Efficacy of the smaller target volume for stage III non-small cell lung cancer treated with intensity-modulated radiotherapy

Abstract

Abstract. The present study reports the local recurrence, distant metastasis, progression-free survival, overall survival and radiation toxicity between two arms of stage III non-small cell lung cancer (NSCLC) treated with intensity-modulated radiotherapy (IMRT); one arm with clinical target volume (CTV) and the other without CTV. The two arms of local recurrence, distant metastasis, progression-free survival, overall survival, grade 3-4 radiation esophagitis and hematological toxicity had no statistical significance. However, the grade 3-4 radiation pneumonia rate of the group without CTV was significantly decreased. This supports the concept that stage III NSCLC treated with IMRT, which omitted CTV, can reduce the occurrence of radiation pneumonia. The aim of the present study was to analyze the feasibility of the smaller target volume for stage III NSCLC treated with IMRT. Data from 105 patients with stage III NSCLC who were hospitalized and received IMRT between January 1, 2008 and November 30, 2012 were retrospectively analyzed. A total of 55 cases were irradiated with target volume without CTV and 50 cases were irradiated with CTV. Dose prescription was 100% PTV at 54-63 Gy/27-35 F/5.4-7 weeks. The two arms of the patient characteristics and treatment deliveries had no statistical significance. The two arms of the patients were compared for local recurrence, distant metastasis, progression-free survival, overall survival and radiation-related toxicity. In the arms without and with CTV, the local relapse and distant metastases rates were 32.7 and 32.0% (P=1.000) and 56.4 and 48.0% (P=0.946), respectively. The median progression-free survival time for the two arms was 9 months (P=0.619). The 1-, 2-and 3-year survival rates of the arms without and with CTV were 74.5, 43.6 and 23.6%, and 70.0, 46.0 and 20.0% (P=0.956), respectively. In the two arms, grade 3-4 radiation esophagitis and hematological toxicity had no statistical significance. However, in the arm without CTV, grade 3-4 radiation pneumonia was only 5.5%, compared with 18.0% in the arm with CTV (P=0.044). In conclusion, the smaller target volume for stage III NSCLC treated with IMRT was feasible.

Is clinical target volume necessary?—a failure pattern analysis in patients with locally advanced non-small cell lung cancer treated with concurrent chemoradiotherapy using intensity-modulated radiotherapy technique

“…The second reason can be deduced from the present status of treatment failure patterns for LA-NSCLC treated with concurrent chemoradiotherapy. Consistent with many previous studies (22)(23)(24), we found that major failure occurred in the distant areas, which may shadow over the local-regional recurrences; most local-regional recurrences occurred with IN-PTV-g rather than subclinical regions, implying that the current standard radiation dose for LA-NSCLC (60 Gy per 30 fractions) may be insufficient in eliminating gross tumors. Thus, in such a state, using radical radiation doses to treat the invisible subclinical lesions even when the visible gross tumors cannot be well controlled is excessive.…”

Is a clinical target volume (CTV) necessary for locally advanced non-small cell lung cancer treated with intensity-modulated radiotherapy? —a dosimetric evaluation of three different treatment plans

“…Decades of experience led to the conclusion that 45-50 Gy results in high control rates for subclinical disease in patients with epithelial tumors (3)(4)(5)(6). However, recent studies have shown that omission of the CTV in lung cancer radiotherapy does not compromise local tumor control (7,8). This latter result may reflect sufficient dose coverage to the subclinical disease extent within certain margins by delivering volumes in which at least 60 Gy were administered for gross tumor eradication.…”

Association of Target Volume Margins With Locoregional Control and Acute Toxicities for Non-small cell lung cancer Treated With Concurrent Chemoradiation Therapy

“…In their retrospective series of 105 patients, Liang et al . found that omission of a 6–8mm CTV margin resulted in smaller PTVs, similar rates of local recurrence, and decreased grade 3–4 radiation pneumonitis (7). Because 4DCT simulation was not used, ITV margins ranged from 3–15mm.…”

“…Few studies evaluated the effect of target volume margins on clinical outcomes for inoperable NSCLC (7–9). We hypothesized that smaller margins would not compromise locoregional control and would associate with fewer acute toxicities in the setting of concurrent CRT with PET/CT-based treatment planning, 4DCT simulation, and daily CBCT.…”