enclosed by an isodose surface, selected and specified by the radiation oncologists as being appropriate to achieve the purpose of treatment. The treated volume is always larger than the PTV and usually has a simpler shape.
Irradiated volume is the volume of tissue that receives a dose considered significant in relation to tissue tolerance.
Overview of Treatment Process
EXTERNAL BEAM RADIATION THERAPY
Overview of Treatment Process 1. INITIAL CONSULTATION WITH RAD ONCO
Overview of Treatment Process 2. INFORMED CONSENT PROCESS (RAD ONCO)
Overview of Treatment Process 3. SIMULATION STAGE (RADIOTHERAPY TECHNOLOGIST)
3.1 DETERMINE PATIENT POSITION WITH APPROPRIATE IMMOBILIZATION DEVICE
3.1 ACQUIRE X-RAY OR CT SCAN IMAGE OF THE PART TO BE TREATED AS DETERMINED BY RAD ONCO.
Overview of Treatment Process 3. SIMULATION STAGE (RADIOTHERAPY TECHNOLOGIST)
3.3 Tatto Process It is necessary to make the marks permanent since this will be the basis for body alignment during the radiation therapy treatment
Overview of Treatment Process 3. SIMULATION STAGE (RADIOTHERAPY TECHNOLOGIST)
3.4 Documentation At the end of simulation stage a form called simulation worksheet or simulation form must be filled out by the Radiation Therapist since the data would be needed by the Medical Physicist for the Planning Stage.
Overview of Treatment Process 3. SIMULATION STAGE (RADIOTHERAPY TECHNOLOGIST)
Example Simulation Worksheet or Simulation Form
MEDICAL PHYSICIST/DOSIMETRIST Overview of Treatment Process 4. PLANNING STAGE (RAD ONCO & MED PHY)
(On this stage the Radiation Oncologist will draw / contour the treatment fields on the acquired images as well as dose prescription. After everything has been drawn the Medical Physicist would do a lot of calculations considering the tolerance dose of the part to be treated as well as its surrounding tissues).
Overview of Treatment Process After the simulation stage and planning stage, the Medical Physicist usually have 3-5 working days to complete everything for the patient to start the treatment
Overview of Treatment Process . BEAM VIEW
PLANNED IMAGE
BEAM VIEW
PORTAL IMAGE
Overview of Treatment Process Daily Treatments (Radiation Therapist) SCHEDULE: Monday-Friday FRACTION PER WEEK: usually ( 5 days a week) FRACTION PER DAY: usually Once a day or it can be given b.i.d if preferred by the RAD ONCO. CONSULTATION: once a week the patient is seen by the Radiation Oncologist in order to monitor patient’s condition and answer the patient’s question regarding the treatment.
Overview of Treatment Process End Of Treatment Visit Once radiation treatment had been completed, patient will have final visit with his attending Physician. The doctor will make an evaluation examination and followup care.
Side Effects The high doses of radiation that damage or destroy cancer cells also can hurt normal cells, causing side effects. These will vary depending on the area treated and the dose received. Factors to Consider Total dose delivered Time over which the dose was delivered Volume irradiated
Side Effects The risk of side effects is usually less than the benefits of killing cancer cells. It is usually temporary and will disappear gradually when therapy is complete. Side effects are generally limited to the region of the body being treated.
Side Effects on SKIN Radiation Dermatitis is a skin condition that is a common side effect of radiation therapy. The affected skin becomes painful, red, itchy, and blistered.
Side Effects Nutritional problems Radiation can affect the membranes of the mouth and/or gastrointestinal tract, causing discomfort while swallowing, nausea, altered taste of foods, and diarrhea.
Side Effects Fatigue or weakness is one of the most common side effects of radiation therapy. Patients are not restricted from their normal activity like going to work. However, they should balance normal activity with period of rest.
