Quiz 4 Flashcards by Courtney W

RT is used in head and neck (H&N) treatments because _____ of the body’s LNs are in the H&N but sensitive organs are also in this area

1/3

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2 clinical presentations of H&N disease

Endophytic

Exophytic

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Growth pattern that invades within, more aggressive

Endophytic

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Noninvasive neoplasm that projects out from epithelium, usually presents with raised borders on skin

Exophytic

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4 diagnosis tools for H&N disease

Laryngoscopy
Palpation
Fiberoptic endoscopy
Biopsy

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Gingiva

Gums

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Triangular-shaped area behind molars

Retromolar trigone

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7 parts of the oral cavity

Lips
Buccal mucosa
Gingiva
Retromolar trigone
Hard palate
Floor of mouth
Anterior two thirds of tongue

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3 lymphatic drainage sites of the lips

Submandibular nodes
Preauricular
Facial nodes

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2 lymphatic drainage sites of the buccal mucosa

Submaxillary nodes

Submental nodes

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2 lymphatic drainage sites of the gingiva and retromolar trigone

Submaxillary nodes

Jugulodigastric nodes

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2 lymphatic drainage sites of the hard palate and anterior two thirds of the tongue

Submaxillary nodes

Upper jugular nodes

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2 lymphatic drainage sites of the floor of the mouth

Submaxillary nodes

Middle and upper jugular nodes

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4 parts of the oropharynx

Base of the tongue
Tonsillar fossa
Soft palate
Pharyngeal walls

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3 lymphatic drainage sites of the base of the tongue

Jugulodigastric nodes
Low cervical
Retropharyngeal nodes

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2 lymphatic drainage sites of the tonsillar fossa

Jugulodigastric nodes

Submaxillary nodes

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3 lymphatic drainage sites of the soft palate

Jugulodigastric nodes
Submaxillary
Spinal accessory nodes

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3 lymphatic drainage sites of the pharyngeal walls

Retropharyngeal nodes
Pharyngeal
Jugulodigastric nodes

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2 lymphatic drainage sites of the retropharyngeal nodes of the nasopharynx

Superior jugular nodes

Posterior cervical nodes

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2 lymphatic drainage sites of the sinuses

Retropharyngeal nodes

Superior cervical nodes

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3 parts of the larynx/voice box

Glottis
Subglottis
Supraglottis

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2 lymphatic drainage sites of the subglottis

Peritracheal nodes

Low cervical nodes

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3 lymphatic drainage sites of the supraglottis

Peritracheal nodes
Cervical submental
Submaxillary nodes

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Ear pain

Otaglia

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Don't know where cancer (CA) arose from, undifferentiated; treat like nasopharynx

Unknown primary

Pillar

Arch

Taste buds at back of tongue

Circumvallate papilla

"Spit trap"

Vallecula

4 H&N position and immobilization devices

Immobilization aquaplast mask: nose and zygomatic arches fit tightly but not on eyes; have minimal bolus effect and increase surface dose Bite block Arm stretcher Neck sponge: B or C head sponge

Keep tongue still or out of field

Bite block

Spinal cord of great concern at 4500 cGy; electrons posterior and photons anterior

Anterior triangles

2 H&N interstitial sources

Iridium | Iodine

Average head diameter and SSD

Diameter: 15 cm SSD: 92.5 cm

___-___ MV photons for oral cavity treatment

4-6 MV

Most common aerodigestive tract carcinomas

Oral cavity

Combined organs and tissues of respiratory tract and upper digestive tract including lips, mouth, tongue, nose, throat, vocal cords, and part of esophagus and windpipe

Aerodigestive tract

4 oral cavity maligancies

Tongue disease usually in lateral borders near middle or posterior 1/3 of tongue Floor of mouth or anterior surface any side of midline Lips and gum treated similar to skin CA Retromolar trigone, hard palate (rare), buccal mucosa, and gingival ridge

