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Background: Lung cancer is frequently complicated by interstitial lung disease (ILD). Treatment protocols for lung cancer patients with ILD have not been established; surgery, chemotherapy, and radiotherapy can all cause acute exacerbation of ILD. This study evaluated the toxicity and efficacy of carbon ion radiotherapy (CIRT) in patients with non-small cell lung cancer (NSCLC) and ILD.Methods: Between June 2004 and November 2014, 29 patients diagnosed with NSCLC and ILD were treated with CIRT. No patient was eligible for curative surgery or conventional radiotherapy secondary to ILD. Owing to prior symptomology, radiation pneumonitis (RP) and symptom progression pre- and post-treatment were evaluated. The relationships between RP and clinical factors were investigated.Results: Twenty-eight men and one woman, aged 62 to 90 years old, were followed for 2.7-77.1 months (median: 22.8 months). Single-grade symptomatic progression (grade 2-3) was observed in 4 patients, while 1 patient experiencedtwo-grade progression. Two patients experienced radiation-induced acute exacerbation. Local control at 3 years was 63.3% (72.2% for stage I disease); survival at 3 years was 46.3% (57.2% for stage I disease). Eighteen patients had died by the time of this writing, 10 of lung cancer progression. Radiation pneumonitis post-treatment progression correlated with dosimetric factors of the lungs (V5, V10) and a low pre-treatment serum surfactant protein-D.Conclusions: We found that CIRT may be useful as a low-risk, curative option for NSCLC patients with ILD, a population that is typically ineligible for conventional therapy. The DVH analysis showed that minimizing the low-dose region is important for reducing the risk of severe RP.Trial Registration: NIRS-9404 . Registered 1 March 1994. [ABSTRACT FROM AUTHOR]

Background: Carbon-ion radiotherapy (CIRT) is a promising treatment for locally advanced non-small-cell lung cancer, especially for patients with inoperable lung cancer. Although the incidence of CIRT-induced radiation pneumonitis (RP) ≥ grade 2 ranges from 2.5 to 9.9%, the association between CIRT-induced RP and dosimetric parameters is not clear. Herein, we identified prognostic factors associated with symptomatic RP after CIRT for patients with non-small-cell lung cancer.Methods: Clinical results of 65 patients treated with CIRT between 2000 and 2015 at the National Institute of Radiological Sciences were retrospectively analyzed. Clinical stage II B disease (TNM classification) was the most common stage among the patients (45%). The median radiation dose was 72 Gy (68-76) relative biological effectiveness (RBE) in 16 fractions. In cases involving metastatic lymph nodes, prophylactic irradiation of mediastinal lymph nodes was performed at a median dose of 49.5 Gy (RBE). The median follow-up was 22 months.Results: Grade 2 and grade 3 RP occurred in 6 and 3 patients (9 and 5%), respectively. No patients developed grade 4 or 5 RP. Using univariate analysis, vital capacity as a percentage of predicted (%VC), forced expiratory volume in 1 s (FEV1), mean lung dose (MLD), volume of lung receiving ≥5 Gy (RBE) (V5), V10, V20 and V30 were determined to be the significant predictive factors for ≥ grade 2 RP. The receiver operating characteristic (ROC) analysis revealed the cutoff values for %VC, FEV1, MLD, V5, V10, V20 and V30 for ≥ grade 2 RP, which were 86.9%, 1.16 L, 12.5 Gy (RBE), 28.8, 29.9, 20.1 and 15.0%, respectively. In addition, the multivariate analysis revealed that %VC <86.9% (odds ratio = 13.7; p = 0.0041) and V30 ≥ 15% (odds ratio = 6.1; p = 0.0221) were significant risk factors.Conclusions: Our study demonstrated the risk factors for ≥ grade 2 RP after carbon-ion radiotherapy for patients with locally advanced lung cancer. [ABSTRACT FROM AUTHOR]

OBJECTIVES: Carbon ion radiotherapy (CIRT) has been expected to be an alternative for surgery for early-stage non-small-cell lung cancer (NSCLC) and adopted as the second-best choice even in operable patients although local recurrence after CIRT is sometimes experienced. The purpose of this study was to investigate the demographic data, perioperative courses and therapeutic outcomes of patients who underwent salvage resection for local recurrence after CIRT. METHODS: From November 1994 to February 2012, CIRT was applied for 602 c-T1/T2/T3N0M0 NSCLC lesions of 599 patients at the National Institute of Radiological Science. A total of 95 (16%) patients were diagnosed as having local recurrence, of whom 12 underwent salvage surgeries. The medical records were retrospectively reviewed. RESULTS: There were 7 men and 5 women (mean age, 63 ± 7.4 years). The clinical stages upon initial presentation with NSCLC were as follows: 4 IA, 7 IB and 1 IIB. All the patients were operable, but refused surgery and underwent CIRT. The median progression-free survival time after CIRT was 20 months (range, 7.1-77 months), and salvage surgery was performed at a median of 24 months (range, 9-78 months) after CIRT. All surgeries were successfully performed without any significant CIRT-related adhesions during the surgery, resulting in no mortality or Clavien-Dindo grade 3-4 postoperative complications. However, the distribution of pathological stages was as follows: 4 IA, 3 IB, 2 IIB, 2 IIIA and 1 IV, which included 6 upstages from the clinical stages before CIRT. The Kaplan-Meier estimate of overall survival after the salvage surgery showed that the 3-year survival rate was 82%. CONCLUSIONS: The dose intensity of CIRT spared the hilum of the lungs and parietal pleura, none of the patients developed adhesions outside of the radiation field, such that the salvage surgeries for local recurrence after CIRT were safe and feasible. [ABSTRACT FROM AUTHOR]

