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Y. Iizuka
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P1.14 - Radiotherapy (ID 700)
- Event: WCLC 2017
- Type: Poster Session with Presenters Present
- Track: Radiotherapy
- Presentations: 1
- Moderators:
- Coordinates: 10/16/2017, 09:30 - 16:00, Exhibit Hall (Hall B + C)
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P1.14-015 - Local Recurrence Rate and Timing after Stereotactic Body Radiotherapy for Lung Cancer: Need for Long-term Follow-up (ID 8377)
09:30 - 09:30 | Author(s): Y. Iizuka
- Abstract
Background:
Local control rate by stereotactic body radiotherapy (SBRT) for stage I non-small cell lung cancer (NSCLC) has been reported to be approximately 90%. But, most studies had relatively short follow-up time, and our group has previously published preliminary report that late local recurrence (LR) might not be negligible. Thus, the aim of this study was to assess LR rate and timing after SBRT, using long-term follow-up data of large cohorts from single institution.
Method:
Eligible patients were those who were treated with SBRT (isocenter prescription of 48Gy/4fr) between April 1998 and August 2014 for primary/recurrent NSCLC < 5cm and with > 6 months follow-up time.
Result:
Figure 1A total of 213 patients (229 tumors) were analyzed. Tumor and treatment characteristics are shown in Table. Median follow-up time was 7 years [95% confidence interval (CI) 6.2–7.8]. 5-year overall survival and progression-free survival rate was 47%[95% CI 40–54] and 32%[95% CI 26–39], respectively. The number of LR was 45, and 5- and 10-year cumulative incidence of LR was 18%[95% CI 13–23] and 26%[95% CI 18–33], respectively. Clinical T stage, histology, tumor location, overall treatment time and use of cone-beam CT for patient set-up did not impact LR rate, as shown in Table. Median time to LR was 1.7 years (range: 0.6–9.5, interquartile range: 1.0–3.2) and time to LR was significantly longer in adenocarcinoma (Adeno) than in squamous cell carcinoma (SqCC) (median: 2.7 vs. 1.1 years, p=0.04). The number of late LR > 5 years after SBRT was six. The histology of tumors with late LR was Adeno/SqCC/unknown=3/1/2 (one of two unknown cases was proven to be Adeno by salvage surgery). Five of six late LRs were isolated LR as the first progression site.
Conclusion:
Late LR was not uncommon. Long-term follow-up after SBRT is needed, especially for adenocarcinoma.
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P2.05 - Early Stage NSCLC (ID 706)
- Event: WCLC 2017
- Type: Poster Session with Presenters Present
- Track: Early Stage NSCLC
- Presentations: 1
- Moderators:
- Coordinates: 10/17/2017, 09:30 - 16:00, Exhibit Hall (Hall B + C)
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P2.05-002 - A Pilot Study on the Safety and the Efficacy of Dose Escalation in Stereotactic Body Radiotherapy for Peripheral Lung Tumor (ID 8164)
09:30 - 09:30 | Author(s): Y. Iizuka
- Abstract
Background:
Stereotactic body radiation therapy (SBRT) is an important treatment option of solitary lung tumor. A total dose of 48Gy in 4 fractions (fr.) at the isocenter has been most widely used in Japan, however, local recurrences were observed in the long term follow-up study in 10% or more. To improve local control rates after SBRT, the most promising treatment strategy will be dose escalation. Then we started a pilot study to evaluate the safety and efficacy of dose escalation in SBRT for peripheral lung tumor.
Method:
We designed to enroll 35 patients treated with SBRT prospectively. The primary endpoint was the incidence of adverse effects within 1 year after SBRT. Adverse effects were evaluated by the CTCAE ver. 4.0. In this study, the prescription dose was 70 Gy in 4 fr. at the isocenter, covering the planning target volume (PTV) surface with 70%-isodose line.
Result:
A total of 35 patients were enrolled between October 2014 and January 2016. Patient and tumor characteristics are shown in the table. The median follow-up duration was 21.0 months (range, 4.2–31.2 months). Grade 2 radiation pneumonitis and Grade 2 rib fractures were observed in 5 patients (14.3%) and 5 (14.3%), respectively. There was no other Grade 3 or more adverse effect. Local recurrence was observed in one patient, and it was a recurrence of metastatic lung tumor. Out of 32 primary lung cancers, no local recurrence was observed.Patient and tumor characteristics
Characteristics Number % Patients 35 100 Age (y) Median (range) 77 (58-92) Gender Male 23 66 Female 12 34 ECOG performance status 0 10 28 1 22 63 2 3 9 Disease Primary lung cancer 32 91 Histology Adenocarcinoma 10 28 Squamous cell carcinoma 3 9 Clinically diagnosed 19 54 T-stage T1a 15 43 T1b 11 31 T2a 6 17 Lung metastasis 3 9 Target location Upper/middle 26 74 Lower 9 26
Conclusion:
We confirmed that the treatment method is feasible in the acute and subacute phases. It was also suggested that this method can obtain excellent local control rate.