THANK YOU
Goal of Radiation Therapy Aims of Radiation Therapy Members of the Radiation Therapy team
Forms of Radiation Therapy Dose of Radiation Target Margins Overview of Treatment Process Side effects of Radiation Therapy
Radiation Therapy • It is the use of high level radiation WHAT? (Megavoltage) to destroy cancer cells.
WHY?
HOW?
• Has its greatest effect on tissues that divide rapidly such as cancer cells. It destroys the cell ability to divide or multiply (LAW OF BERGONIE AND TRIBONDEAU) • With each treatment more of the cancer cells die and the tumor shrinks • Damage to healthy cells are the reason for SIDE EFFECTS of Radiotherapy
GOAL OF RADIOTHERAPY
CURATIVE also called RADICAL RADIOTHERAPY. In this treatment, radiation dose is given so high that some side effects are unavoidable, but theses are accepted as an inevitable part of attempted cure. Radiation can be used as treatment alone or be given in combination with CHEMOTHERAPY, SURGERY and other forms of treatment.
GOAL OF RADIOTHERAPY
CONSIDERED EMERGENCY CASES IN RADIOTHERAPY: • BONE METASTASIS •MASS OBSTRUCTING THE LUNGS •BRAIN METASTASIS
AIM OF RADIOTHERAPY The aim of radiotherapy is to deliver a PRECISE measured dose of radiation to a DEFINED tumor volume: With minimal damage to surrounding tissue. That results in eradication of tumor. That results in a high quality of life for the patient.
For prolongation of life at competitive cost. For effective palliation or prevention of symptoms of cancer including pain. For restoring luminal patency, skeletal integrity and organ function with minimal morbidity.
MEMBERS OF RADIOTHERAPY TEAM Radiation Oncologist Medical Physicist/ Dosimetrist Radiotherapy Technologist
RADIATION ONCOLOGIST
RADIATION ONCOLOGIST
XRAY IMAGE OF PELVIS
CT IMAGE PELVIS
MEDICAL PHYSICIST/DOSIMETRIST
RADIOTHERAPY TECHNOLOGIST
RADIOTHERAPY TECHNOLOGIST
RADIOTHERAPY TECHNOLOGIST IMMOBILIZATION DEVICES (ALPHA CRADLE)
RADIOTHERAPY TECHNOLOGIST IMMOBILIZATION DEVICE (THERMOPLASTIC MASK)
TWO FORMS OF RADIOTHERAPY
TWO FORMS OF RADIATION THERAPY EXTERNAL RADIATION THERAPY (TELETHERAPY) IN THIS TYPE OF TREATMENT, DOSES OF RADIATION ARE GIVEN TO A CAREFULLY DEFINED AREA THROUGH A MACHINE THAT DIRECTS THE HIGH-ENERGY RAYS OR PARTICLES FROM OUTSIDE THE BODY AT THE CANCER AND THE NORMAL TISSUES SURROUNDING IT.