Gingival ridge

Gumline

Oral cavity superior and lower borders

Superior = skin-vermillion junction to posterior border of hard palate Down to circumvallate papillae/base of tongue

Where lips and skin connect

Skin-vermillion junction

Oral cavity opposed lateral and boost dose

Lateral: 4500 cGy Boost: 65-70 Gy

Oral cavity T3-T4 dose

Up to 80 Gy

Oral cavity IMRT dose to primary lesion

Over 2 Gy

Oral cavity superclav field dose

45-5000 cGy

Parotid TD5/5

3200 cGy

Level of oropharynx

C2-C3

5 disease sites of the oropharynx

``` Tonsils most common Base of tongue Lateropharyngeal walls Soft palate Uvula ```

Upper, anterior, inferior and posterior oropharynx borders

Upper: zygomatic arch, shield ear Anterior: clinically 2 cm beyond tumor Inferior: thyroid notch Posterior: cover cervical LNs

Initial dose, dose with posterior triangles, and dose with final boost for the oropharynx

Initial: 4500 cGy Posterior triangles: 6000 cGy Boost: 65-75 Gy

Higher dose per fraction to reduce number of weeks patient has to be treated

Accelerated

C3-C6, epiglottis to cricoid cartilage Lower posterior pharyngeal wall, posterior cricoid area, and pyriform sinuses IMRT and arcing field VMAT

Hypopharynx

Sinuses on either side of larynx

Pyriform sinuses

Preop and postop hypopharynx dose

Preop: 40-4500 cGy Postop: 60-65 Gy

Doesn't have direct drainage to LN chain and doesn't commonly metastasize

Larynx

Space between vocal cords, 65% of larynx CAs here

Glottis

Above vocal cords

Supraglottis

Below vocal cords

Subglottis

Treat larynx with ___x___ or ___x___ lateral or anterior oblique fields for early stage disease

5x5 or 6x6

Treat larynx with ___-___MV, ___cm of flash anteriorly

4-6MV | 1cm

Less than 200 cGy per fraction to larynx results in greater risk of recurrence; treat with over ___-___ cGy per fraction

200-225 cGy

BID larynx treatment dose and dose per fraction

7440-7900 cGy | 240 cGy per fraction

T1, T2, and T3 larynx disease dose

T1: 66 Gy T2: 70 Gy T3: 6850-7075 cGy (advanced disease)

Larynx superclav dose

46-50 Gy

Early stage larynx port superior, inferior, anterior, and posterior borders

Superior: top of hyoid bone Inferior: cricoid cartilage/lower border of C6 Anterior: 1-1.5cm flash/shine Posterior: early no LN cervical, anterior to vertebral body

Arytenoid

Cartilage

Lies at zygomatic arch to EAM, extends inferiorly down to mastoid tip behind nasal cavity above level of soft palate 3D and IMRT

Nasopharynx

Initial dose and boost dose for T1 and T2 nasopharynx disease

Initial: 5000 cGy T1: 6500 cGy T2: 70-75 Gy

Take similar skin to replace skin where disease caused it to be removed

Interoplation flap

Doesn't repair/regrow Don't often metastasize but are locally invasive and can create significant problems for patient Combined modality treatments: surgery, RT, and lipid soluble chemo to pass blood-brain barrier (BBB)

Central nervous system (CNS) malignancy

4 CNS treatment techniques

Radical surgery is the best chance for a good outcome Debulking surgery followed by RT to residual tumor that can't be completely excised, positive margins, or inaccessible tumor and metastatic lesions RT Stereotactic radiosurgery-Gamma knife

4 things RT dose for CNS disease depends on

Tumor type Grade Patterns of recurrence Radio-responsiveness

2 reasons whole-brain irradiation for CNS disease is done, setup like H&N treatments

Mets | Meningeal disease

3 layers of the meninges from inside out

Pia Arachnoid Dura mater

Curative CNS dose and palliative dose and number of treatments

Curative: 50-60 Gy Palliative: 30-3750 cGy in 10-15 treatments

Brain TD5/5

4500 cGy

Brainstem and posterior fossa dose and dose in fractions

5500-6000 cGy in fractions less than 200 cGy

Precision very important because high dose to small area, less fractions than SRT

Stereotactic radiosurgery (SRS)

SRS brain mets dose and fractions for small number of lesions (less than 4)

20-30 Gy in 1 fraction

SRS astrocytoma dose and fractions

1600-5000 cGy in 1-2 fractions

Usually nonmalignant bundle of vessels in brain, can cause strokes and is the leading cause of stroke in yound people

Arteriovenous malformation (AVM)

SRS AVM dose, radiation clogs vessels and they begin to deteriorate

20-25 Gy up to 12000 cGy

Cobalt and photon SRS without linac

Cobalt: gamma knife Photon: cyberknife

2 diseases craniospinal irradiations (CSI) are commonly used for in kids

Pediatric germinomas | Astroblastomas

Two opposed lateral fields for whole brain with spinal fields (1-2 depending on how long patient is) Prone and tilt chin up to avoid oral mucosa from PA spine field divergence

Craniospinal irradiation (CSI)

Overlapping spine field with whole brain treatments require us to do ______ and _______ rotation to match angle of divergence; overlapping PA spine fields require us to do __________ to avoid over radiating spinal cord

