[The importance of a complete diagnostic workup in patients with nontraumatic (partial) paraplegia]

In two women, aged 86 and 56 years, respectively, who suffered from back pain and loss of strength, and in a 55-year-old man who lost sensation and strength in his left leg, spinal-cord compression in connection with vertebral destruction was seen on radiological examination. When spinal-cord compression is the result of a local malignant tumour, the therapy often entails emergency radiotherapy. In the first two patients, histological examination revealed a solitary plasmocytoma and curative high-dose radiotherapy was applied. The third patient also had a lung tumour and received low-dose palliative radiotherapy to the vertebrae, as a metastasis was suspected. Later, however, histopathologic examination of the vertebral lesion revealed osteomyelitis due to Listeria monocytogenes and the lung tumour was diagnosed as a pT2N0M0 broncho-alveolar carcinoma which was surgically removed. When a patient is referred with a nontraumatic spinal-cord injury, it is important to complete the radiological and histological examinations before starting emergency radiotherapy in order to prevent an inadequate or even incorrect treatment.

Reirradiation of primary brain tumours: survival, clinical response and prognostic factors

BACKGROUND AND PURPOSE

First, the aim was to determine the survival and quality of life after reirradiation of relapsing primary malignant brain tumours. The second aim was to assess the influence of a set of potentially prognostic factors on survival.

MATERIALS AND METHODS

Forty-two patients received reirradiation for recurring primary brain tumours. The interval between the two consecutive treatments was at least 1 year. External beam irradiation for the initial and recurrent tumour was usually delivered with two opposing lateral fields or two wedged fields in orthogonal directions. The median physical doses of the first and second radiation course were 50 and 46 Gy, respectively. The median cumulative biological equivalent doses (BED) were 200.4 (alpha/beta = 2 Gy) and 115.2 Gy (alpha/beta = 10 Gy). During follow-up, corticosteroid medication and the WHO-performance were registered at regular intervals. The radiological response was assessed by reviewing all available CT- and MRI-films. Potentially prognostic factors with respect to survival were evaluated by both univariate and multivariate analyses.

RESULTS

A clinical response (i.e. clinical improvement) was seen in 24% of the patients. Of the evaluable patients, nearly one-third showed a complete (8%) or partial (22%) radiological response. The median overall survival (OS) and progression-free survival (PFS) after retreatment were 10.9 and 8.6 months, respectively. By multivariate analysis, four independent prognostic factors for survival were identified: (1), the WHO-score before retreatment (P = 0.002); (2), the length of the interval between treatments (P = 0.008); (3), the tumour histology; and (4), the response to initial treatment (P values, 0.04). The median survival times for patients with WHO-scores of 0-1 and > or = 2 were 14.0 and 7.4 months, respectively. Patients with oligodendrogliomas had a median OS of 27.5 months, whereas patients with astrocytomas had a median OS of 6.9 months after retreatment. Long-term complications of retreatment were seen in three patients, all of whom had a cumulative BED(2) of > 204 Gy (with alpha/beta = 2 Gy). The quality of life after retreatment, however, was well preserved in the majority of patients. They remained ambulant and capable of self-care until the time of progression which occurred after 8.6 months (median PFS).

CONCLUSIONS

After an initial treatment with radiation up to tolerance levels of normal brain tissue, reirradiation of recurring primary brain tumours seems feasible. During the time until clinical progression, patients remained independent with a reasonable quality of life.

Combined modality treatment is the treatment of choice for stage I/IE intermediate and high grade non-Hodgkin's lymphomas

BACKGROUND AND PURPOSE

In a retrospective study, the efficacy of radiotherapy alone was compared with combined modality treatment in patients with stage I/IE non-Hodgkin's lymphoma (NHL).

PATIENTS AND METHODS

Between 1980 and 1994, 296 patients with stage I/IE non-Hodgkin's lymphoma of intermediate or high grade malignancy (according to the Working Formulation) were treated in four different institutions. All patients were included except patients that presented with NHLs localized in the central nervous system, testis or skin. Two hundred two patients were treated with radiation therapy alone and 94 patients were treated with combined modality treatment.

RESULTS

Increasing age and radiation as a single treatment (versus combined modality treatment) were highly significant adverse prognostic factors by multivariate analysis. The actuarial 10-year rates for progression-free and overall survival were 83 and 70%, respectively, for the patients treated with combined modality treatment and 47 and 43%, respectively, for the patients treated with radiation therapy alone.

CONCLUSION

Combined modality treatment is the treatment of choice for patients with stage I/IE intermediate and high grade non-Hodgkin's lymphomas.

A randomized controlled clinical trial on the efficacy of radiation therapy in the control of subfoveal choroidal neovascularization in age-related macular degeneration: radiation versus observation

BACKGROUND

The results of several pilot studies concerning radiation therapy for age-related subfoveal choroidal neovascularization (CNV) have been published recently. Although positive treatment results have been described, it is not known whether this therapy alters the natural course of eyes with neovascular age-related macular degeneration (AMD). A randomized controlled clinical trial was conducted in which radiation therapy was compared with observation in patients with subfoveal neovascular AMD.

METHODS

Seventy-four patients with a recent drop in central vision due to subfoveal age-related CNV were randomized to either radiation treatment or observation. Patients with either classic, occult or mixed type CNV were included. Eyes in the treatment group received a radiation dose of 24 Gy in four fractions of 6 Gy. Evaluation of data concerning visual acuity (VA) and fluorescein angiography occurred at 3, 6 and 12 months after inclusion.

