2331 - Outcomes of Patients with Intracranial Germinoma Enrolled on the Pediatric Proton Photon Consortium Registry
Presenter(s)
E. Cha1, S. A. Mihalcik2, D. J. Indelicato3, N. N. Laack II4, R. P. Ermoian5, V. S. Mangona6, S. M. Perkins7, S. L. Wolden8, J. Y. Lee9, J. P. Perentesis10, J. D. Palmer11, D. S. C. Tsang12, C. E. Hill-Kayser13, Y. Kwok14, I. MacEwan15, B. R. Eaton16, H. V. Le17, A. C. Paulino1, and T. I. Yock18; 1Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 2Northwestern Medicine Chicago Proton Center, Warrenville, IL, 3Department of Radiation Oncology, University of Florida, Jacksonville, FL, 4Department of Radiation Oncology, Mayo Clinic, Rochester, MN, 5Department of Radiation Oncology, University of Washington, Seattle, WA, 6Texas Center for Proton Therapy, Irving, TX, 7Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO, 8Memorial Sloan Kettering Cancer Center, New York, NY, 9Procure Proton Therapy Center, Somerset, NJ, 10Department of Oncology, Cancer & Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 11Department of Radiation Oncology, The Ohio State University Wexner Medical Center, Columbus, OH, 12Radiation Medicine Program, Princess Margaret Cancer Centre and Toronto Western Hospital, University Health Network, Toronto, ON, Canada, 13Department of Radiation Oncology, Hospital of the University of Pennsylvania, Philadelphia, PA, 14Department of Radiation Oncology, University of Maryland Proton Treatment Center, Baltimore, MD, 15California Protons Cancer Therapy Center, San Diego, CA, 16Department of Radiation Oncology, Winship Cancer Institute of Emory University, Atlanta, GA, 17Department of Radiation Oncology, Royal Adelaide Hospital, Adelaide, SA, Australia, 18Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA
Purpose/Objective(s):
Intracranial germinomas (IGs) are rare, with outcomes comparing modern treatment paradigms not well characterized. We describe outcomes in patients (pts) with IGs treated with radiation (RT), with or without chemotherapy (CT).Materials/Methods:
Pts with IGs treated from 2010-2024 were retrospectively reviewed on an IRB-approved protocol via the multi-center Pediatric Proton/Photon Consortium Registry. Clinical and treatment data were collected. Kaplan-Meier and Cox regression models were used to estimate overall and recurrence-free survival (OS, RFS).Results:
Of 127 pts, 75% were male (n=95) with median age at diagnosis of 13 (IQR 11-17). Most were from the United States (91%, n=115). Tumors were primarily supratentorial (98%, n=123), and 95 cases (75%) were non-metastatic including 15 bifocal cases. For the 31 with metastatic (M+) disease, 3 were M1, 24 M2, and 3 M3. Most (91%, n=116) received neoadjuvant (NA) CT. Among these pts, 70% (n=89) were enrolled or treated as per clinical trials, with 89% (n=79) as per ACNS 1123. Most received carboplatin/etoposide. All received RT: 24% (n=30) with craniospinal irradiation (CSI), 63% (n=80) whole ventricular RT (WVRT), 4% (n=5) whole brain RT (WBRT), and 9% (n=12) involved field RT (IFRT) alone. Median dose was 36 Gy (IQR 30-36). Almost all (94%, n=119) were treated with proton therapy, of which almost half (45%, n=57) was passive scatter proton therapy (PSPT) and 45% intensity-modulated proton therapy (IMPT). The rest were treated with a mix of proton/photon modalities. Median follow-up was 37 months (IQR 22-57.5). The 3- and 5-year OS and RFS were 99% and 96%, and 99% and 91%. Six (5%) developed recurrences at a median of 37 months post-RT (IQR 12.75-47.75; see Table for recurrence details). Isolated distant recurrence was not seen. For the 31 M+ pts, 14 were treated with CSI, 1 WBRT, 14 WVRT and 2 IFRT alone. Two of the 31 M+ pts relapsed, and both were treated with CT followed by RT. One pt died of leukemia 8 months post-chemoRT.Conclusion:
This patterns of treatment study showed that IG is treated most commonly with NACT followed by RT, with excellent locoregional control and survival. The lack of distant relapse validates the current approach of using WVRT followed by a primary site boost for M0 disease. More than 85% of M+ pts treated with less than CSI were relapse-free, raising the question as to whether all M+ pts need CSI. Abstract 2331 - Table 1| Pts | M Status (location) | Therapy | CT Response* | RT Details | Time to Relapse (months) | Relapse Pattern** |
| 1 | M2 (pineal, third ventricle) | CT, RT | PR | WVRT 21 Gy + 18.6 Gy boost | 6 | R |
| 2 | M0 (suprasellar) | RT | U | WVRT 25.5 Gy + 24 Gy boost | 44 | L, D |
| 3 | M0 (suprasellar) | CT, RT | CR | WVRT 18 Gy + 12 Gy boost | 97 | L, R, D |
| 4 | M0 (bifocal) | CT, RT | CR | WVRT 24 Gy + 15 Gy boost | 7 | L |
| 5 | M0 (pineal) | CT, RT | U | WVRT 24 Gy + 15 Gy boost | 49 | R |
| 6 | M3 (pineal, third ventricle, spinal) | CT, RT | CR | IFRT 30 Gy | 30 | L, R, D |
| *PR: partial response; CR: complete response; U: unavailable **L: local; R: regional; D: distant | ||||||