Follow-up/Toxicity Flashcards
What is the typical f/u schedule of pts treated for lung cancer?
Typical lung cancer f/u: H&P + CT chest with contrast q6–12 mos for 2 yrs, then noncontrast CT chest annually; continued smoking cessation counseling. PET or brain MRI is not routinely indicated. (per NCCN 2018)
What are the toxicities seen with SBRT for early-stage lung cancer?
Pneumonitis, lung fibrosis/consolidation, cough, dermatitis, CW pain, esophagitis, and hemoptysis
What is the total lung V20 dose–volume constraint for RT alone?
The total lung V20 dose–volume constraint is <35%. (per NCCN 2018)
What is the MLD constraint for definitive RT to lung cancer?
The MLD constraint is ≤20 Gy. (NCCN 2018)
What is the distinction b/t grade 2 and 3 RTOG pneumonitis?
Grade 2 pneumonitis: symptomatic with the need for steroids
Grade 3 pneumonitis: dyspnea at rest and oxygen supplementation needed
Other grades of pneumonitis include grade 1: asymptomatic, seen only on CT; grade 4: hospitalized and intubated; grade 5: death
What are the heart dose–volume constraints for conventionally fractionated RT?
Heart V40 ≤80%, V45 ≤60% and V60 ≤30%, mean ≤35 Gy. (NCCN 2018)
What is the dose constraint for the brachial plexus with conventional fractionation?
The max dose to the brachial plexus should be kept at ≤66 Gy. (NCCN 2018)
What is the rate of brachial plexopathy seen for pts treated with SBRT for early-stage lung cancer?
The recommended max dose to the brachial plexus is <26 Gy in 3–4 fx (Forquer JA et al., Radiother Oncol 2009). Of the 37 apical tumors for the 253 pts treated, 19% of pts developed grades 2–4 plexopathy. A dose >26 Gy resulted in 46% risk vs. 8% risk if the dose was <26 Gy.
At MDACC, for 70 Gy in 10 fx, max dose to the brachial plexus should be <60 Gy, ≤1 cc reaching 50 Gy and ≤10 cc 40 Gy. For 50 Gy in 4 fx, max dose to the brachial plexus should be <40 Gy, ≤1 cc, reaching 35 Gy and ≤5 cc 30 Gy.
At a min, what other normal tissue constraints should be closely examined during SBRT?
Location and size are important factors when considering normal tissue toxicity and constraints. Other tissues to monitor closely include esophagus, brachial plexus, trachea, main bronchus and bronchial tree, heart, total lung, major vessels, skin, CW, and SC.
What is the esophageal dose constraint for conventionally fractionated RT?
Ideally, the mean dose of RT to the esophagus should be ≤34 Gy and max ≤105% of Rx dose (per NCCN 2014). Try to minimize the V60 as much as possible (V60 <33%, V55 <66%, ≤45 Gy to the entire esophagus).
What is the max BED for SBRT resulting in significant complications when centrally located tumors were treated?
180–210 Gy with grade 3 pulmonary complications (Timmerman R et al., JCO 2006). Keeping the BED ≥100 Gy may be sufficient for LC and may avert toxicities for central lesions. (Onishi H et al., J Thorac Oncol 2007)
Is a normal SUVmax of FDG-PET required to be considered a good clinical response in the f/u of stage I NSCLC pts treated with SBRT?
No. Prospective and retrospective reviews suggest that the SUVmax remains elevated for an extended period after SBRT d/t an inflammatory response, but there is no evidence of correlation with recurrence. (Timmerman R et al., IJROBP 2009; Henderson MA et al., IJROBP 2009)
What % of pts treated with SBRT for early-stage lung cancer have grades 3–5 toxicities?
15% of pts have grades 3–5 toxicities in a review of 15 studies (683 pts). (Sampson JH et al., Semin Radiat Oncol 2006)
In RTOG 0236, 16.3% of pts experienced grades 3–4 toxicity but no grade 5 toxicity. (Timmerman R et al., JAMA 2010)
What factors predict for grades 3–5 toxicities after SBRT for early lung cancer seen on the Indiana University phase II study?
Location (46% hilar/pericentral vs. 17% peripheral) and tumor size (GTV >10 cc had 8 times the risk of grades 3–5 toxicity). (Timmerman R et al., JCO 2006)
What are the PFT changes before and after SBRT for early-stage lung cancer?
Very min based on an institutional review of 92 pts (Stephans KL et al., JTO 2009): mean FEV1 –0.05 (–1.88%), DLCO –2.59% of predicted value; no association with central vs. peripheral location or the dose administered.
