Radiation therapy in patients with AIDS-related central nervous system lymphomas

Utility of brain biopsy in patients with acquired immunodeficiency syndrome before and after introduction of highly active antiretroviral therapy

OBJECTIVE

This study investigates the changing indications, results, and practice patterns of brain biopsy in patients with acquired immunodeficiency syndrome (AIDS) as treatment evolved with the development of highly active antiretroviral therapy (HAART).

METHODS

We collected data on 246 patients with AIDS who were undergoing brain biopsy of intracranial lesions. Patients were managed in accordance with a uniform protocol. Patients were divided into two groups of those biopsied in the era before (1992-1996) or after (1997-2001) the use of HAART.

RESULTS

The introduction of HAART led to a steep decrease in the number of biopsies performed annually. The protocol functioned well. Diagnoses were obtained for 92.3% of patients. Lymphoma was the most frequent diagnosis (52.9% of patients), followed by progressive multifocal leukoencephalopathy (18.9% of patients) and toxoplasmosis (8.1% of patients). No patient who underwent lesion biopsy for reasons of negative toxoplasmosis titers or atypical radiology evaluation was diagnosed with toxoplasmosis. Nineteen patients who experienced failed toxoplasmosis treatment were diagnosed with toxoplasmosis. Toxoplasmosis titers had a high specificity and a negative predictive value. Patients with progressive multifocal leukoencephalopathy or nondiagnostic biopsies were more likely to have solitary lesions. The average Karnofsky performance score at the time of biopsy was 72.4, which is still within the range of independent functioning. Significant intracerebral hemorrhages were only observed in patients with lymphoma who also had low platelet counts.

CONCLUSION

Although the number of patients with AIDS who require brain biopsy has decreased, the procedure still has merits. The paradigm we developed was useful for selecting patients for early biopsy. Patients with AIDS who also have intracerebral lesions should have toxoplasmosis titers performed, and those whose titers are negative for toxoplasmosis should undergo early brain biopsy.

Acquired immunodeficiency syndrome-related primary cerebral lymphoma: response to irradiation

Acquired immunodeficiency syndrome-related primary cerebral lymphoma (AIDS-PCL) is uncommon. Fourteen cases of presumed AIDS-PCL between 1986 and 1995 were reviewed retrospectively in order to characterize the natural history, and the response to radiotherapy. The median age was 38 years (range 24-65). The median interval between seropositive diagnosis of HIV and AIDS-PCL was 28 months (range 5-113). The median duration of symptoms was 2 weeks (range 0.2-12). At presentation, the Eastern Cooperative Oncology Group performance status (PS) was PS1 (2/14 patients), PS2 (6/14) and PS3 (6/14). The symptoms and signs were non-specific and depended on the site and extent of cerebral involvement. There was no characteristic pattern of brain imaging in terms of size, number, location or pattern of contrast enhancement of the cerebral lesions. Nine patients received various fractionation-dose schedules (range 8-50 Gy). Complete and partial responses were seen in 2/9 and 3/9 cases, respectively. Clinical stabilization of neurological symptoms was noted in 3/9 cases and disease progression in 1/9. The median survival times (MST) from presentation for irradiated and non-irradiated patients were 9.3 and 2.1 weeks, respectively (range 0.9-43.1). Although patient selection introduced bias, there appears to be a modest improvement in MST for treated patients. The MST with radiotherapy alone remains poor, but radiotherapy may provide palliation. For some selected patients, a prolonged response is possible.

AIDS-related malignancies

In the US over one million persons are currently infected with the HIV, over half a million have had AIDS, and over 300,000 have died from AIDS. Worldwide, it is estimated that more than 17 million people are currently infected with HIV, and over 1,200,000 cases of AIDS have been reported to the World Health Organization. By some estimates, up to 40% of patients with AIDS will ultimately develop some form of cancer. Non-Hodgkin's lymphoma, Kaposi's sarcoma and invasive cervical cancer have a higher incidence in persons with HIV infection and all three are AIDS-defining illnesses. In addition, several reports suggest that a number of other malignancies may occur at an increased incidence in persons with HIV infection, including squamous-cell carcinoma of the head, neck and anus, plasmacytoma, melanoma, small-cell lung cancer, basal-cell cancer, and germ-cell tumours. Clinicians should become familiar with HIV-related malignancies as their incidence is expected to further increase as more effective therapies for HIV and associated opportunistic infections allow patients to live longer in an advanced state of immunodeficiency. In the current article, we will review the clinical and therapeutic aspects of the most common AIDS-related malignancies including non-Hodgkin's and Hodgkin's lymphomas, Kaposi's sarcoma and anogenital epithelial neoplasias.

Neurologic manifestations of HIV infection

A wide spectrum of central and peripheral nervous system abnormalities may be associated with HIV infection. These disorders may be caused by HIV infection, result as secondary complications related to immunosuppression, or be a neurotoxic effect of therapeutic agents. The range of neurologic disorders includes dementia, focal cerebral mass lesions, myelopathy, peripheral neuropathies, and myopathy. Early diagnosis and therapy is critical, and may result in substantial improvement in patients' quality and quantity of life. This article reviews the approach to differential diagnosis of these neurologic disorders and presents theories of pathogenesis and current approaches to treatment.

Non-Hodgkin's lymphomas (NHL)

This synthesis of the literature on radiotherapy for non-Hodgkin's lymphomas is based on 158 scientific articles, including 16 randomized studies, 18 prospective studies, and 90 retrospective studies. These studies involve 14,137 patients. Non-Hodgkin's lymphomas are highly radiosensitive, and local recurrence following radiotherapy is unusual. Radiotherapy probably cures approximately 50% of both low-grade and high-grade malignant NHL at stage I. Involved field is apparently sufficient, however, higher doses are required for high-grade malignant lymphomas. Chemotherapy is recommended for stage II. Consolidation radiotherapy after chemotherapy may increase the number of complete remissions. The value of adjuvant radiotherapy has not been confirmed. Radiotherapy plays a limited role at stages III and IV. Radiotherapy is clearly indicated for extranodal localized disease in the skin and in the orbit of the eye. It is important to identify groups and subgroups in whom radiotherapy alone is sufficient, ie, the risk for distant recurrence is small. MALT lymphoma belongs to this group. Radiotherapy is often valuable in palliative situations.

HIV-related non-Hodgkin's lymphoma among European AIDS patients. AIDS in Europe Study Group. AIDS in Europe Study Group

The epidemiology of HIV associated non-Hodgkin's lymphoma (NHL) was investigated in 6550 European patients with AIDS. NHL was diagnosed in 3.5% of all patients at the time of the AIDS diagnosis. Although the probability of being diagnosed with NHL at AIDS diagnosis was significantly higher among intravenous drug users than among homosexual men, and was associated with increasing age, the observed incidences of NHL were more strikingly similar than any differences. The rate of developing NHL after a previous AIDS diagnosis was 2.4 per 100 patient years of follow-up, and remained constant during a 5-year follow-up period. While primary brain lymphomas comprised only 9% of NHL diagnosed at the time of AIDS, they comprised 38% of NHL diagnosed after AIDS (p < 0.001). The prognosis for patients with NHL at AIDS diagnosis was poor with a median survival of 5 months. A diagnosis of primary brain lymphoma was uniformly associated with a poor outcome. It is concluded that the probability of developing NHL in late stage HIV infection is lower than previously anticipated from the results of small studies on patients receiving long-term anti-retroviral therapy.