Germ Cell Tumors

Classic Triad for Suprasellar Germ Cell tumors

  • diabetes insipidus
  • precocious or delayed sexual development
  • visual deficits

General

AFP beta-hCG Notes Age of Presentation
Seminoma - + in 15%-20% of patients 40's
Nonseminomatous Germ Cell Tumors
York Cell Tumor +++ - also called endodermal sinus tumor
Schiller-Duval bodies
Most common prepubescent GCT
Chriocarcinoma - +++ cytotrophoblasts
syncytiotrophoblasts
rare
Teratoma - - No extraembryonic elements
Embryonal Carcinoma +/- +/- may have extraembryonic components
half-life 5 days 22 hours

Embryonal Carcinoma

  • most undifferentialted
  • tumor necrosis and hemorrhage are frequently observed

Choriocarcinoma

  • By definition consists of Cytotrophoblasts and syncytiotrophoblasts
  • high levels of beta-hCG

Yolk Sack Tumor

  • also call endodermal sinus tumor
  • Associated with Schiller-Duval bodies
  • produces alpha-fetoprotein

Teratoma

  • two or more germ layers (ectoderm, mesoder, or endoderm)

Diagnosis of Intracranial Germ Cell Tumors

  • Its radiographic appearance and locaion may be characteristic at times (but need biopsy)
  • diagnosis require a biopsy, because of the absence of markers and the differences in management between germinoma and other tumor types

Treatment of Intracranial Germ Cell Tumors

Treatment of Germinoma

Chemotherapy

Intracranial germ cell tumors are chemosensitive
germinomas response rates ~100%
Example regiments

  • cyclophosphamide
  • carboplatin
  • cisplatin/vp-16
  • ICE (ifosfamide/carboplatin/VP-16)
  • CDDP/VP-16/bleomycin

Radiation Therapy

COG ACNS0232 Proposal
Control Arm

ARM Extent of Disease Initial Volume Total Dose to Primary
XRT only Local 24 Gy ventricular irradiation 45 Gy
XRT only Disseminated 30 Gy CSI 45

Experimental Arm

ARM Extent of Disease Initial Volume Total Dose to Primary
Chemo RT w/ CR Local N/A 30 Gy
Chemo RT w/ CR Disseminated 21 Gy CSI 30 Gy
Chemo RT w/ PR Local N/A 40.5 Gy
Chemo RT w/ PR Disseminated 24 Gy CSI 40.5 Gy
  • Alternating neoadjuvantchemotherapy for 4 cycles (cisplatin, VP-16, Vincristine, cytoxan)
  • Primary = GTV at diagnosis + 1-2 cm (also can include any areas of metastasis)
  • All radiation is given at 1.5 Gy per fraction

Unifocal Disease

  • Ventricular 24 Gy + Boost to 45 Gy

Multifocal Disease

  • multifocal seen on imaging
  • multifocal by inference (ie. pineal tumor with diabetes insipidus)
  • leptomeningeal spread
  • 2 cycles of chemo followed by
  • CSI 30 Gy + Boost to 45 Gy

Treatment of NGGCT

General

  • Combined chemoradiation approach should be used with NGGCT
  • Outcome with RT alone (10-30), Chemo alone (40-60%) are poor.

Current Trial By SIOP

  • Platinum based chemo for 16 weeks
  • Surgery if less than CR or BMT if less than PR. (ie. try to achieve minimal disease prior to RT)
  • CSI 36 Gy + Boost 54 Gy primary

Treatment of Mature Teratoma

  • Mature teratomas with malignant elements will be treated as germinomas.
  • Adjuvant chemotherapy and radiotherapy can be deferred if GTR is achieved in low-grade, immature teratomas but adjuvant therapies may be warranted for high-grade ones.[4]
Bibliography
1. Cox J, Ang K. Radiation Oncology: rationale Technique Results. 8th ed. New York: Mosby, 2003.
2. Gunderson L, Tepper J: Clinical Radiation Oncology. 2nd ed. China: Elsevier 2007.
3. Devita V, Hellman S, Rsenberg S: Cancer: Principles and practice of Oncology. 7th ed. Philadelphia: Lippincott, 2005.
4. Phi JH, Kim SK, Park SH, Hong SH, Wang KC, Cho BK. Immature teratomas of the central nervous system: is adjuvant therapy mandatory? J Neurosurg. 2005 Dec;103(6 Suppl):524-30. PMID: 16383251
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