Contouring, Etc Flashcards
Contraindications to breast conserving therapy
– Multicentric disease – Prior RT – Pregnancy – Positive margins (in breast tissue) – Collagen vascular disease – BRCA 1/2 mutation carriers
What kind of breast cancer is hard to detect on mammogram or ultrasound?
Lobular breast cancer since it is diffuse and not in a distinct mass; MRI is indicated if this is suspected; make sure to check the contra-lateral breast
Describe the neoadjuvant TCHP regimen
Taxotere 75mg/m2, Carboplatin AUC of 6, Herceptin at 6 mg/kg q3 weeks+ Pertuzumab 420mg q 3 weeks for 6 cycles
4 R’s of Radiotherapy are ….
Repair
- Normal cells repair better than cancer cells, fractionation allow for this repair.
Repopulation
- Tumor cells can repopulate when incompletely damaged, each fraction must kill more than the tumor’s ability to repopulate
Reassortment
-Each fraction allows tumor cells to re-assort into the M phase where the radiation damage occurs for double stranded breaks
Reoxygenation
- Cancer cells in tumor center less exposed to oxygen, which is necessary for indirect radiation damage through creation of superoxide radicals.
- Fractionation causes oxygen rich tumor cells to die off first, letting the central cells be re-oxygenated and more susceptible to radiation damage
Breast Dose Constraints
Hypofrac and Conventional (IMRT or 3DRT)
Protocol used:
Breast PTV eval:
Lumpectomy PTV eval:
- RTOG 1005: Phase 3 Trial of WBI (Hypofrac 40/15 + concurrent boost) vs (Conventional 50/25 or 42.7/16+ sequential) for early stage breast cancer
- Breast PTV eval (Hypofrac, Conventional):
V95 =38, 47.5 (95% of 40 Gy, 95% of 50 Gy)
V30 < 48, 62 (100% prescribed boost dose)
Dmax < 115% of max dose (WBI 40, 50 Gy) - Lumpectomy PTV eval (Hypofrac, Conventional):
V95 >45.6, 58.9 (95% of 48 Gy, 95% of 62 Gy)
V5 < 52.8, 68.2 (110% prescribed boost dose)
Dmax < 115% of max dose (WBI 48, 62 Gy)
Breast Dose Constraints
Hypofrac and Conventional (IMRT or 3D-CRT)
Protocol used: Heart: Ipsilateral lung: Contralateral lung: Contralateral breast:
- RTOG 1005: Phase 3 Trial of WBI (Hypofrac 40/15 + concurrent boost) vs (Conventional 50/25 or 42.7/16+ sequential) for early stage breast cancer
-Heart (Hypofrac, Conventional):
Mean dose < 4 Gy
V5 < 16, 20 (for left sided)
V0 < 16, 20 (for right sided)
- Ipsilateral lung (Hypofrac, Conventional):
V15 < 16, 20
V50 < 4, 5 - Contralateral lung (Hypofrac, Conventional):
V10< 4, 5 - Contralateral breast (Hypofrac, Conventional):
Dmax < 2.4, 3.1 Gy
V5 < 1.4, 1.8 Gy
APBI Indications
Suitable criteria:
Unsuitable criteria:
Suitable for
Age:
1) >= 50 y/o if patient has at least 1 of the pathologic factors below and does not have any “unsuitable” factors: 2.1-3 cm, T2, close marins <2 mm, limited/focal LVSI, ER negative, cliically unifocal, invasive lobular, pure DCIS < 3 cm, EIC < 3 cm
2) 40-49 if all other criteria for “suitable” are met
T stage: Tis or T1
DCIS: If all of following; screen-detected, grade 1-2, size <= 2.5 cm, margins >= 3 mm
Unsuitable for
Margins: Positive
DCIS >= 3 cm
Classic 2 Field Tangent Borders
Superior: Inferior: Medial: Lateral: Anterior:
Superior: 1 cm superior on the palpable breast tissue (inferior edge of sternoclavicular junction)
Inferior: 1 cm below the inframammary fold
Medial: At midline
Lateral: 1 cm margin on all breast tissue (will be at mid-axillary line to posterior axillary line)
Anterior: 2 cm flash on breast tissue
Paget’s disease presents with what symptoms?
Nipple crusting, bleeding, pruritis, ulceration
Indications for intraoperative PBI
ASTRO Consensus guidelines PRO 2016
- Counsel pts that 2 clinical trials show higher rates of IBTR ith IORT
Electron IORT restricted to invasive cancer with “suitable” criteria for PBI
Low energy X-ray IORT only in clinical trial, should also meet “suitable” APBI criteria
Fill in the blank:
Male breast cancers are ____ (more/less) likely to be ER positive than female breast cancers.
Cite a source.
Male breast cancers are MORE likely to be ER positive than female breast cancers.
MSK; Borgen, Ann of Surg Onc 1997; retrospective matched pair analysis. 87% male breast cancers were ER+ compared to 55% of female.
EORTC; Vermeulen, Eur J Cancer 2017; 1500 male breast patients, 99% luminal A or B
Fill in the blanks:
1) Patients with ____ (BRCA1/BRCA2) are more likely to present with triple negative disease.
2) Patients with ____ (BRCA1/BRCA2) are more likely to present with ER postive disease.
3) In patients with triple negative breast cancer ___% will be positive for a BRCA mutation. BRCA mutation is associated with ___% of all breast cancers total.
4) The lifetime risk of breast/ovarian cancers in ___ (BRCA1/BRCA2) carriers is 50-60% for both.
5) The lifetime risk of breast/ovarian cancers in ___ (BRCA1/BRCA2) carriers is 55% for breast, 15% for ovarian.
1) Patients with BRCA1 are more likely to present with triple negative disease.
2) Patients with BRCA2 are more likely to present with ER postive disease.
3) In patients with triple negative breast cancer 20% will be positive for a BRCA mutation. BRCA mutation is associated with 5% of all breast cancers total.
4) The lifetime risk of breast/ovarian cancers in BRCA1 carriers is 50-60% for both.
5) The lifetime risk of breast/ovarian cancers in BRCA2 carriers is 55% for breast, 15% for ovarian.
In NSABP B18; what percentage of nodes were positive at time of surgery for neoadj versus adj chemo arms?
Fisher et al 1997; neoadj AC ver adj AC
40% neoadjuv, 60% in adj arm N+ at time of surgery
PRIME II required what kind of surgical intervention?
CALGB 9343 required what kind of surgical intervention?
PRIME II - Lumpectomy with pathologic axillary staging (SLNBx or axillary dissection); Age > 65
CALGB 9343 - Lumpectomy +/- pathologic axillary staging; 60% did not have axillary staging; Age >70
In which trial was it reported that false negative rates for SLN Bx in low risk T1-2 cN0, and DCIS patients was 5-10%? (without use of dual tracer, clips etc)
Using what techniques in surgery can lower lower false negative rates? What studies show this?
Krag et al, Lancet Oncology 2007
Based off of NSABP-B32 data of early stage with cN0 disease to SLN Bx followed by ALND vs. SLN Bx alone with completion ALND only if nodes were positive.
- Use of dual tracer, clips, and taking more than 1 SLN
ACOSOG Z1071 for dual tracer, MD Anderson for clipped node at time of biopsy (decreased false negative rate to 2.4%)
