S602
International Journal of Radiation Oncology Biology Physics
3044
to determine if children treated with chemoradiation experience the same frequency, severity, and duration of treatment-related lymphopenia as adults. Materials/Methods: Medical records of children with brain tumors or sarcomas who underwent concurrent chemoradiation therapy at Johns Hopkins Hospital from 1997-2011 were reviewed with IRB approval. Those eligible for inclusion in this study had at least one complete blood count recorded before therapy, as well as monthly or bi-monthly counts drawn for the subsequent 12 months. Chi-square test was used to compare the number of children with grade III-IV lymphopenia (absolute lymphocyte count < 500 cells/mm3) before and after therapy. Mean lymphocyte counts at different time points were compared using Student’s t-test. Results: A total of 53 patients, 28 with CNS tumors and 25 with sarcomas, were studied. Their median age was 11 years (range, 2-20). Pre-treatment lymphocyte counts in these patients were 500 cells/mm3 or greater in all patients, with a median of 2175 (range, 700-4502) in CNS tumors and 2430 (1200-5490) in sarcomas. Two months after initiation of chemoradiation, 66% experienced grade III-IV lymphopenia (median 300 [452450, p < 0.0001] for CNS tumors, and 480 [5-890, p < 0.0001] for sarcomas). Lymphocyte counts remained significantly lower than baseline 12 months later, with median lymphocyte counts 415 (50-1180, p < 0.02) and 1145 (240-2239, p < 0.05) respectively. Patients with medulloblastoma who had received craniospinal radiation were significantly more lymphopenic at two months than those with other brain tumors (93% vs 39%, p Z 0.0019). The limited number of patients, heterogeneous patient population, and differing treatment regimens in this study render a meaningful correlation of the lymphopenia and treatment outcome impossible in this initial analysis. Conclusions: Sixty-six percent of children with brain tumors or sarcomas developed grade III-IV treatment related lymphopenia two months after starting chemoradiation. This profound lymphopenia persisted during the one year of follow-up. Despite the presence of a functional thymus gland, the frequency, severity, and duration of treatment-related lymphopenia in children is very similar to that seen in adults. Further studies are needed to determine if this is associated with poorer survival as is seen in adults. These finding suggest that research focusing on means to preserve the immune system during chemoradiation may be of major importance in pediatric oncology. Author Disclosure: M. Miljkovic: None. S.A. Grossman: None. X. Ye: None. S. Batko-Yovino: None. S. Terezakis: None.
Pediatric Head and Neck Carcinoma: Patient Demographics and Treatment Outcomes e A SEER Database Study O.H. Gayar,1 M.A. Elshaikh,1 T. Ghanem,1 M.L. Cote,2 J. Ruterbusch,2 A.D. Paulino,3 and F. Siddiqui1; 1Henry Ford Health Systems, Detroit, MI, 2 Wayne State University Karmanos Cancer Institute, Detroit, MI, 3The Methodist Hospital, Houston, TX Purpose/Objective(s): Though head and neck (H&N) squamous cell carcinomas (SCCs) are common in adults, they are very rare in the pediatric population. The purpose of this study is to examine patient and treatment factors in pediatric patients treated for non-nasopharyngeal SCC of the H&N in the SEER database. Materials/Methods: The SEER database was queried for the years 19732009 for H&N SCC cases in children aged 0-19. The cohort was defined using AYA site recodes 8.2.2 (lip, oral cavity, pharynx), 8.2.3 (nasal cavity, middle ear, sinus, larynx, ill defined H&N), and histology codes 8010, 8020, 8070-8071, 8082-9083. Results: Ninety-one pediatric patients were diagnosed with various H&N malignancies. 56 (62%) were male and 35 (38%) were female. 