Practical Radiation Oncology: April-June Supplement 2013 radial expansion for the CTV. A 0.5cm expansion on the CTV created the PTV. The fused scans and structures were then exported into Pinnacle. Based on published dosimetric series using the set angles of 80, 110, 160, 210 and 240, we ran 6 MV IMRT plans with at least 94% PTV coverage to a dose of 5040cGy in 28 fractions on each data set using the position of the tumor in maximum inhale vs. exhale. The plans were then compared in terms of mean lung dose, total lung V5 and V20, heart mean dose and V30, and liver mean dose. Results: Results showed that in three of the four plans, the GTV defined with the auto-contouring SUV 2.5 parameter was smaller on the exhale plan by 9%, 15% and 30%.Yet in all three of these cases, there was not uniform superiority of the exhale phase in all of the parameters studied. The total lung V5 was better on the exhale plans in the majority (3/4) of the cases. There was one patient with the best parameters on the inhale phase. The heart V30 showed a less than 5% difference between inhale and exhale in all cases. The heart mean dose, however, showed more variation with two cases exhibiting lower DVHs by 6.5-8.6% in the exhale phase. The liver mean was lowest in inhale phase for all cases. Conclusion: This study suggests there may be variation in delineation of maximum inhalation vs. exhalation 4D PET/CT esophageal cancer volumes which may be exploited to maximize lung and cardiac sparing. Our data suggests that personalizing the patient's treatment parameters by evaluating maximum inhalation vs. exhalation dosimetry is worthy of further study. Author Disclosure Block: N. Figura: None. K. Latifi: None. T.J. Dilling: None. C.C. Kuykendall: None. E.A. Eikman: None. E.G. Moros: None. G.G. Zhang: None. S. Leuthold: None. C. Mehra: None. S.E. Hoffe: None.
193 Diffusion-Weighted Whole-Body Imaging With Background Body Signal Suppression (DWIBS) – Application in Planning for Cyberknife Therapy in Patients With Gliomas R. Balaji, R. Devi, J. Stumpf, Apollo Cancer Hospitals, CHENNAI, India Purpose/Objectives: To describe the use of DWIBS Diffusion-weighted whole-body imaging with background body signal suppression for CyberKnife therapy in patients with gliomas. Materials/Methods: Eighteen patients with the gliomas underwent planning MRI with DWIBS imaging of the brain in addition to high resolution T1 contrast imaging. Results: DWIBS produces PET like images and helps in better tumor delineation and increase confidence levels to outline tumor margins especially in infiltrative gliomas.
Poster Presentations
S35
Conclusions: DWIBS can be adapted for planning protocols for CyberKnife therapy in patients with gliomas as an adjunct to routine high resolution T1 contrast imaging. Author Disclosure Block: R. Balaji: None. R. Devi: None. J. Stumpf: None.
194 Reflectance Confocal Microscopy in Patients Undergoing Radiation Therapy C.A. Barker, Memorial Sloan-Kettering Cancer Center, New York, NY Purpose/Objectives: Radiation therapy (RT) is frequently used in the management of cutaneous malignancies. Targeting of skin cancers with RT is often achieved by direct inspection. However, some parts of the tumor may be occult on physical examination. Moreover, some cutaneous malignancies are not easily discernible on direct inspection. Cancer imaging modalities frequently used in conjunction with RT (computed tomography, magnetic resonance imaging, positron emission tomography) do not image the skin adequately. In recent years, RCM has emerged as a novel skin imaging modality that allows clinicians to assess morphology of the skin, and identify pathologic conditions like cancer. The objective of this study was to search and analyze the literature reporting the use of RCM in patients undergoing RT. Materials/Methods: The Web of Science online academic citation index was searched for the terms “reflectance confocal microscopy" and “radiation therapy" or “radiotherapy". Reference textbooks on the subject of reflectance confocal microscopy (Reflectance Conforcal Microscopy of Cutaneous Tumors and Reflectance Confocal Microscopy for Skin Diseases) were also searched. Results of the literature search were analyzed. Results: Eight-hundred and eleven studies on RCM were identified. Many dealt with applications of RCM in the treatment of skin disease. Two reports of using RCM after breast RT in six patients have been reported. In one case report, the technique was used after treatment to detect cutaneous recurrence in the skin after breast RT. In a case series reporting on five patients, RCM was used to characterize the dermatologic response of the normal skin to RT (radiation dermatitis). No studies reported the use of reflectance confocal microscopy for targeting purposes, or treatment response of primary skin cancers. Conclusions: RCM is a potentially useful tool in the evaluation of the skin cancer patients undergoing dermatologic RT. Further study is necessary to determine the value of RCM in skin cancer RT targeting and treatment response. Author Disclosure Block: C.A. Barker: None.
193 Diffusion-Weighted Whole-Body Imaging With Background Body Signal Suppression (DWIBS) – Application in Planning for Cyberknife Therapy in Patients With Gliomas R. Balaji, R. Devi, J. Stumpf, Apollo Cancer Hospitals, CHENNAI, India Purpose/Objectives: To describe the use of DWIBS Diffusion-weighted whole-body imaging with background body signal suppression for CyberKnife therapy in patients with gliomas. Materials/Methods: Eighteen patients with the gliomas underwent planning MRI with DWIBS imaging of the brain in addition to high resolution T1 contrast imaging. Results: DWIBS produces PET like images and helps in better tumor delineation and increase confidence levels to outline tumor margins especially in infiltrative gliomas.
Poster Presentations
S35
Conclusions: DWIBS can be adapted for planning protocols for CyberKnife therapy in patients with gliomas as an adjunct to routine high resolution T1 contrast imaging. Author Disclosure Block: R. Balaji: None. R. Devi: None. J. Stumpf: None.
194 Reflectance Confocal Microscopy in Patients Undergoing Radiation Therapy C.A. Barker, Memorial Sloan-Kettering Cancer Center, New York, NY Purpose/Objectives: Radiation therapy (RT) is frequently used in the management of cutaneous malignancies. Targeting of skin cancers with RT is often achieved by direct inspection. However, some parts of the tumor may be occult on physical examination. Moreover, some cutaneous malignancies are not easily discernible on direct inspection. Cancer imaging modalities frequently used in conjunction with RT (computed tomography, magnetic resonance imaging, positron emission tomography) do not image the skin adequately. In recent years, RCM has emerged as a novel skin imaging modality that allows clinicians to assess morphology of the skin, and identify pathologic conditions like cancer. The objective of this study was to search and analyze the literature reporting the use of RCM in patients undergoing RT. Materials/Methods: The Web of Science online academic citation index was searched for the terms “reflectance confocal microscopy" and “radiation therapy" or “radiotherapy". Reference textbooks on the subject of reflectance confocal microscopy (Reflectance Conforcal Microscopy of Cutaneous Tumors and Reflectance Confocal Microscopy for Skin Diseases) were also searched. Results of the literature search were analyzed. Results: Eight-hundred and eleven studies on RCM were identified. Many dealt with applications of RCM in the treatment of skin disease. Two reports of using RCM after breast RT in six patients have been reported. In one case report, the technique was used after treatment to detect cutaneous recurrence in the skin after breast RT. In a case series reporting on five patients, RCM was used to characterize the dermatologic response of the normal skin to RT (radiation dermatitis). No studies reported the use of reflectance confocal microscopy for targeting purposes, or treatment response of primary skin cancers. Conclusions: RCM is a potentially useful tool in the evaluation of the skin cancer patients undergoing dermatologic RT. Further study is necessary to determine the value of RCM in skin cancer RT targeting and treatment response. Author Disclosure Block: C.A. Barker: None.
