Challenges scoring radiation pneumonitis in patients irradiated for lung cancer.
OBJECTIVE
To quantify uncertainties in scoring radiation pneumonitis.


METHODS
Records of 434 patients irradiated for lung cancer from 2000 to 2010 were retrospectively reviewed; IRB-approved study. From these, 121 received ≥ 60 Gy for non-small cell lung cancer (NSCLC) with ≥ 6 months follow-up. Patients where the physicians were uncertain of the diagnosis due to confounding factors were deemed "hard to score". Subgroups were defined based on lung dosimetric parameters, and frequencies in different subgroups were compared via Fisher's exact test.


RESULTS
21/121 of patients were considered to have pneumonitis; median follow 17 months. Of these, 10/21 were "hard to score"; reasons including acute COPD exacerbation, infection, and tumor progression. "Hard to score" pneumonitis was slightly more common in patients with a COPD history (15%) vs. without COPD (4%) (p=0.05); and with a pre-RT FEV1<1.7 L (16%) vs. ≥1.7 L (4%) (p=0.09). Rates of "unambiguous" pneumonitis trended to be non-significantly slightly higher in patients higher mean lung doses, V5, and V30.


CONCLUSIONS
Radiation pneumonitis occurred in 17% of patients undergoing RT for NSCLC; with diagnostic uncertainty in 48% of these. Poor pre-RT pulmonary function increases the rate of "hard to score" pneumonitis. Dosimetric parameters are slightly better related to "unambiguous" than "hard to score" pneumonitis, as expected.
Departments of Radiation Oncology, University of North Carolina, Chapel Hill, NC 27599-7512, USA.
Eda
E
Yirmibesoglu
Daniel S
DS
Higginson
Merdan
M
Fayda
M Patricia
MP
Rivera
Jan
J
Halle
Julian
J
Rosenman
Liyi
L
Xie
Lawrence B
LB
Marks
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000150:complications* / Q000473:pathology / Q000532:radiotherapy; D005260:Female; D006801:Humans; D015994:Incidence; D008175:Lung Neoplasms / Q000150:complications* / Q000473:pathology / Q000532:radiotherapy; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D017564:Radiation Pneumonitis / Q000175:diagnosis* / Q000453:epidemiology; D011879:Radiotherapy Dosage