71 were white, 10 were black and 10 patients were of other races. Two (2%) patients were age 0-4 years, 7 (8%) were age 5-9, 20 (22%) were age 1014, and 62 (68%) were age 15-19. Histologically, 20 (22%), 31 (34%), 12 (13%), and 12 (13%) patients had well differentiated, moderately differentiated, poorly differentiated, and undifferentiated SCC respectively. Forty patients (44%) had local stage SCC and 38 (42%) had regional or distant SCC at diagnosis. Primary tumor sites were larynx in 12 (13%), lip in 7 (8%), oral cavity in 43 (47%), oropharynx in 6 (7%), salivary gland in 10 (11%), and 12 (13%) had SCC of other H&N sites. Regarding treatment, 33 patients (36%) had surgery alone, 14 (15%) had radiation (RT) alone and 34 (37%) had combined RT and surgery. Of the patients who received RT, 45 had external RT, 2 had implants, and 1 had both. RT was more often utilized in older pediatric patients for treatment. The 5-year survival rate (OS5) was 68% for all patients: 68.3% and 87.5% for white and black patients respectively. OS5 was 72.7% for males and 57.1% for females. It was 82.5%, 100%, 61.3%, 50%, and 72% for larynx, lip, oral cavity, oropharynx, and salivary gland sites correspondingly. For well, moderately, poorly, and undifferentiated malignancies the OS5 was 77.3%, 72.8%, 38.2%, and 66.7% respectively. For patients treated with surgery alone OS5 was 96.4%. It was 54.5% for patients treated with RT alone and 53.3% for those treated with combined RT and surgery. Conclusions: Though pediatric H&N SCC is a rare entity, it is a case unlike its adult counterpart that needs to be studied further. Our study showed that these tumors occurred most commonly in the oral cavity and in adolescents. It is also noted that RT was used more in older pediatric patients for treatment. Also, results compared more favorably in pediatric larynx and oral cavity primaries than in adults. Finally, those treated with surgery alone had the highest survival rates likely related to the fact that those getting surgery alone had early stage cancers. Differences in etiology and treatment capabilities must be taken into further consideration. Author Disclosure: O.H. Gayar: None. M.A. Elshaikh: None. T. Ghanem: None. M.L. Cote: None. J. Ruterbusch: None. A.D. Paulino: None. F. Siddiqui: None.
3045 The Frequency, Severity, and Duration of Treatment-Related Lymphopenia in Children With Cancer M. Miljkovic,1 S.A. Grossman,2 X. Ye,2 S. Batko-Yovino,2 and S. Terezakis2; 1Sinai Hospital, Baltimore, MD, 2The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, MD Purpose/Objective(s): Adults with brain, pancreatic, lung, and head and neck cancers commonly develop severe and long-lasting lymphopenia two months following chemoradiation, which has recently been found to be an independent predictor of survival. This retrospective study was conducted
3046 Clinical Practice Patterns of Pediatric Image Guided Radiation Treatment: Results From an International Pediatric Research Consortium S.A. Terezakis,1 S. MacDonald,2 K. Dieckmann,3 K. Nilsson,4 R. Villar,5 A. Nechesnyuk,6 B. Winey,2 E. Ford,7 C. Malet,8 and E. Tryggestad9; 1 Johns Hopkins School of Medicine, Baltimore, MD, 2Massachusetts General Hospital, Boston, MA, 3Universita¨t Klinik Fu¨r Strahlentherapie und Strahlenbiologie, Vienna, Austria, 4Akademiska Sjukhuset, Uppsala, Sweden, 5Boldrini Hospital, Sao Paolo, Brazil, 6Federal Scientific Clinical Center of Children’s Hematology, Oncology and Immunology, Moscow, Russian Federation, 7University of Washington, Seattle, WA, 8Centre de Lutte Contre le Cancer Le´on Be´rard, Lyon, France, 9Mayo Clinic, Rochester, MN Purpose/Objective(s): Image-guided radiation treatment (IGRT) has become standard practice for multiple tumor types in the adult population. IGRT has not been well-studied in the pediatric population and concern for additional radiation dose as a result of on-treatment imaging has made its use controversial in children. We evaluated clinical patterns of pediatric IGRT practice through an international Elekta pediatrics consortium. Materials/Methods: A formal survey of 53 questions was distributed to five international institutions with dedicated pediatric expertise evaluating