Breast Cancer

Ch.34 Washington & Leaver Radiation Therapy

(Suggested Tolerance Doses -QUANTEC) Heart

V25 < 10%

According to the RTOG Breast Cancer Atlas, the contour of the Breast CTV should include the

A. apparent glandular tissue and axillary lymph node regions.

B. apparent glandular tissue and tissue outlined by conventional anatomic markers. C. lumpectomy GTV, including the surgical scar.

D. lumpectomy CTV + 1 cm margin.

B. apparent glandular tissue and tissue outlined by conventional anatomic markers

An ipsilateral fibrotic lung lesion resulted after electron arc for breast cancer. The most probable cause is:

A. a new metastatic lesion.

B. improper dosage.

C. incorrectly chosen energy.

D. concentrated bremsstrahlung dose.

D. concentrated bremsstrahlung dose

Which breast quadrant has the highest incidence of breast cancer?

A. Lower inner
B. Upper outer
C. Lower outer
D. Upper inner

B. Upper outer

Most breast cancers originate in which anatomical structure?

A. Lobules
B. Stroma
C. Ducts
D. Internal mammary nodes

C. Ducts

A lymph node located between the pectoralis major and minor muscles is known as:

A. Level I node
B. Level III node
C. Rotter’s node
D. Sentinel node

C. Rotter’s node

Axillary nodes that lie below the pectoralis minor muscle are classified as:

A. Level I
B. Level II
C. Level III
D. Internal mammary nodes

A. Level I

Which pathology represents non-invasive breast cancer?

A. Infiltrating ductal carcinoma
B. Infiltrating lobular carcinoma
C. Ductal carcinoma in situ
D. Inflammatory carcinoma

C. Ductal carcinoma in situ

Which feature is associated with poor local control after breast-conserving treatment?

A. Tumor size <2 cm
B. Age >60
C. Failure to use radiation when indicated
D. Negative margins

C. Failure to use radiation when indicated

Traditional breast tangent prescription following lumpectomy is:

A. 26–27 Gy in 5 fractions
B. 21.9 Gy in 3 fractions
C. 50.4 Gy with boost to 60 Gy
D. 34 Gy in 10 HDR fractions

C. 50.4 Gy with boost to 60 Gy

Which of the following is not typically a reason for mastectomy over lumpectomy + RT?

A. Desire to avoid 5–7 weeks of RT
B. Tumor > 5 cm
C. Poor follow-up ability
D. Stage 0 DCIS, clear margins

D. Stage 0 DCIS, clear margins

Internal mammary nodes are located approximately how deep?

A. 1 cm
B. 2 cm
C. 3 cm
D. 6–8 cm

C. 3 cm

Which field arrangement requires 10–15° angulation to avoid spinal cord and esophagus dose?

A. Tangents
B. Internal mammary
C. Posterior axillary boost
D. Supraclavicular field

D. Supraclavicular field

Use of bolus post-mastectomy is most appropriate for:

A. Standard intact breast irradiation
B. Positive margins or recurrent disease
C. LCIS treated with lumpectomy
D. DCIS with clear margins

B. Positive margins or recurrent disease

A posterior axillary boost is added to:

A. Reduce lung dose
B. Improve dose to deep axillary nodes
C. Spare the brachial plexus
D. Cover internal mammary chain

B. Improve dose to deep axillary nodes

Which constraint aligns with QUANTEC lung guidance for breast treatment?

A. Mean lung <30 Gy
B. V20 <30–35%
C. V25 <10%
D. Brachial plexus max <66 Gy

B. V20 <30–35%

(Lung mean <20-23 Gy, V20 <30-35%)

Which systemic therapy is used for HER2+ breast cancers?

A. Tamoxifen
B. Aromatase inhibitors
C. Herceptin
D. Methotrexate

C. Herceptin

Clinical Scenario: A 52-year-old woman undergoes lumpectomy for a 2.1 cm IDC, 0/5 nodes, clear margins. No skin involvement. Appropriate RT approach?

A. Mastectomy alone
B. Tangents to 50.4 Gy + boost to 60 Gy
C. HDR brachytherapy 45–50 Gy primary treatment
D. Treat with bolus daily

B. Tangents to 50.4 Gy + boost to 60 Gy

Following lumpectomy, radiation therapy is given primarily to:

A. Reduce systemic recurrence
B. Sterilize microscopic residual disease
C. Reduce chemotherapy toxicity
D. Treat contralateral breast

B. Sterilize microscopic residual disease

A patient with 6 positive axillary nodes is post-mastectomy. RT is:

A. Not indicated
B. Indicated due to ≥4 positive nodes
C. Only needed if tumor <2 cm
D. Required only if DCIS

B. Indicated due to ≥4 positive nodes