Immobilization and daily treatment setup for Prone Breast Radiotherapy is always challenging for radiation therapist team. This presentation will highlights the possibilities of the different immobilization and setup approaches in therapist perspective.
Immobilization and setup for Prone Breast Radiotherapy- A Therapist approach
1. Immobilization and setup for Prone Breast
Radiotherapy- A Therapist approach
Teekendra Singh Faujdar
Sr. Radiation Therapist,
Medanta The-Medicity, Gurgaon.
2. Epidemiology
• Most common cancer in women worldwide.
• Second leading cause of cancer death among women after lung cancer
• Yearly ~40,000 women die of Breast Cancer.
• More than three fourths of these women in developing countries are
diagnosed in advanced stage of the disease. If these lesions are detected early,
most breast cancers can be effectively treated with good outcome.
• Lifetime risk of dying from Breast Cancer 3.4%
3. Breast cancer incidents in India
In India 144,937 women were newly detected with breast cancer in 2012, of which 70,218 women died.
Roughly, for every 2 women newly diagnosed with breast cancer in India, one dies of this disease.
5. Treatment
Two major treatment options
– Mastectomy
– Breast conserving therapy
– Margin-negative lumpectomy
– Adjuvant radiation therapy
• Adjuvant therapy
– Dependent on pathologic variables
– Chemotherapy
– Hormonal therapy
6. Breast- Clinical Borders
• Clinical Borders of Breast
• Medial: Sternum
• Lateral: Mid axillary line
• Cranial: 2ndRib
• Caudal: 6thRib
• Most Breast Cancers are located in the upper
outer quadrant of the breast
• Greatest Percentage of breast tissue Left sided
breast cancers are more common
7. RTOG 1005 & 1304; Organs at Risk
• Heart
• Left Lung
• Right Lung
• Contralateral Breast
• Sternum
• Thyroid
8. Rationale for Radiation
• Role of radiation in the setting of breast conservation and
post mastectomy:
– Improvement in local or loco-regional control
– Survival benefit in invasive carcinomas and in
the post mastectomy setting
• Disease free survival
• Overall survival
10. Radiation Treatment Options
DOSE and FRACTIONATION
Target the entire breast
• Dose of 45-50.4 Gy to whole breast
• 1.8-2 Gy per fraction
• Electron boost to tumor cavity
• 10-16 Gy
• 6 ½ weeks of treatment
12. Radiation Treatment Options
TECHNIQUES:
– CT simulation and volume based planning
– 3D conformal, IMRT, VMAT, TOMO
– Respiratory control with deep inspiration breath hold
technique
• “respiratory gating”
– Positioning
• Supine v/s Prone
13. Rationale Supine v/s Prone in Breast Radiotherapy
• Radiotherapy for WBI in the supine
position is standard
• Large, pendulous breasts can be
problematic
-Displacement of breast laterally, inferiorly
-Accentuation of the infra-mammary folds
• Excessive lung & heart included in some
cases
• Contour extends beyond CT field-of-view
14. Large Patient BMI: Technical Challenge for
Radiotherapy
Irradiation of skin folds: -Moist Desquamation
-Skin reactions
15. Indications for Prone Breast Radiotherapy
• Patients with larger BMI and/or
pendulous breasts to reduce the
toxicity and improve breast
appearance long term
• Left sided breast cancer patients
to avoid the heart & lung
• Small Breast benefits due to
decrease in lung dose
• Cases where maximal lung
avoidance is desirable such as
smokers, severe COPD (Chronic
Obstructive Pulmonary Disease)
Kirby et al. RadiotherOncol96: 178-84, 2010.
Bartlett et al. RadiotherOncol114: 66-72, 2015
17. Setup & Positioning
• Index Immobilization
• Contra breast should be gently pulled “down & out”
• Head turned toward the contra side
• Back should be as flat as possible with shoulders relaxed
Improves set-up of contralateral breast
19. Patient Selection for Prone
• Need to be able to get into the prone position and maintain
stable position
– Arm and neck range of motion
– Back pain
– Agility and flexibility
– Respiratory status
– Performance status
• Asking the patient about she tolerated prior biopsy procedure and / or MRI can be
helpful
20. Indications for Prone Breast Radiotherapy
• Better dose homogeneity
due to smaller separation
• Reduces skinfolds
• Distances the breast from
the chest-wall
• Reduction in chest-wall
Motion
• Reduction of scatter to
opposite breast
EBCTCG. Lancet378(9804): 1707-16, 2011.
