Author of

• 10692

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  P1.08 - Poster Session 1 - Radiotherapy (ID 195)

  • Event: WCLC 2013
  • Type: Poster Session
  • Track: Radiation Oncology + Radiotherapy
  • Presentations: 1
  • Moderators:
  • Coordinates: 10/28/2013, 09:30 - 16:30, Exhibit Hall, Ground Level

  • 10701

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    P1.08-009 - Dynamic Tumor Tracking Radiotherapy with Real-Time Monitoring using Vero4DRT (ID 929)

    09:30 - 16:30  |  Author(s): K. Takayama
    • Abstract

    Background
    The Vero4DRT is a newly-developed innovative radiotherapy system with two special features. One is a pair of kV x-ray imagers which can monitor a 3-dimensional position of tumor in real time. The other is a gimbaled x-ray head which enables tumor tracking. This study is to evaluate the initial clinical experiences of dynamic tumor tracking irradiation with real-time monitoring for the lung using the Vero4DRT system.

    Methods
    Eligibility criteria for this study were (1) lung tumor with a diameter of 50 mm or less, (2) respiratory motion of 10 mm or more, (3) performance status of 0–2, and (4) written informed consent. Prior to treatment planning, spherical gold markers were placed around the tumor using a bronchoscope. Gross tumor volume (GTV) for tracking was delineated on a breath-hold CT at end-exhale. Margins for planning target volume (PTV) were determined for each patient considering errors due to the tracking irradiation. Prescription dose was 56 Gy in 4 fractions for T2a lung cancer and metastatic tumor, and 48 Gy in 4 fractions for the others. Dose-volume metrics were compared between the tumor tracking and conventional static irradiation using an in-house developed software. A 6-MV photon beam was delivered to the tumor with the gimbaled x-ray head toward predicted position based on the abdominal wall. During the irradiation, the tumor and the gold markers were monitored with kV imagers and EPID.

    Results
    The dynamic tumor tracking radiotherapy was successfully performed for 12 patients (10 males and 2 females). A median age was 83 years (range, 60-87 years). Histology was adenocarcinoma in 4 patients, squamous cell carcinoma in 3, non-small cell lung cancer in 1, metastatic tumor in 3, and unconfirmed in 2, respectively. Tumor diameter ranged from 12 to 36 mm (median, 21 mm). Median amplitude of respiratory motion was 16.8 mm (range, 11.3 to 33.5 mm). A mean PTV volume was 42.9 cc for the dynamic tracking, while that was 62.5 cc for the conventional irradiation. The tracking irradiation could reduce normal lung doses by 21.3% in mean. Dose covering 95% volume of GTV was not different between the two irradiation techniques with a mean difference of 0.66%. A mean treatment time per fraction was 37 minutes. The gold markers were well recognized with kV x-ray imagers through the whole treatment fractions. With a median follow-up period of 7.7 months (range, 2.1 – 19.2 months), local tumor was controlled in all patients. One patient experienced grade 2 radiation pneumonitis. No severe toxicity has been observed in any of the patients so far.

    Conclusion
    Dynamic tumor tracking irradiation with real-time monitoring using the Vero4DRT could reduce normal lung doses without any excess time. Preliminary outcomes were promising.

• 12544

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  P3.08 - Poster Session 3 - Radiotherapy (ID 199)

  • Event: WCLC 2013
  • Type: Poster Session
  • Track: Radiation Oncology + Radiotherapy
  • Presentations: 1
  • Moderators:
  • Coordinates: 10/30/2013, 09:30 - 16:30, Exhibit Hall, Ground Level

  • 12545

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    P3.08-001 - Feasibility of stereotactic body radiation therapy with concurrent chemotherapy for patients over 75 years old with Stage I non-small-cell lung cancer. (ID 241)

    09:30 - 16:30  |  Author(s): K. Takayama
    • Abstract

    Background
    Stereotactic body radiation therapy (SBRT) is now the standard treatment for elderly patients with inoperable Stage I non-small-cell lung cancer (NSCLC). However SBRT with concurrent chemotherapy may be feasible and effective to selected elderly patients with NSCLC. This retrospective study was aimed to evaluate the safety and tolerability of concurrent SBRT and chemotherapy in patients aged 75 years or older.

    Methods
    We reviewed the records of 11 NSCLC patients who were 75 years or older when treated with SBRT and concurrent chemotherapy with curative intent from 2009 to 2012. Five patients had T1 tumor, the others had T2 tumors. The median age was 81 years with a range of 76 to 88 years. Eight (72%) patients had chronic obstructive pulmonary disease. The median number of Eastern Cooperative Oncology Group (ECOG) performance status of the cases in the beginning of treatment was 1 with a range from 0 to 2. The median delivered radiation dose was 48 Gy in 4 fractions. Concurrent chemotherapy regimen was carboplatin plus paclitaxel, carboplatin plus docetaxel, paclitaxel alone, pemetrexed alone, and S1 alone.

    Results
    All patients received SBRT on schedule. Out of 11 patients, concurrent chemotherapy was successfully accomplished as originally planned in 8 (72%) patients. Initial effect of SBRT plus chemotherapy could be evaluated in all cases. Complete local remission was achieved in 10 patients. One patient alone had local recurrence. Distant metastases observed in 4 patients. In 2 patients, chemotherapy was intermitted due to grade 3 neutrophil count decreased and anemia (Common Terminology Criteria for Adverse Events version 4.0). In another, chemotherapy was broken off because of Grade 2 radiation pneumonitis. During the treatment, no other adverse event was shown. No treatment-related death was observed.

    	Grade 2	Grade 3
    Neutrophil count decreased	6 (55%)	1 (9%)
    Anemia	1 (9%)	2 (10%)
    Radiation pneumonitis	1 (9%)	0

    Conclusion
    SBRT plus concurrent chemotherapy might be feasible in selected patients aged 75 years or older with Stage I NSCLC.