Transcript Intraoperative Radiation Therapy For Early Stage Breast Cancer

INTRAOPERATIVE
RADIATION THERAPY
FOR EARLY STAGE
BREAST CANCER
Miranda Pernaski
What is IORT?
Intraoperative Radiation Therapy
One time radiation treatment delivered immediately
following lumpectomy.
Radiation is only delivered to lumpectomy cavity including a
1-2cm margin
Sparing critical structures
• The idea of IORT first came about when a physician in
India wanted to treat women diagnosed with breast
cancer.
• Due to their cultural beliefs women were not capable to
drive themselves nor find a ride for weeks of treatment.
• J.S. Viadya thought of the idea of a one-time radiation
therapy treatment to eliminate this hassle for patients.
The IORT machines
Xoft Accent
Inflatable applicator head
Inflate until conformity to tumor cavity
HDR afterloading device
Applicator contains multiple catheters for the HDR
sources to travel through during treatment delivery
Zeiss Intrabeam
Solid spherical applicator head
Range in sizes from 2-5cm in diameter
Delivers uniform dose
Xoft Accent
Ziess Intrabeam
Patient Criteria for IORT
**Based off of ASTRO guidelines for breast brachytherapy procedures
• Early stage T0-T2
• Age
• Tumor size <3cm
• Negative margins after lumpectomy
• No nodal involvement
• Previous cancer and radiation therapy history
IORT Procedure
Observed procedure at Advocate Good Shepard
• Surgeon performs lumpectomy and sentinel node biopsy
• Confirms negative margins
• IORT device is placed within cavity (size of applicator head is
what fits best or surgeon’s preference)
• Breast tissue is loosely sutured up and around applicator
device to hold in place during treatment delivery
• Ultrasound is used to verify applicator head placement
-Must have at least 1cm margin of tissue around entire
head
• Treatment can then be delivered once everything is verified
• About 15-20 minute treatment time
• 20Gy delivered to lumpectomy cavity and 1-2cm margin
Background
Standard of care = EBRT following lumpectomy
• EBRT consists of 4-7 weeks of treatment
• 45-60Gy with or without boost
IORT = delivered immediately following lumpectomy
• One-time treatment
• 20Gy
IORT Treatment Delivery
• IORT delivers radiation to only tumor cavity and 1-2 cm
margin
• More critical structure sparing than EBRT
Contraindications of IORT
When a mastectomy is formed on a woman and the entire
breast is biopsied, microscopic tumor cells are found
throughout the entire breast.
**Original basis of EBRT to the entire breast tissue
The most prevalent site of breast cancer recurrence is
within a margin of the lumpectomy cavity.
**Basis for IORT
To Be Continued…
• Not enough long-term research to confirm overall benefit
compared to EBRT
• Future following of patients that have been treated is
needed