``` Couch, collimator Gap calculation (calc) ```

Rotate cranial field to match divergence from PA spinal field (SSD)

Collimator rotation

Rotate PA spine field to account for divergence from cranial fields (SAD)

Couch kick

CSI dose, dose for high risk recurrence patients, and boost to primary brain site

Dose: 3000 cGy High risk: 3600 cGy Boost: 5400-5580 cGy

Gap calc

(1/2)(L1)(d/SSD) + (1/2)(L2)(d/SSD)

Opposite over adjacent

Inverse tangent function (tan^-1)

Collimator angle formula

tan^-1(L1/SSD)

Couch kick formula

tan^-1(L1/SAD)

Migration of gap between treatment fields through treatment course; move junction on neck to reduce areas receiving radiation from overlap

Feathering

How far, at what dose, and what is the total dose that a CSI should be feathered?

Move 1 cm every 1000 cGy, total of 3000 cGy

5 CNS malignancies

``` Gliomas Medulloblastoma Craniopharyngioma Meningioma Lymphoma of the CNS ```

Pituitary gland dose and dose for tumors over 2cm

Dose: 45-5400 cGy | >2cm: up to 5400 cGy

2 digestive system malignancies

Colorectal | Pancreatic

Most common gastrointestinal malignancy, best prognosis

Colorectal

4 colorectal treatment techniques

Surgery: treatment of choice Adjuvant or neoadjuvant RT in conjunction with chemo Endocavitary RT/sphincter-preserving method/technique Chemo

Curative for patients with low to middle third rectal CAs, early stage disease confined to bowel wall Lidocaine relaxes sphincter, proctoscope inserted for doctor to see lesion; hose inserted and electrons administered Don't get deep dose with electrons

Endocavitary RT | Sphincter-preserving method/technique

Number of electron treatments with probe, dose per treatment, total dose, and time between treatments for endocavitary RT/sphincter-preserving method/technique

4 electron treatments at 3000 cGy = 12000 cGy total, treatments separated for 2 weeks

2 colorectal chemo regimens

5FU and leucovorin | FOLFOX

FOLFOX

5FU Leucovorin Oxiplatin

EBRT ___-___ weeks before endocavitary RT/sphincter-preserving method/technique which is given as a boost

7-8 weeks

___ colorectal cure rate with endocavitary RT/sphincter-preserving method/technique

90%

Colorectal dose and coned down dose

Dose: 4500 cGy Coned: 50-55 Gy

Small bowel (SB) TD5/5

40 Gy

Colorectal IMRT and VMAT dose for microscopic and gross residual disease (give higher dose because it's more conformal)

Microscopic: 60 Gy or more | Gross residual: 70 Gy or more

Colorectal treatment fields encompass ______________ and ______ with _______ field techniques or IMRT/VMAT

Primary tumor volume, LNs | Shrinking

2 LNs encompassed by colorectal treatment fields

Internal iliacs | Pre-sacrals

2 colorectal field arrangements determined by anterior structures and if they need dose (wedge with toes to AP and heels to PA)

AP/PA and 2 laterals | PA and 2 laterals

3 ways to get SB out of treatment field

Full bladder Stomach/belly board False tabletop

Linac in surgery, treat are with disease | Mobile accelerators that provide high energy electrons

