Particle therapy for clinically diagnosed stage I lung cancer: comparison with pathologically proven non-small cell lung cancer.
BACKGROUND
The purpose of the present study was to present the treatment outcomes of particle therapy for indeterminate pulmonary nodules (IPNs) diagnosed as stage I non-small cell lung cancer, including a comparative analysis involving pathologically proven lung cancer (PPLC).


METHODS
A total of 54 patients (57 lesions) who underwent particle therapy for IPNs were enrolled in this study. Median patient age was 76 (range 52-87) years. T-classification was: T1a, 30; T1b, 16; and T2a, 11. Particle therapy using protons or carbon ions was delivered at total doses of 52.8-80 Gy equivalent in 4-26 fractions. The PPLC cohort included 111 patients.


RESULTS
The median follow-up time was 41 (range 7-90) months. For all IPN patients, the three-year overall survival, progression-free survival, local control and distant progression-free survival rates were 90%, 72%, 94% and 79%, respectively. Grade 2 toxicities were radiation pneumonitis (19%), dermatitis (9%), rib fracture (2%), chest wall pain (2%) and neuropathy (2%). No ≥grade 3 toxicities were observed. In univariate analysis, the IPN group showed significantly better survival relative to the PPLC group. However, after adjustment for baseline imbalances between these two groups in multivariate analysis, pathological confirmation did not correlate with survival.


CONCLUSIONS
Particle therapy for IPNs provided favorable outcomes with minimal toxicities, which may be comparable to those for PPLC patients. Further studies are needed to clarify the optimal management of IPN patients.
Department of Radiology and Radiation Physics, Hyogo Ion Beam Medical Center , Tatsuno , Japan.
Osamu
O
Fujii
Yusuke
Y
Demizu
Naoki
N
Hashimoto
Masaru
M
Takagi
Kazuki
K
Terashima
Masayuki
M
Mima
Dongcun
D
Jin
Fumiko
F
Nagano
Kuniaki
K
Katsui
Tomoaki
T
Okimoto
Hiromitsu
H
Iwata
Yasue
Y
Niwa
Tomohiro
T
Yamashita
Takashi
T
Akagi
Takashi
T
Daimon
Ryohei
R
Sasaki
Yoshio
Y
Hishikawa
Mitsuyuki
M
Abe
Masao
M
Murakami
Nobukazu
N
Fuwa
D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis / Q000401:mortality / Q000473:pathology / Q000556:secondary / Q000601:surgery*; D002637:Chest Pain / Q000209:etiology; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D049268:Positron-Emission Tomography; D017564:Radiation Pneumonitis; D016634:Radiosurgery / Q000009:adverse effects / Q000379:methods*; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D012253:Rib Fractures / Q000209:etiology; D012272:Ribs / Q000293:injuries / Q000528:radiation effects; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome