Follow-up/Toxicity Flashcards
What is the typical recommended f/u schedule for pts treated for invasive BC?
Recommended f/u after Tx:
Interval H&P 1–4 times per yr × 5 yrs, then annually
Bilat mammogram annually, starting no sooner than 6 mos after completion of RT
Annual gyn exam for women with intact uterus on tamoxifen
Bone health assessment (bone mineral density scan) at baseline and periodically during course of use of AIs
For pts who have large breasts with large medial to lat separation (>22–24 cm), what techniques will improve dose homogeneity?
Photon energy >10 MV to keep max inhomogeneity <10% and field segmentation techniques. Avoid medial wedges to reduce scatter to contralat breast in pts <45 yo. Prone Tx can help, but RNI not possible in this position. Breast immobilization with molds (i.e., Aquaplast) can decrease skin toxicity to inframammary fold in the supine position.
What are the acute and late toxicities of whole breast RT?
Acute: RT dermatitis, fatigue, hyperpigmentation, pneumonitis
Late: ST fibrosis, breast size change, telangiectasias, lymphedema, pulmonary fibrosis, precocious cardiovascular Dz, 2nd malignancy
What randomized trials demonstrated the superiority of 3D-IMRT compared to 2D Tx approaches for minimizing cosmetic changes to the breast?
Royal Marsden (Donovan E et al., Radiother Oncol 2007) randomized 306 women to 2D-RT or 3D-IMRT. RT was 50 Gy → boost to 11.1 Gy with electrons. There was a significant cosmetic difference in the breast of 2D-RT (58%) vs. 3D-IMRT (40%) pts. Fewer pts in the IMRT group developed palpable induration. There were no differences in the QOL b/t the groups. A randomized trial (Pignol JP et al., JCO 2008) comparing breast IMRT with standard techniques showed IMRT to be sup with respect to moist desquamation (31% vs. 48%) and improved dose distribution.
What is the risk of 2nd malignancies in pts treated for early BC with RT?
From the WECARE study (Stovall M et al., IJROBP 2008), women <40 yo receiving >1 Gy to the contralat breast had an RR of 3. However, this excessive risk was not seen in pts >40 yo. Sarcomas (mostly angiosarcomas) within the RT field were <1% (∼10 cases in 10,000) within 10–30 yrs. (Taghian A et al., IJROBP 1991; Yap J et al., IJROBP 2002; Kirova YM et al., Cancer 2005)
What is the risk of lymphedema in pts treated for BC?
The risk of lymphedema is ∼5% after SLN dissection, and 10%–25% after level I–II axillary dissection. Comprehensive nodal RT after axillary dissection further increases the risk to 15%–35%. (Refer to a review by Erickson VS et al., JNCI 2001)
What is the risk of brachial plexopathy for a pt treated for BC?
Median time to developing brachial plexopathy is 10–12 mos (range 1.5–77 mos). It is dependent on RT dose and use of chemo. According to JCRT data (Pierce SM et al., IJROBP 1992), if the dose is kept at <50 Gy, the risk is <1% without chemo and ∼4.5% with chemo. If the dose is above 50 Gy, the risk is 5.6%.
What is the risk of cardiac toxicity, such as ischemic heart Dz after BCT for BC?
According to a population-based case-control study (Darby SC et al., NEJM 2013), rates of ischemic heart Dz are proportional to mean heart dose and increase linearly 7.4% per 1 Gy mean heart dose. Risk begins 1–2 yrs after RT and continues >20 yrs. Mean heart dose should be limited, and other cardiac risk factors should be managed.
What is the risk of pulmonary toxicities, such as lung fibrosis and symptomatic pneumonitis, after BCT for BC?
Pulmonary fibrosis occurs in everyone on imaging in the treated pleura, but clinical pneumonitis is rare. Data from the NCIC MA20 trial reported a rate of 0.2% pneumonitis after WBI and 1.2% with WBI + LN RT. (Whelan TJ et al., NEJM 2015)