Background: To moving lung tumors, we applied a respiratory-gated strategy to carbon-ion pencil beam scanning with multiple phase-controlled rescanning (PCR). In this simulation study, we quantitatively evaluated dose distributions based on 4-dimensional CT (4DCT) treatment planning. Methods: Volumetric 4DCTs were acquired for 14 patients with lung tumors. Gross tumor volume, clinical target volume (CTV) and organs at risk (OARs) were delineated. Field-specific target volumes (FTVs) were calculated, and 48Gy(RBE) in a single fraction was prescribed to the FTVs delivered from four beam angles. The dose assessment metrics were quantified by changing the number of PCR and the results for the ungated and gated scenarios were then compared. Results: For the ungated strategy, the mean dose delivered to 95% of the volume of the CTV (CTV-D95) was in average 45.3 ± 0.9 Gy(RBE) even with a single rescanning (1 × PCR). Using 4 × PCR or more achieved adequate target coverage (CTV-D95 = 46.6 ± 0.3 Gy(RBE) for ungated 4 × PCR) and excellent dose homogeneity (homogeneity index =1.0 ± 0.2% for ungated 4 × PCR). Applying respiratory gating, percentage of lung receiving at least 20 Gy(RBE) (lung-V20) and heart maximal dose, averaged over all patients, significantly decreased by 12% (p < 0.05) and 13% (p < 0.05), respectively. Conclusions: Four or more PCR during PBS-CIRT improved dose conformation to moving lung tumors without gating. The use of a respiratory-gated strategy in combination with PCR reduced excessive doses to OARs. [ABSTRACT FROM AUTHOR]

Background The purpose of this study was to evaluate the efficacy and feasibility of carbon ion radiotherapy (CIRT) for oligo-recurrent lung tumors from colorectal cancer (CRC). Methods From May 1997 to October 2012, 34 consecutive patients with oligo-recurrent pulmonary metastases from CRC were treated with CIRT. The patients were not surgical candidates for medical reasons or patient refusal. Using a respiratory-gated technique, carbon ion therapy was delivered with curative intent using 4 coplanar beam angles. A median dose of 60 GyE (range, 44-64.8 GyE) was delivered to the planning target volume (PTV), with a median daily dose of 15 GyE (range, 3.6-44 GyE). Treatment outcome was analyzed in terms of local control rate (LCR), survival rate, and treatment-related complications. Results In total, 34 patients with 44 oligo-recurrent pulmonary lesions were treated with CIRT. Median follow-up period was 23.7 months. The 2- and 3-year actuarial LCRs of the treated patients were 85.4% ± 6.2% and 85.4% ± 6.2%, respectively. Overall survival was 65.1% ± 9.5% at 2 years, and 50.1% ± 10.5% at 3 years. Although survival rates were relatively worse in the subsets of patients aged < 63 years or with early metastasis (< 36 months after resection of primary site), these factors were not significantly correlated with overall survival (P = 0.13 and 0.19, respectively). All treatment-related complications were self-limited, without any grade 3-5 toxicity. Conclusions CIRT is one of the most effective nonsurgical treatments for colorectal lung metastases, which are relatively resistant to stereotactic body radiotherapy. CIRT is considered to be the least invasive approach even in patients who have undergone repeated prior thoracic metastasectomies. [ABSTRACT FROM AUTHOR]

The clinical results after carbon ion radiotherapy for the metastatic lung tumors believed to be in the state of oligo-recurrence were evaluated. One hundred and sixteen lesions in 91 patients with lung cancer metastasis were treated with carbon ion radiotherapy at our institute from April 1997 to February 2011. Regarding the prescribed dose, total dose ranged between 40 gray equivalents (GyE) and 80GyE, and fraction size ranged from 1 to 16 fractions. After a median followup period of 2.3 years (range, 0.3-13.1 years), the statistical overall survival rate and local control rate were 71.2% and 91.9% at 2 years after treatment, respectively. Treatmentrelated side effects were not a clinical problem.When classified by the primary organ, there were 49 cases of lung cancer, 20 cases of colorectal cancer, and 22 cases of others. The overall survival rate and local control rate for lung metastasis cases from lung cancer at 2 years after treatment were 81.5% and 92.4%, respectively, and 65.0% and 92.0% regarding lung metastasis from colorectal cancer. Carbon ion beam therapy for the metastatic lung tumors is a safe therapy, and the therapeutic effect is comparable to the outcome obtained from reported surgical resections. [ABSTRACT FROM AUTHOR]