``` Intraoperative RT (IORT) Precision therapy ```

IORT dose in single fraction to tumor bed

1000-1200 cGy

With 4 field colorectal treatments, _______ structures (bladder, etc.) receive more dose

2 multimodality esophageal CA treatment techniques

Surgery: superior/upper connected to oral cavity leading to decreased quality of life (QOL) Radiation and chemo: non-surgical treatment of choice; IMRT and VMAT boost

2 most common sites of esophageal disease

Middle esophagus | Distal esophagus

Most patients have locally advanced or metastatic esophageal disease leading to the use of ______ fields/portals because of potential for longitudinal spread

Large

Can see lesions 5cm from primary

Skip lesions

Upper esophageal treatment fields

2 anterior obliques

______ position is more comfortable but gravity can pull esophagus closer to spinal cord, ______ less comfortable but allows more distance between esophagus and spine

Supine, prone

Initial dose and dose per day to esophagus with AP/PA and obliques and first and second boost dose

Initial: 4500 cGy Per day: 180-200 cGy 1st: 5000 cGy 2nd: 60-70 Gy

Esophageal dose for just RT and no chemo and dose with RT and chemo

RT: 65 Gy Chemo: 50 Gy

Esophageal tumor infiltrates at tracheobronchial tree can lead to a fistula close to aorta that can rupture so we must lower the fractionated dose to _____cGy per day and use more fractions to still get close to total dose

150 cGy

2 pancreatic CA techniques

Surgery | RT and chemo preferred treatment for locally advanced or unresectable disease

Treatment of choice for pancreatic cancer Remove head of pancreas, duodenum, gallbladder, common bile duct, distal stomach, and possible vagotomy Can double median survival but most tumors are unresectable due to advanced disease

Whipple procedure

Most important diagnostic tool of pancreatic CA

4 field technique for pancreatic cancer; supine, arms above head

AP/PA and 2 laterals

6 dose limiting structures contained in the area of the pancreatic treamtent field

``` Liver Kidneys Heart Spinal cord SB Stomach ```

Liver, kidneys, heard, spinal cord, and stomach TD5/5

``` Liver: 3000 cGy Kidneys: 2300 cGy Heart: 4000 cGy Spinal cord: 4700 cGy Stomach: 5000 cGy ```

Pancreatic dose and dose per fraction; worry about kidneys on laterals

45-50 Gy at 180 cGy per fraction

AP and inferior pancreatic margins

AP: T11-L3, adequate margin; T12-L1 vessels Inferior: L2-L3, block kidneys

Pancreatic EBRT and IORT dose

EBRT first: 5040 cGy | IORT: 10-25 Gy (20 Gy)

3 gynecological malignancy

Uterine Cervix Endometrial

Fields for gynecological malignancies

4 field AP/PA and 2 laterals | Primary tumor and regional LNs

Distal end of anal canal forming a transitional zone between the epithelium of the anal canal and perianal skin

