radiation for cervix cancer

Robert Miller MDwww.aboutcancer.com

Cervix Cancer the Role of Radiation

Most common gynecologic cancers in women in 2012

Site Number

Breast 232,340

Uterus 49,560

Ovary 22,240

Cervix 12,340

Vulva 4,700

Median age at diagnosis for cancer of the cervix uteri was 49 years of age (uterus 61, ovary 63, vulva 68)

Lifetime risk is 0.66% or 1 in 151 of women born today will be diagnosed with cancer of the cervix

Stage Distribution 5 Year Survival

Local (confined site)

47% 91%

Regional (into nodes)

36% 57%

Distant (metastases)

12% 16%

• Avoidance of Human Papillomavirus Infection (abstinence, or condoms (lower risk by 60%)

• HPV16/18 vaccination will lower the risk by 92%

• Screening (pap smear) will lower incidence and mortality by 80%

• Smoking cessation (smoking cigarettes increases the risk in HPV+ women by 2 to 3 times)

Importance of screening because of disease progression

uterus

cervix

vagina

Spreading cancer

parametrium

Intovagina

Early Stage IA more advanced IA stage II

Work up or evaluation of a patient with cervix cancer before deciding on therapy

biopsy

Pathology Report• Invasive cancer or just dysplasia or in situ• Histology or type of cancer

• Squamous cancer (69%)• Adenocarcinoma (25%)

• Depth of invasion and lateral spread

Stages of Cervix Cancer

uterus

Cervix cancer

Stage I = confined to the cervix

IA = too small to see (found only on microscope)

IA1 = no deeper than 3mm or lateral than 7mm

IA2 = 3 to 5mm deep and lateral up to 7mm

IB = visible or bigger than a IA2

IB1 = up to 4cm IB2 = bigger than 4cm


Stage II = beyond the cervix

IIA = onto the upper vagina

IIA1 = up to 4cm

IIA2 = over 4cm

IIB = parametrial invasion



Stage IIIA = lower third vaginaStage IIIB = side wall or nodes +

Stage IVA = into bladder or rectumStage IVB = distant metastases

Cross section anatomy of the female pelvis

bladder

rectumcervix

Cross section anatomy of the female pelvis

rectum

vagina

rectum

PET Scan = Cervix Cancer

Cancer cells use more glucose or sugar and so “light up” on a PET scan which uses radioactive glucose

Lymph Nodesspread from the cervix

Frequency of lymph node metastases in cervical carcinoma.

Cervix cancer that has spread to para-aortic and pelvic nodes as seen on PET scan

Internal view (cross section) from PET

PET = Stage IIIB Cervix Cancer

Stage 5 Year Survival

IB 80%

IIA 63%

IIB 58%

III 30%

IVA 16%

Cervix Cancer Survival by Stage

Stage Survival SurvivalIA IA1 (97.5%) IA2 (94.8%)

IB IB1 (89.1%) IB2 (75.7%)

II IIA (73.4%) IIB (65.8%)

III IIIA (39.7%) IIIB (41.5%)

IV IVA (22%) IVB (9.3%)

Cervix Cancer Survival

NCCN.org

Treatment of cervix cancer

• Early stages: surgery (hysterectomy) or radiation

• More advanced cases: radiation +/- chemotherapy (cisplatin) then possibly surgery

Early Stages: Surgery or Radiation

More Advanced Stages: Radiation or Surgery

Indications for post-operative radiation and or chemotherapy based on pathology report after surgery

• Positive lymph node spread• Positive surgical margins• Invasion into the parametrium• Other high risk features:

• Large primary tumor• Deep stromal invasion• Lymphovascular invasion

Advanced Stages: Radiation plus Chemotherapy

5 Trials Demonstrating Improved Survival with Chemo-Radiation compared to

Radiation Alone

External Beam Radiation

Radioactive sourceApplicators

Internal Radiation

CT scan is obtained at the time of simulation

CT images are then imported into the treatment planning computer

In the simulation and treatment planning process the CT and PET scan images are used to create a “target” for the radiation and a computer plan is generated

During the treatment lasers are used to line up the beam and the patient receives the radiation treatment

External beam radiation is usually 5 to10 minutes, Monday though Friday, 5 days a week for 5 to 30 treatments

Normal structures identified on CT scans that can be affected by radiation and cause side effects

Normal Structures Identified on MRI

uterusuteruscervix cervix

vagina vagina

rectum rectum

bladderparametrium

Computer generated targets for IMRT Radiation for advanced cervix cancer to treat pelvis plus para-aortic lymph nodes

Combine a CT scan and linear accelerator to ultimate in targeting (IGRT) and ultimate in delivery (dynamic, helical IMRT) ability to daily adjust the beam (ART or adaptive radiotherapy)

Radiation for cervix cancers

• External beam irradiation (daily for 5 weeks) sometimes combined with chemotherapy (e.g. cisplatin)

• Low dose radiation (LDR) Internal radiation (radium or cesium implants, in hospital for 2-3 days

• High dose rate radiation (HDR) with Nucletron (Iridium) once a week for 3-5 weeks as an outpatient

Radiation Dose Techniques

• External beam 45Gy (40-50Gy) plus possible sidewall boost of 10-15Gy

• Brachytherapy: Point A total dose of 30-40Gy (LDR or 6Gy X 5 with HDR) to 80- 85Gy total dose

Internal radiation devices or brachytherapy

Internal radiation devicesTandem goes into the uterus

Ovoids go into the corners (fornices) next to the cervix

Internal Radiation Devices

HDR = high dose rate machine that can run radiation through a tube that reaches the patient through vaginal applicators

HDR Cervix Applicators

Internal radiation devices

Procedure can be performed in hospital and the patient stays over night using a Cesium isotope applicator or the procedure can be done as an outpatient with a faster technique (called high dose rate or HDR) using an Iridium isotope source (Iridium 192 with half life of 74 days)

Vaginal cylinder is inserted into the vagina, the radiation tube or wire stays inside the tube and doesn’t touch the patient’s skin

A Wire or Tube connects the vaginal or cervical applicators to the machine that holds the radioactive (Iridium) source

The woman lays on the radiation table and the treatment usually takes about 5 minutes and then the applicator is removed

Radiation Fields and Side Effects

Pelvic field

Para-aortic

Node field

Side Effects of Radiation are Related to Organs that are near the Cancer

Side Effects of Pelvic Radiation

ovary


Radiation may hit the bowel causing some more bowel frequency, cramps, diarrhea and fatigue

Radiation fields


Radiation fields

Radiation may hit the bladder and rectum causing urinary burning or frequency and rectal irritation as well as vaginal irritation

Patients may benefit from Imodium, cranberry juice, skin creams and rectal ointments

Long Term Side Effects of Pelvic Radiation

• Chronic bowel irritation (looseness or bleeding)• Chronic bladder irritation (more frequency or

burning)• Sexual dysfunction (more vaginal dryness or

fibrosis)• Ovarian dysfunction (normal pelvic radiation doses

to the ovaries will cause menopause)• Osteitis of the bone (more brittle bones)

Robert Miller MDwww.aboutcancer.com

Cervix Cancer the Role of Radiation

radiation for cervix cancer

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