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Volume 96 Number 2S Supplement 2016 incorporating mutational status (including EGFR and ALK) and systemic chemotherapy will be needed to further validate our findings. Author Disclosure: K. Yang: None. J.A. Miller: None. E.H. Balagamwala: None. L. Angelov: None. J.H. Suh: Consultant; Varian Medical Systems. Head of department; Cleveland Clinic. M.B. Tariq: None. A. Magnelli: None. S. Soeder: None. A.M. Mohammadi: None. T. Djemil: None. S.T. Chao: None.
3268 Avoiding Skin Creams Just Before Radiation: Good Advice or Much Ado About Nothing? B.C. Baumann,1 I.I. Verginadis,1 C. Zeng,1 C. Vachani,2 T.D. Solberg,3 C. Koumenis,1 and J.M. Metz1; 1University of Pennsylvania, Department of Radiation Oncology, Philadelphia, PA, 2University of Pennsylvania, Department of Radiation Oncology & OncoLink, Philadelphia, PA, 3 Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA Purpose/Objective(s): Radiation dermatitis is common & often treated with topical creams. Patients are traditionally advised to avoid lotions for several hours before radiation therapy (RT) based on concern that creams might increase skin dose. With modern RT’s improved skin sparing, this recommendation may be irrelevant. We hypothesize that applying either metallic or non-metallic creams before treatment would have minimal effect on skin dose. Materials/Methods: We conducted an online, 24-question anonymous survey of patients and providers to determine current skin cream practices. To evaluate the dosimetric effect of creams, we delivered 200 MU at 100 cm SSD & measured the dose at the surface and 2 cm depth in a tissue equivalent phantom with optically stimulated luminescent dosimeters (OSLDs), with and without two common skin creams, a topical emollient, & silver sulfadiazine. We assessed the effect of various photon & electron energies, cream thicknesses, & beam incidence on dose. The effect of creams on skin dose was also evaluated in C57BL/6 mice using g-H2AX IHC staining. Mice were shaved and irradiated to 2 or 4 Gy in a single fraction in the presence or absence of thin and thickly applied emollient. Each mouse served as its own control. Skin was harvested 1 hour after RT & stained for g-H2AX. Quantification of g-H2AX foci was performed using ImageJ. Results: 57 of 66 surveyed cancer patients (86%) & 44 of 47 providers (94%) either received or gave the advice to avoid applying creams prior to RT treatments. Measurements showed no difference in dose at the surface or 2 cm depth with or without a 1-2 mm application of either cream when using enface 6 or 15 MV photons. The same application of cream had no effect on surface dose as a function of beam incident angle from 15-60 , except for a 7% increase at 60 with the silver cream. Surface dose for 6 and 15 MV beams were significantly increased with a thicker (3 mm) layer of cream. For 6 MV, the surface dose was 105 cGy (emollient), 102 cGy (silver cream) & 88 cGy (controls). For 15 MV, the doses were 70, 60, & 52 cGy, respectively. With 6 & 9 MeV electrons, there was only a 2-5% increase in surface dose with use of creams. There were no dose differences at 2 cm depth. Irradiated skin in mice treated to 2 Gy and 4 Gy showed no significant difference in g-H2AX positive foci with or without creams (p>0.05). There was also no significant difference in g-H2AX positive foci based on differences in the applied cream thickness (p>0.05). Conclusion: This is the first dosimetric assessment of the effect of skin creams for radiation dermatitis. Our findings suggest that thin or moderately applied creams, even if applied just prior to RT, have minimal impact on skin dose, regardless of beam energy or beam incidence. Applying very thick amounts of cream just prior to RT increased surface dose and should be avoided. Pre-clinical results confirm that skin creams have minimal effect on the surface dose. Use of creams prior to radiation can be liberalized, which may improve patient quality-of-life. Author Disclosure: B.C. Baumann: None. I.I. Verginadis: None. C. Zeng: None. C. Vachani: None. T.D. Solberg: None. C. Koumenis: None. J.M. Metz: None.