INTERNAL RADIATION THERAPY (BRACHYTHERAPY) INTERNAL RADIATION THERAPY PLACES THE SOURCE OF THE HIGH-ENERGY RAYS INSIDE THE BODY, AS CLOSE AS POSSIBLE TO THE CANCER CELLS. THIS DELIVERS VERY INTENSE RADIATION TO A SMALL AREA OF THE BODY AND LIMITS THE DOSE TO NORMAL TISSUE. THE RADIOACTIVE SUBSTANCES USED TYPICALLY INCLUDE RADIUM, CESIUM, IODINE, AND PHOSPHORUS, AND THEY MAY BE IMPLANTED FOR ONLY A SHORT TIME OR LEFT IN PLACE PERMANENTLY. PATIENTS WITH RADIATION IMPLANTS SOMETIMES NEED TO BE ISOLATED FROM VISITORS SO AS NOT TO EXPOSE THEM TO RADIOACTIVITY
EXTERNAL BEAM RADIATION THERAPY (PHOTON BEAM)
LINEAR ACCELERATOR MACHINE ( DIRECT LINAC)
EXTERNAL BEAM RADIATION THERAPY (PHOTON BEAM)
LINEAR ACCELERATOR MACHINE ( HELICAL LINAC)
EXTERNAL BEAM RADIATION THERAPY (PROTON BEAM)
LINEAR ACCELERATOR MACHINE (LINAC)
Mechanism of ACTION
PHOTON VS. PROTON )
INTERNAL BEAM RADIATION THERAPY
INTERNAL BEAM RADIATION THERAPY
DOSE OF RADIATION
DOSE OF RADIATION determination
TOLERANCE DOSE •is the largest amount of dose that can be accepted without the production of injurious symptoms
Factors affecting TOLERANCE DOSE Dose per fraction/ dose rate
Volume irradiated Sensitivity of the tissues
Amount of recovery which can take place between fractions
Volume irradiated The smaller the volume to be treated the higher the total dose which may be tolerated. EXAMPLE:
Patient and Biological Factors The type of tissue treated, poor dietary or fluid intake or concomitant drug treatment, may affect the level of dose tolerated. Oxygen Effect Good oxygenation increases the chance of radiation damage to cells. Many of the cells within a large cell mass where there is no organized blood supply is hypoxic. Tumor cells are less oxygenated and therefore less sensitive to radiation. Cell Doubling Time One division of all cells in the mass. If the number of cells doubles within the time interval between two fractions, treatment may fail.
Fractionation Fractionation is the administration of a course of radiation treatment in a planned series of fractions of total dose. This allows recovery of normal cells while depleting the number of surviving tumor cells.
Fractionation
Dose per fraction/dose rate BODY PART
DOSE PRESCRIBED
DOSE PER DAY
TOTAL TREATMENT FRACTIONS/DAYS
BREAST
6040 cGy
180 cGy for 29 days then 200 cGy for 5 days
33 days
GYNE (CERVIX, UTERUS, OVARY
5040 cGy
180 cGy per day
28 days
WHOLE BRAIN
3000 cGy
300 cGy per day
10 days
BONE METS
3000 cGy
300 cGy per day
10 days
Dose per fraction/dose rate •The dose that can be tolerated by normal tissue in the treatment zone varies with the total time over which the dose is given. •Dose that could be given in a longer period of time is larger than could be given over a shorter period. •For a given volume, the size of each fraction dose and the time interval between fractions alters the biological effect. •The higher the fraction dose (or dose rate) the greater the late damage potential.
Dose per fraction/dose rate Missed treatments would lead to an overall treatment period which is significantly longer than intended.
Some patients (for head and neck) are at a survival disadvantage if treatment duration is lengthened. Because once some cells are killed the cell kinetics change and there is a potential for very rapid repopulation.
Fractionation Regimes Conventional fractionated courses consist of once-daily doses given 5 days per week, usually Monday to Friday. with recovery period at the weekend.
Less than 5 fractions per week Once-, twice-, or three times weekly treatments with higher dose of radiation. Potential for late radiation damage increases with high fraction doses.
Reason for lowered fractionation regimes Fewer visits and less traveling time for patients Shortage of treatment machine Clinical indications (for very sensitive tumor – skin lymphomas)
Fractionation Regimes Hyperfractionation Shortening the treatment course duration but giving a high number of small fractions. Given to tumors with a fast cell-doubling time such as 5 days. May result in more acute injury but an unchanged potential for late damage.
Target Margins ICRU Reports 50/62 recommendations for target delineation in which the target volume is separated into three distinct regions:
Target Margins ICRU Reports 50/62 recommendations for target delineation in which the target volume is separated into three distinct regions: Gross tumor volume (GTV) denotes the demonstrable tumor. Clinical Target volume (CTV) denotes the GTV and subclinical disease (region to account for uncertainties in microscopic tumor spread). Planning Target Volume (PTV) denotes the CTV and includes margins for geometric / position uncertainties. Usually 1.5 cm physical margin are set around the CTV.
