Radiation Oncology Speciality by Dr.Majed Alghamdi

Radiation Oncology
Majed Alghamdi, MBBS (H), FRCPC, DABR
Consultant Radiation Oncologist
Radiation Therapy Health Professions Conference 2020 Jeddah Jan 30, 2020

Objectives
Majed Alghamdi, MD,FRCPC, DABR Health Professions Conference 2020
To know what is radiation therapy/radiation treatment and Radiation Oncology?
To know the general principles of delivering radiation treatment.
To know different types of radiation therapy
To know the common indications for radiation treatment.
To know the common side effects of treating common tumor sites.

Introduction- Development of
Radiotherapy
-Discovery of X-rays 1895 by Wilhelm
Röntgen >> used for diagnostic radiology
-Discovery of radioactivity 1896 by Henri
becquerel and Marie Curie >> used for skin
cancers treatment
All of them won Nobel prize…

Question!
 If you have cancer, which treatment would you prefer:
 Surgery
 Radiotherapy
 Chemotherapy
 Immunotherapy
 Hormonal therapy
 All of the above
>> In reality, most patients will get more than one treatment depending on patient and disease
factors and taking into consideration the trade off between efficacy and toxicity..

Important !
 Cancer treatment is multidisciplinary and it involves all relevant specialties (surgery + medical
oncology + radiation oncology + radiology + pathology etc)
 The advances in cancer therapy is multidirectional in all aspects of therapies ( surgery,
systemic therapy and radiotherapy)
 Contemporary cancer treatment involves integration of multiple treatment modalities and It
is unlikely that one treatment modality is vanishing or eliminating other modalities in the
foreseeable future.
 Surgeon (oncology surgeon/neurosurgeon/head and neck etc) >> removes cancer/tumor
 Medical Oncologist >> prescribes systemic therapy (chemotherapy, hormonal, targeted
therapy and immunotherapy etc)
 Radiation Oncologist >> prescribes radiotherapy (see next slides)

Training- physicians
Program After medical school Local program
Medical Oncology >Internal medicine (3-4 years), then
>2-year oncology, then
>1-2 years subspecialty
Available
Radiation Oncology >5-year program, then
Recently became available

Radiation therapy staff
Staff Training Role
Radiation Oncologist Medical school, then
>5-year program, then
Diagnose, determine type and
dose and prescribe the
radiotherapy treatment
Medical physicist Medical physics (4 yrs)
MSc
Residency (2yrs)
+/-PhD
Machine maintenance
Create and check plans
Dosimetrists (planner) Physicists
Therapist + training
Or separate program
Design radiation plans
Radiation therapist 4-5 years in north America and KSA
3 years in UK
Position the patient and deliver
radiation therapy

Radiation Oncology as a career: summary
Advantages:
Competent clinical skills
Excellent communication skills
Combines noninvasive and invasive innovative techniques
Excellent lifestyle
Opportunities for clinical oncology, basic and technology-based research
Disadvantages:
Requires tertiary cancer center equipped with advanced machines for practice.

Definitions
Radiation therapy: the process of preparing a patient and
treating him/her with ionizing radiation.
Radiation Treatment (radiotherapy): The actual delivery of
ionizing radiation.
Radiation Oncology: a branch of medicine in which a qualified
and certified physician uses ionizing irradiation to treat
malignant or benign tumors or conditions.

Radiation spectrum
 Electromagnetic spectrum. Only Gamma and X-rays are ionizing!

Radiation units
Rontgen: measures radiation dose in the air
Grey: absorbed radiation energy by unit mass of tissue (clinical
radiation dose)
Bq: unit for radioactivity: 1 Bq= 1 disintegration/sec

External beam radiotherapy (EBRT)
a) 2D/3D/IMRT/VMAT
b) Intra-operative radiotherapy
c) Stereotactic Radiosurgery
Brachytherapy
Radiation types (details in next slides)

EBRT
Types of EBRT treatments:
Photons (x-rays and gamma rays)
Electrons
Particles (eg. Protons)
EBRT: using external device to deliver radiation to the tumor
through the patients’ skin
Examples of EBRT using photons: breast cancer, rectum, lung,
prostate and skin cancers
Examples of EBRT using electrons: skin cancers
Examples of EBRT using protons: CNS and pediatric cancers

EBRT machines

EBRT: 2D radiotherapy
 Historical treatment <1990
 Using AP and lateral X-rays
to define treatment fields
(based on bony anatomy
only)
 Lots of toxicity
 No longer used

EBRT: 3D Conformal Radiation Therapy
>1990
Using CT scan to define
treatment fields
Using multiple beams to
increase tumor coverage
and reduce dose to
adjacent tissues
Still cannot ”shape”
radiation dose around
tumor

EBRT: Intensity Modulated Radiotherapy
“IMRT”
>2005
It’s 3D planning with
different dose intensity
within the same fields
Better ability to shape
dose around targets than
3D treatment
Longer radiation
planning and delivery
time
3D conformal radiotherapy IMRT
High dose region
in Red

EBRT: External Beam plan: Multiple fields
(beams)
To understand difference
between IMRT and 3D
radiotherapy, we should
look at the beam (field)
from inside

EBRT: IMRT, dividing beam (field) into small
beamlets with different dose intensities
3D radiotherapy: open beam
IMRT: Beamlet # 1
IMRT: Beamlet # 2

EBRT: Intensity Modulated Radiotherapy“IMRT”:
Parotid sparing (example)
IMRT 3D conformal

Volumetric Modulated Arc Therapy
“VMAT”
>2010
3D planning
Using moving ”rapid arc”
delivery method
Improved ability to avoid
parotid in some cases
Faster treatment time than
IMRT
VMAT IMRT

Stereotactic Body Radiation Therapy
“SBRT”
>2014
3D planning
Using ”rapid arc” or static fields
High dose per fraction (ablative)
Limited No. of fractions (</=5)
Useful for re-irradiation of recurrent
tumor when salvage surgery is not
possible

Proton Therapy
One new center in KSA- Riyadh
It has no “exist” dose to critical
structures beyond target
Excellent in sparing adjacent
brainstem, spinal cord and optic
pathway for skull base tumors
Helpful in re-irradiation especially in
avoiding carotid artery
Helpful for pediatric cases where
lowering overall radiation dose to
other tissues is needed
Proton Non-Proton

Radiation types
Brachytherapy: using radioactive sources that are internally delivered
into or adjacent to the tumor
Classifications of Brachytherapy:
• High rate vs. low rate
• Intra-cavitary vs. intra-stitial vs. intravascular
Example1: Iridium 92 for cervix or endometrial cancers using vaginal
applicator
Example2: Iodine 125 for prostate cancers using radioactive seeds that
are permanently implanted directly into the prostate through
perineum
a) 2D/3D/IMRT/VMAT
Brachytherapy

Brachytherapy: prostate, cervix and
endometrial cancers
Prostate brachytherapy Gyne Brachytherapy

Disclosures
Intraoperative radiotherapy: for colon and rectum cancers
Used at time of surgery when the patient is on the OR table
a) 2D/3D/IMRT/VMAT
Brachytherapy

Intraoperative Radiotherapy

Radiation types
Stereotactic Radiosurgery: for brain, spine, lung, liver, prostate,
adrenals, and lymph noes
Stereotaxy: precise 3D localization of tumor
Radiosurgery: ablative large dose of radiation in single fraction
(session) mostly for intracranial treatment
If more than 1 fraction and 5 or less fractions, its called
Stereotactic Body Radiotherapy (SBRT) OR Stereotactic
Ablative Radiotherapy (SABR)
a) 2D/3D/IMRT/VMAT
Brachytherapy

Stereotactic Radiosurgery- platforms
(machines)
Gamma knife Cyberknife

* The typical work flow of Radiation Oncologists:
See a new patient in the clinic or in the ward
Take a full history and perform physical examination
Order investigations
Discuss difficult cases in the tumor board (with colleagues from different specialties)
Discuss the treatment recommendations with the patient and his family
If radiation therapy to be given, prepare the patient and plan the radiation then deliver it and see
the patient while on treatment and afterward in a follow up.
Work-flow

Preparation
* Preparing the patient for radiation therapy:
Complete investigations
Get CT simulation scan/ MRI and or PET scan (CT in the treatment position)
On that scan, The radiation Oncology will draw the tumor and the adjacent important structures to
avoid (contouring)
Radiation planner will develop a plan (beams number, angles, directions etc)
Radiation physicist will check the plan before the radiation oncologist approves it.
After approval, the patient can start treatment
Radiation therapist position the patient and deliver the treatment every day

Preparation
CT simulation scan: requested by radiation
oncologist and performed by radiation
therapist
Contouring: by radiation oncologist
Planning: by physicist then reviewed and
approved by radiation oncologist
Treatment delivery: by radiation therapist

Cancer treatment definitions
* Timing of radiation therapy in relation with other therapies?
Neoadjuvant: when radiation is given before another curative treatment (usually
surgery).
Adjuvant: when radiation is given after anther curative (main treatment) usually surgery.
Concurrent: when radiation is given with chemotherapy at the same time.
* The purpose of the treatment:
Radical: when radiation alone is used to cure the cancer with or without chemotherapy
(concurrent chemo-radaition)
Palliative: when the goal of the treatment is to alleviate the symptoms in patient with
non-curative cancer

Examples
Examples of common curative treatmentType of cancer
Neoadjuvant radiation therapy + chemotherapy, then surgery.Rectal cancer
Surgery then adjuvant radiation treatment +/- chemotherapyBreast cancer
Radical radiotherapy or surgery then adjuvant
radiotherapy+chemotherapy or concurrent chemo+radiotherapy
Lung cancer
Radical radiotherapy: external beam or brachytherapy
Surgery then adjuvant radiotherapy if indicated
Prostate cancer
Concurrent chemo+radiationLymphoma

Not only cancers we treat
Common benign tumors that are treated with radiation therapy:
Meningioma, acoustic neuroma, ganglioma, desmoid tumor, pituitary tumors, etc
Example of some conditions (not tumors) that can be treated with radiation:
A.Trigeminal neuralgia.
B.Arteriovenous malformation (AVM) in the brain.
C.Some Psychiatric disorders (OCD, depression etc.
D.Essential tremor (movement disorder).
E.Dupuytren’s contracture

Common side effects
Common side effectsTumor site
Early: erythema, edema, soreness of skin
Late: skin dryness, darkness, arm lymphedema
Breast
Early: mild cough/SOB
Late: pneumonitis, fibrosis
Lung/chest
Early: diarrhea
Late: proctitis, rectal bleeding
Rectum
Early: skin changes, dry mouth, mucositis
Late: xerostomia, skin pigmentation, hoarseness, secondary malignancy
Head and neck
Early: H/A, N/V, fatigue
Late: somnolence syndrome, radiation necrosis, CN damage, secondary
cacner
Brain

Thank you!
Further inquiries
malghamdi1984@gmail.com

Radiation Oncology Speciality by Dr.Majed Alghamdi

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