Anal verge

7 structures to worry about during the treatment of gynecological malignancies

``` Fleshy portion over pubis bone Clitoris Urethra meatus Labia major and minor Ovaries Cervix Endometrium ```

Obese patients whose large abdomen marks move a lot, stomach creates _______ and skin breakdown occurs under fold

Bolus

Will not treat over ______cGy if SB is in field

5000 cGy

Treatment for early stage (carcinoma in situ, 0, IA2) cervix disease based on involvement and treatment for childbearing

Total abdominal hysterectomy (TAH) and vaginal cuff | Conization

Inoperable early stage cervical disease in one implant with tandem and ovoids dose

45-55 Gy

Inoperable early stage cervical disease in one or two implants with tandem and ovoids dose for stage IA2

60-75 Gy

Initial EBRT dose for bulky/later stage cervix disease IIB3 and 4A; brachytherapy implant dose to low volume disease and bulky disease

EBRT: 40-50 Gy (45 Gy) Low volume: 70 Gy Bulky: 85-90 Gy

Ensure outer dose to cervical area with this block mounted in middle of AP/PA field allows dose to peripheral structures like LNs

Pogo Step wedge Midline block

Cervix superior, inferior, lateral, anterior, and posterior borders

Superior: AP/PA L4-L5 Inferior: BIT, BOF, or 4 cm below lowest extent of disease Lateral: 1.5-2 cm lateral of bony pelvis Anterior: lateral field anterior to symphysis pubis Posterior: transect sacrum at S3-S4

2 cm lateral to tandem and 2 cm superior to cervical oss or end of tandem, point where uterine vessels cross ureters (dose-limiting structure)

Point A

3 cm lateral to point A

Point B

1 cm lateral to point B

Point P

At point of foley catheter

Bladder

5 mm posterior to vaginal wall

Rectum

Lining of uterus

Endometrium

Stage IA, grade I (early stage) endometrial disease treatment

Hysterectomy only, encompassed in removed area

Stage IB, grade I, II endometrial disease post TAH brachytherapy dose

60-70 Gy or 5-7 Gy to 0.5 cm in three applications

Stage IC or higher, grade III endometrial disease post TAH external and implant dose

External: 45-50 Gy Implant: 80 Gy

Stage IC or higher, grade III endometrial disease post TAH 4 field dose, boost dose for gross involvement, and brachytherapy boost to endometrial cavity with Heyman capsules and tandem

4 field: 50-60 Gy Boost: 65 Gy Brachytherapy: 75-90 Gy

If hysterectomy, no tandem or Heyman capsules, use ______ and ________

Ovoids | Vaginal cylinder

Bladder and rectum TD5/5

Bladder: 6500 cGy Rectum: 6000 cGy

When treating endometrium, keep badder and rectum at this lower dose

60-75 Gy

Stage III, IV endometrial disease EBRT dose, brachytherapy dose, and bulky disease dose with shield

EBRT: 50 Gy Brachy: 75 Gy Bulky: 100 Gy

2 structures wing blocks during endometrial treatments decrease dose to

Bone marrow | Femoral heads

Post op whole abdomen EBRT dose and boost to paraaortic and pelvic LNs for ovarian disease

EBRT: 2550-3000 cGy Boost: 40-50 Gy

7 ways to increase anterior dose when treating vulva to minimize dose to femoral heads and rectum

Anterior weighting pulls dose anteriorly Lower anterior energy and high posterior energy pushes dose anteriorly Anterior electron field Anterior bolus Partial transmission blocks Narrow PA fields to protect femoral head and neck by closing in beam but may need to supplement inguinal LNs IMRT spares healthy tissue

External, treat with wide excision and EBRT Primary site and pelvic LNs Frog-leg to reduce bolus from folds and skin breakdown Wire scars/palpable nodes for gross disease and bolus over scar RT, surgery for recurrence

Vulva CA

Brachytherapy alone dose and EBRT first and brachytherapy dose for primary or macrodisease for vulva CA

Brachy: 60 Gy EBRT: 45-50 Gy, brachy: 65-80 Gy

Midline block when treating vulva after ___Gy for early invasive disease and after ___Gy for stages IIB or higher to get tumor dose to critical structures as close as possible

20 Gy, 40 Gy