Target Margins Treated volume is the volume of tissue enclosed by an isodose surface, selected and specified by the radiation oncologists as being appropriate to achieve the purpose of treatment. The treated volume is always larger than the PTV and usually has a simpler shape.
Irradiated volume is the volume of tissue that receives a dose considered significant in relation to tissue tolerance.
Overview of Treatment Process
EXTERNAL BEAM RADIATION THERAPY
Overview of Treatment Process 1. INITIAL CONSULTATION WITH RAD ONCO
Overview of Treatment Process 2. INFORMED CONSENT PROCESS (RAD ONCO)
Overview of Treatment Process 3. SIMULATION STAGE (RADIOTHERAPY TECHNOLOGIST)
3.1 DETERMINE PATIENT POSITION WITH APPROPRIATE IMMOBILIZATION DEVICE
3.1 ACQUIRE X-RAY OR CT SCAN IMAGE OF THE PART TO BE TREATED AS DETERMINED BY RAD ONCO.
Overview of Treatment Process 3. SIMULATION STAGE (RADIOTHERAPY TECHNOLOGIST)
3.3 Tatto Process It is necessary to make the marks permanent since this will be the basis for body alignment during the radiation therapy treatment
Overview of Treatment Process 3. SIMULATION STAGE (RADIOTHERAPY TECHNOLOGIST)
3.4 Documentation At the end of simulation stage a form called simulation worksheet or simulation form must be filled out by the Radiation Therapist since the data would be needed by the Medical Physicist for the Planning Stage.
Overview of Treatment Process 3. SIMULATION STAGE (RADIOTHERAPY TECHNOLOGIST)
Example Simulation Worksheet or Simulation Form
MEDICAL PHYSICIST/DOSIMETRIST Overview of Treatment Process 4. PLANNING STAGE (RAD ONCO & MED PHY)
(On this stage the Radiation Oncologist will draw / contour the treatment fields on the acquired images as well as dose prescription. After everything has been drawn the Medical Physicist would do a lot of calculations considering the tolerance dose of the part to be treated as well as its surrounding tissues).
Overview of Treatment Process After the simulation stage and planning stage, the Medical Physicist usually have 3-5 working days to complete everything for the patient to start the treatment
Overview of Treatment Process . BEAM VIEW
PLANNED IMAGE
BEAM VIEW
PORTAL IMAGE
Overview of Treatment Process Daily Treatments (Radiation Therapist) SCHEDULE: Monday-Friday FRACTION PER WEEK: usually ( 5 days a week) FRACTION PER DAY: usually Once a day or it can be given b.i.d if preferred by the RAD ONCO. CONSULTATION: once a week the patient is seen by the Radiation Oncologist in order to monitor patient’s condition and answer the patient’s question regarding the treatment.
Overview of Treatment Process End Of Treatment Visit Once radiation treatment had been completed, patient will have final visit with his attending Physician. The doctor will make an evaluation examination and followup care.
Side Effects The high doses of radiation that damage or destroy cancer cells also can hurt normal cells, causing side effects. These will vary depending on the area treated and the dose received. Factors to Consider Total dose delivered Time over which the dose was delivered Volume irradiated
Side Effects The risk of side effects is usually less than the benefits of killing cancer cells. It is usually temporary and will disappear gradually when therapy is complete. Side effects are generally limited to the region of the body being treated.
Side Effects on SKIN Radiation Dermatitis is a skin condition that is a common side effect of radiation therapy. The affected skin becomes painful, red, itchy, and blistered.
Side Effects Nutritional problems Radiation can affect the membranes of the mouth and/or gastrointestinal tract, causing discomfort while swallowing, nausea, altered taste of foods, and diarrhea.
Side Effects Fatigue or weakness is one of the most common side effects of radiation therapy. Patients are not restricted from their normal activity like going to work. However, they should balance normal activity with period of rest.
THANK YOU
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