3269 Palliative Whole-Lung Irradiation as a Treatment Option in Patients With Pulmonary Dissemination Not Eligible for Systemic Treatment A. Napieralska,1 S.C. Blamek,2 and L. Miszczyk3; 1MSC Memorial Cancer Center and Institute of Oncology, Gliwice Branch, Gliwice, Poland, 2Department of Radiotherapy, Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, Gliwice Branch, Gliwice, Poland, 3MSC, Gliwice, Poland Purpose/Objective(s): Evaluation of safety and effectiveness of whole lung irradiation (WLI) as a palliative treatment for multiple pulmonary metastases. Materials/Methods: Retrospective analysis of 108 patients (106 adults, 2 children) who received whole lung irradiation between 2002 and 2015. The median age at the time of irradiation was 59 (range: 5-82), 56% were men. Primary diagnosis was sarcoma in 23 patients (21%), renal cell carcinoma (RCC) in 24 (22%), gastrointestinal cancer in 30 (28%) and other cancers in 31 (29%). The time from the diagnosis of lung metastases to WLI ranged from 0 to 54 months (median 7). In majority of them it was the only available treatment (due to the lack of systemic treatment possibility/ contraindications/ and progression during systemic therapy). Most of the patients were in good performance status (PS) e 6% ECOG 0, 75% ECOG 1, 19% ECOG 2. 94% had more than 5 lung metastases, 77 (71%) had metastases also in other organs. The primary tumor was controlled in 44%. 11 had surgery, 65 chemotherapy/hormonotherapy, and 14 radiotherapy due to lung metastases before WLI. 105 received WLI with fraction dose (fd) of 1.1Gy and total dose (TD) of 11Gy, 3 with fd of 1.5Gy (TD 15 Gy). In most of them a 3D plan (72%) with 2 opposite fields (91%) was made. Kaplan-Meier method and log rank test were used. Overall survival (OS) and local control (LC) were calculated from the end of WLI. Results: All patients completed the treatment in 10 consecutive working days. 85 (79%) had control visit after the treatment. LC was evaluated in 49 cases, 31 responded to treatment. Local progression of was observed in 28/48. Progression in other sites occurred after WLI in 34 of 60 evaluated patients. 40 patients (37%) declared improvement in general status or reduction of symptoms. In 20% of patients new symptoms occurred after WLI (dyspnea in 6 patients, fatigue in 9, weight loss in 3, cough in 6, pain in 1). In 6 patients deterioration of PS and in 3 improvement was observed. Median OS after treatment was 5.4 months (range: 0.2-112 months). One-, 2-, and 5-year OS was 22%, 12% and 3% respectively. The best OS was observed in sarcoma group (35%, 15%, and 5%, respectively). Only two factors affected OS: performance status (PZ0.002) and response to WLI (PZ0.009). Sarcoma patients with better PS had better OS (PZ0.01). One-,2-, and 5-year OS in younger than 60 years sarcoma patients was 50%, 21% and 8% compared to 0% in the older (PZ0.01). Older patients with gastrointestinal cancers had better OS compared to younger ones (PZ0.03; 1- and 2-year OS of 27% and 7% vs. 0%). Conclusion: WLI can be considered in selected patients with pulmonary dissemination of sarcoma or RCC ineligible to other forms of treatment. The value of WLI in other cancers requires further investigation. Author Disclosure: A. Napieralska: None. S.C. Blamek: None. L. Miszczyk: None.
3270 Spine Stereotactic Ablative Body Radiation Therapy (SABR) With Volumetric Modulated Arc Therapy (VMAT) for Vertebral Metastases With and Without Metastatic Spinal Cord Compression (MSCC) M.M. Gestaut,1 N. Thawani,2 S. Kim,3 V.R. Gutti,3 A. Morrow,3 R.A. Ward,4 J.H. Huang,5 and M.K. Patel1; 1Baylor Scott & White Texas A&M Radiation Oncology, Temple, TX, 2University of Arizona Cancer Center Dignity Health Saint Joseph Hospital Radiation Oncology, Phoenix, AZ, 3Baylor Scott and White Physics Division, Temple, TX, 4 Baylor Scott and White Orthopedic Surgery, Temple, TX, 5Baylor Scott and White Neurosurgery, Temple, TX