21. THE PRONE POSITION: IMPROVING
COSMETIC OUTCOMES
• When the patient is lying prone, it allows for the breast to fall away from the chest
wall which opens up the infra-mammary fold, as well as lateral skin folds, which
can ultimately eliminate the bolus effect that would be experienced in the supine
position.
• Bergom et al found that only 4.5 percent of their patients treated prone experienced
Grade 3 skin reactions
– When they compared their prone positioning outcomes with a previous supine
positioning study, they concluded the prone position offers good and/or excellent
cosmetic outcomes in 22 to 36 percent more patients when treated in the prone versus
supine position.
– Bergom C, et al. International Journal of Radiation Oncology, Biology, and Physics. January 2011;83
22. THE PRONE POSITION: LIMITING
DOSES TO CRITICAL STRUCTURES
• Lymberis et al, found that the prone position was better than the supine position in all patients
for sparing the ipsilateral lung as the dose was 4.04 Gray (Gy) less than the supine position.
• He also found the prone position was optimal for left sided breast cancer patients 87 percent of
the time because it spared the in-field heart volume.
• Lymberis S, et al, International Journal of Radiation Oncology, Biology, and Physics. 2012;84(4):902-909
• Varga et al, had similar findings as they reported a difference of 5.43 Gy in the prone versus
supine position.
• Varga Z et al, International Journal of Radiation Oncology, Biology, and Physics. September 2009;75(1):94-100
• The reason the dose is able to be reduced so drastically is because the average volume of lung
irradiated in the prone position is 103.6 cubic centimeters less than in the supine position.
• Lymberis S, et al, International Journal of Radiation Oncology, Biology, and Physics. 2012;84(4):902-909
23. THE PRONE POSITION: IMPROVING
DOSE INHOMOGENEITY
• Dose Inhomogeneity leads to an increased risk of long-term edema and fibrosis in
the areas of the breast which receive a higher dose.
• If the patient is lying prone, it allows for the breast to lengthen anteriorly causing it
to narrow the contour which can ultimately provide a more even dose distribution
throughout the breast.
» McKinnon R, Christie D, Peres H, et al. The prone technique for breast The Breast. February 2009;18(1)
• Veldeman et al, compared both positions and found dose inhomogeneity to be 13.9
percent in the prone position and 15.1 percent in the supine position.
• While this is not a large discrepancy between the two positions, it does show that the prone position
can offer slightly more homogenous doses to the target volume in breast radiotherapy.
» Veldeman L, et al. International Journal of Radiation Oncology, Biology, and Physics. April 2012;82
24. THE PRONE POSITION: IMPROVING
INTRA/INTER-FRACTION SETUP
VARIATIONS
• Morrow et al found that chest wall motion during treatments to be 2.4
millimeters greater in the supine position as compared to the prone position
– Morrow N, et al. Intra- International Journal of Radiation Oncology, Biology, and Physics. November 2007;69
• Kirby et al, supports this as they found average chest wall motion to be 2.8
millimeters in the prone position compared to 3.4 millimeters in the supine
position.
– Kirby A, Radiotherapy & Oncology. August 2011;100(2):221-226. doi:10.1016/j.radon.2010.11.005.
• These results are consistent with the thorax essentially being immobilized
against the platform in the prone position.
• Reproducibility in the prone position does appear to be more challenging, but it
is achievable as the average inter-fractional motion remains acceptable.
25. THE PRONE POSITION: WHEN IT
DOES NOT WORK
• While the prone position offers optimal treatment outcomes in many
instances, there are some situations in which the supine position is
required such as:
– Patients requiring irradiation of the chest wall
– A tumor bed that lies deep and posterior in the breast
– Lymph node coverage
• When supraclavicular nodes are involved, it is evident why the prone position would
not be an option due to this area being inaccessible.
– Electron boosts due to the difficult accessibility of the scar
• In these instances, the supine position would be required and factors
such as acute and late toxicities would unfortunately need to be
sacrificed.
26. THE FUTURE OF PRONE POSITIONING
IN BREAST RADIOTHERAPY
• To provide the best care for all patients regardless of their treatment
requirements, it would be worthwhile to investigate alternative delivery
methods such as intensity modulated radiation therapy and image guided
radiation therapy.
• These techniques can be applied to the prone position to further improve its
outcomes as well as to the supine position when it is necessary for certain
patients.
• The goal of these newer modalities is to further reduce the dose to critical
structures and ultimately late toxicities of treatment.
• Although traditional prone positioning significantly improves outcomes,
conducting further research among newer treatment techniques can lead to
additional advancements in breast radiation therapy.
27. Key Components for Successful Prone
Treatments
• Integrated Team of Specialists
• Full Patient Compliance and Understanding
• Proper Equipment
• Established Policy & Procedure
28. References1. Breast cancer. American Cancer Society Web site. http://www.cancer.org/cancer/breastcancer/index. 2013. Accessed February 9,
2013.
2. Lymberis S, deWyngaaert J, Parhar P, et al. Prospective assessment of optimal individual position (prone versus supine) for
breast radiotherapy; volumetic and dosimetric correlations in 100 patients. International Journal of Radiation Oncology, Biology,
and Physics. 2012;84(4):902-909. doi:10.1016/j.ijrobp.2012.01.040.
3. Stegman L, Beal K, Hunt M, Fornier M, McCormick B. Long-term Clinical Outcomes of Whole-Breast Irradiation Delivered in
the Prone Position. International Journal of Radiation Oncology, Biology, and Physics. May 2007;68(1): 73-81.
doi:10.1016/j.ijrobp.2006.11.054.
4. McKinnon R, Christie D, Peres H, et al. The prone technique for breast irradiation – is it ready for clinical trials? The Breast.
February 2009;18(1):30-34. doi:10.1016/j.breast.2008.96.006.
5. Veldeman L, Speleers B, Bakker M, et al. Preliminary results on setup precision on prone-lateral patient positioning for whole
breast irradiation. International Journal of Radiation Oncology, Biology, and Physics. September 2010;78(1):111-118.
doi:10.1016/j.ijrobp.2009.07.1749.
6. Morrow N, Stepaniak C, White J, Wilson JF, Li XA. Intra- and interfractional variations for prone breast irradiation: an
indication for image-guided radiotherapy. International Journal of Radiation Oncology, Biology, and Physics. November
2007;69(3):910-917. doi:10.1016/j.ijrobp.2007.06.056.
7. Bergom C, Kelly T, Morrow N, et al. Prone Whole-Breast Irradiation Using Three-Dimensional Conformal Radiotherapy in
Women Undergoing Breast Conservation for Early Disease Yields High Rates of Excellent to Good Cosmetic Outcomes in Patients
With Large and/or Pendulous Breasts. International Journal of Radiation Oncology, Biology, and Physics. January 2011;83(3):
821-828. doi: 10.1016/j.ijrobp.2011.08.020.
8. Varga Z, Hideghety K, Mezo T, et al. Individual positioning: a comparative study of adjuvant breast radiotherapy in the prone
versus supine position. International Journal of Radiation Oncology, Biology, and Physics. September 2009;75(1):94-100.
doi:10.1016/j.ijrobp.2008.10.045.
9. Kirby A, Evans P, Helyer S, Donovan E, Convery H, Yarnold J. A randomised trial of supine versus prone breast radiotherapy
(SuPr study): comparing set-up errors and respiratory motion. Radiotherapy & Oncology. August 2011;100(2):221-226.
doi:10.1016/j.radon.2010.11.005.
10. Veldeman L, De Gersem W, Speleers B, et al. Alternated prone and supine whole-breast irradiation using IMRT: setup
precision, respiratory movement, and treatment time. International Journal of Radiation Oncology, Biology, and Physics. April
2012;82(5):2055-2064. doi:10.1016/j.ijrobp.2010.10.070.
11. Algan O, Fowble B, McNeeley S, Fein D. Use of the prone position in radiation treatment for women with early stage breast
cancer. International Journal of Radiation Oncology, Biology, and Physics. March 1998;40(5):1137-1140.