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J. Newton
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P3.14 - Radiotherapy (ID 730)
- Event: WCLC 2017
- Type: Poster Session with Presenters Present
- Track: Radiotherapy
- Presentations: 1
- Moderators:
- Coordinates: 10/18/2017, 09:30 - 16:00, Exhibit Hall (Hall B + C)
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P3.14-008 - Clinical Characteristics Matrix of Lung Tumor Under Stereotactic Ablative Body Radiotherapy (SABR) (ID 9980)
09:30 - 09:30 | Author(s): J. Newton
- Abstract
Background:
Early Stage lung cancer can be treated with surgical resection and SABR. In clinical practice, it may be important to find a characteristic matrix for precision radiotherapy. The characteristic matrix for a lung tumor should include: 1) a time factor that incorporates the motion pattern of the tumor, 2) spatial factor which is related to volumetric information including location and surrounding environment, and 3) intrinsic characteristics which are related to the biologic information and could be represented by imaging characteristics. In this investigation, the typical heterogeneous characteristics matrix of lung tumors treated with SABR were studied.
Method:
A total of 38 patients with 41 lung tumors were retrospectively reviewed. All targets were treated with SABR. 4-Dimensional Computed Tomography (4DCT) was used for simulation. The time factor parameter was defined by the breathing cycle signal recorded by an infrared reflector. The internal target volumes (ITV) were generated by the cine image set through phase binning method. The intrinsic characteristics of tumors were described by the image information inside the tumor, which was represented by the ITV. This target image information was described by the minimum Hounsfield Unit (HU), maximum HU, mean HU, and standard deviation.
Result:
For spatial location, there were 23 tumors in the right lung and 18 tumors in the left lung. For phase surrogate signal, the mean amplitude was 0.7 cm with standard deviation (SD) = 0.3 cm. Mean breathing cycle was 3.5 seconds (SD = 1.1). Mean prescription isodose volume (PIV) was 38.3 cc (SD = 37.7) and the mean corresponding diameter was 3.8cm (SD = 1.1cm). Mean ITV volume was 13.4 cc (SD = 20.4) and the corresponding diameter was 2.4 cm (SD = 1.2). With regard to imaging information, ITV minimum HU was -883.1 (SD = 120.3); ITV maximum HU was 222.3 (SD = 487.9); ITV mean HU was -224.9 (SD = 188.2). PTV minimum HU was -937.1 (SD = 62.2); PTV maximum HU was 437.1 (SD = 506.1); PTV mean HU was -482.3 (SD = 192.6).
Conclusion:
A characteristics matrix was computed for SABR treated lung tumors based on time, imaging, and spatial information. The matrix could be further expanded and assessed for intra-fractional and post treatment analysis. Other imaging modalities such as MRI and incorporation of immune system stimulation mechanisms can be combined with big data analysis methodologies for patient treatment options in precision medicine through similarity matching.
