CNS Tumors Lymphoma

CNS LYMPHOMA

  • Primary CNS Lymphoma
  • Rare type of NHL but increasing in frequency
  • HIV-associated cases but most occurred in immunocompentent patients
  • Median age is 55 years old

Imaging

  • Isodense or hyperdense on nonenhanced CT
  • Isointense signal on pre-gadolinium T1
  • Post-gadolinium, there is dense and diffuse enhancement
  • Sometimes described as “cotton-wool”
  • MR image of PCNSL can be diagnostic.
  • indistinct borders with variable edema
  • ring enhance is rarely seen

IELSG Prognostic factors for OS

  • > 60 years old.
  • ECOG 2 or higher
  • Elevated LDH
  • Elevated CSF
  • Involvement of deep brain structures
! # factors 2 year OS
0 to 1 80%
2 to 3 48%
4 to 5 15%

RTOG RPA Classes for CNS Lymphoma

  • KPS
  • AGE
  • BRAIN ONLY DISEASE

PROGNOSIS by TREATMENT

  • Treatment OS-5
  • RT alone 10%
  • Chemo+/- RT 20%

GENERAL

  • Increased with HIV, EBV
  • AIDS associated CNS lymphomas are worse with 100% multifocal disease (40% in immunocompetent patients)
  • 50-70 years
  • Supratentorial and Paraventricular in region
  • 42% have CSF spread[3](p.2012)
  • 100% CSF infiltration with HIV
  • 20% have ocular lymphoma

PATHOLOGY

  • Perivascular cuffs and sheets of lymphoid tumor cells into the Virchow-Robin spaces.
  • Predominantly B cells (usually large cell, immunoblastic subtype).

DIAGNOSIS

  • Spinal MRI
  • CSF fluid
  • H/P with assessment with fundoscopic exam.
  • Biopsy

MRI

  • Isodense or hyperdense on nonenhanced CT
  • Sometimes described as “cotton-wool”
  • Most occur in periventricular distribution usually involving the corpus callosum, thalamus, or basal ganglia, may be multifocal in HIV patients
  • DLBCL is the most common type

TREATMENT

Medications

  • steroid delivers 90% response.

Surgery

  • Surgical resection adds little due to tumors infiltrative nature
  • prolongs survival from 2 months to 4 months survival

Chemotherapy ALONE

  • Protocols using Chemotherapy: MTX (> 3 g/m2) IV in various combination with carmustine, procarbazine, vincristine, and dexamethasone have produced impressive results without RT and with mild to moderate late neurologic toxicity. MTX (> 3 g/m2) alone gives 20% five year survival rate with median survivals in 30-40 months.

Chemo + WBRT Indications

  • < 45 years old with good PS
  • DO NOT GIVE in patient > 60 years-old.

Chemo + WBRT Studies

  • RTOG 9310 CT + 45 Gy WBRT superior to historical WBRT
  • Journal of Clinical Oncology, Vol 20, Issue 24 (December), 2002: 4643-4648
  • CT DOSE: methotrexate 2.5 g/m2, vincristine, procarbazine, and intraventricular methotrexate (12 mg).
  • RT DOSE and FIELD: total dose of 45 Gy WBRT in 1.80-Gy fractions with a total dose of 36 Gy in 20 fractions both eyes for ocular involvement.
  • To date best results have been achieved with MTX-IV (Intra-Ommaya), Vincristine and procarbazine prior to WBRT with median OS of 60 months. In this MSK regimen high-dose cytarabine is given after the radiation is complete. Radiation starts in week 11 of treatment.

Toxicity w/ CHEMO + WBRT

  • DeAngelis (MSK)
  • J Neurooncol. 1999 Jul;43(3):249-57.
  • High-dose methotrexate combined with cranial irradiation yields a median survival of at least 40 months and five year survival rates of 22%. However, neurotoxicity is substantial in a significant proportion of patients, particularly those over the age of 60 at the time of treatment. As many as 50% of such patients develop severe dementia. Neurotoxicity of ~ 100% in patients older than 60 y.o. 24 mo. Post diagnosis vs. 30% in patients < 60 y.o. **WBRT

MTX is toxic to > 60 y.o. patients (cognitive)**. Combined modality may be considered in patients < 60.

Radiation ALONE

  • Given in patients with poor PS or Cr Clearance (Unable to receive Chemo)
  • WBRT to 45 Gy with Spinal RT for LP or MR positive patients

SALVAGE WBRT

  • For patients failing chemotherapy, RT as salvage therapy remains useful with response rate of 74%. ( J Clin Oncol. 2005 Mar 1;23(7):1507-13.)
  • Avoid RT in patients over 60 years of age when possible
  • If eye exam positive, monitor carefully for response to treatment. Consider RT to orbits or intraorbital chemotherapy.

Historical WBRT

  • RTOG 8315 delivered 60Gy with 1-year survival of 50% and median survival at 1 year. However, other studies show < 10% long term survival due to distant failures and CNS recurrences.
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.
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