RESULTS

At 12 months of follow-up 52.2% of the observation group versus 32.0% of the irradiation group had lost 3 or more lines of VA (P = 0.03, log rank test). More severe visual decline, 6 lines or more, was observed in 40.9% of the observation versus 8.8% in the irradiation group (P = 0.002 using log rank test). At 12 months 39.6% of the observation group and 20.0% of the treatment group had VA of less than 0.1 (P = 0.08, log rank test). The size of the CNV membrane doubled in 25.2% of eyes in the observation group versus 20.0% in the treatment group at least 12 months (P = 0.5, log rank test). No side effects were observed.

CONCLUSION

Preservation of VA was significantly better in the treatment group compared with the control group at 12 months. Nevertheless we noted a drop in central vision of 3 or more lines in a substantial proportion of the treatment group. Radiation therapy does not prevent visual loss in all patients with age-related subfoveal CNV, and whether the treatment benefit at 12 months will persist has to be awaited.

Allogeneic bone marrow transplantation with T-cell-depleted marrow grafts for patients with poor-risk relapsed low-grade non-Hodgkin's lymphoma

We present the clinical results of allogeneic bone marrow transplantation (BMT) with T-cell-depleted grafts from HLA-matched sibling donors in patients with poor-risk relapsed low-grade non-Hodgkin's lymphoma (NHL). Poor risk was defined as relapse within 12 months after or progression during prior treatment. The conditioning regimen consisted of cyclophosphamide and total-body irradiation with or without additional idarubicin. Donor marrow was depleted of T lymphocytes using counterflow centrifugation. Post-BMT prophylaxis of graft-versus-host disease (GvHD) consisted of cyclosporine A. 15 patients with a median age of 47 years (range 30-57) were transplanted. All patients engrafted. After a median follow-up of 36 months (range 9-78), 10 patients were alive and in complete remission (CR). Two of them had relapsed after BMT but re-entered CR following infusions of leucocytes from the original bone marrow donor. Five patients died; causes of death were cardiomyopathy (n = 1), chronic GvHD (n = 1) and infection during chronic GvHD (n = 3). We conclude that allogeneic T-cell-depleted bone marrow transplantation is an efficacious treatment for patients with poor-risk relapsed low-grade NHL. Infusions of donor leucocytes reinduced CR in the two patients with relapse after BMT.

[The success of lymphocyte infusion as treatment of leukemia recurrence following allogeneic bone marrow transplantation depends on low percentage of patient's own lymphocytes]

OBJECTIVE

Evaluation of induction of complete remission with infusion of lymphocytes from the original bone marrow donor in patients with leukaemia which relapsed after allogeneic bone marrow transplantation.

SETTING

Division of Haematology, University Hospital Nijmegen and the Red Cross Blood Bank Nijmegen, the Netherlands.

DESIGN

Prospective, non-randomized study.

METHODS

Twenty-eight patients who relapsed after allogeneic bone marrow transplantation were treated with infusion of lymphocytes from the original bone marrow donor. Lymphocytes were collected by means of leukapheresis. Follow-up was done by frequent checks at the outpatient clinic.

RESULTS

Eleven of 15 (73%) patients with relapsed chronic myeloid leukaemia (CML) and only one of 13 patients (8%) with a relapse of acute leukaemia went into complete remission (p < 0.001). Entering complete remission was always preceded by acute or chronic graft-versus-host disease (GVHD). The development of acute and/or chronic GVHD was significantly associated with the origin of T-lymphocytes in the blood of the recipient at the time of infusion. If the T-lymphocytes came mostly from the patient himself, the infusion remained usually without effect. If the T-lymphocytes came mostly from the donor, the patients went into complete remission.

CONCLUSION

Patients with a relapse of leukaemia after allogeneic bone marrow transplantation may enter complete remission after infusion of lymphocytes from the original marrow donor. This form of immunotherapy can be successful especially in patients with a relapsed CML with a relatively low percentage of autologous T-lymphocytes at the time of infusion.

Visual acuity and scar size in eyes with age-related subfoveal choroidal neovascular lesions, 30 months after radiation therapy

PURPOSE

In a study to determine the effectiveness of ionizing radiation on the deterioration of visual acuity (VA) due to choroidal neovascularisation (CNV) the affected eyes of 10 patients were treated with a total dose of 24 Gy (6 Gy fractions). A special lens-sparing technique was used to avoid cataract development. During 30 months of follow-up the visual acuity (VA) and scar size (SS) of the treated eyes and fellow eyes of all 10 patients were evaluated.

RESULTS

After 30 months of follow-up 5 eyes showed a stable VA and fluorescein angiogram (FA) appearance. Concerning 4 out of 5 eyes with progressive disease, the 4 eyes treated with radiation therapy had better VA and smaller SS as compared with the untreated fellow eyes with exudative AMD.

CONCLUSIONS

The results suggest that 24 Gy either stabilizes or delays the deleterious effects of CNV on the visual acuity. Until now no late side effects have been observed.

Radiotherapy with carbogen breathing and nicotinamide in head and neck cancer: feasibility and toxicity

The feasibility and early toxicity of radiotherapy with carbogen breathing and nicotinamide was tested in 74 head and neck cancer patients. Forty patients with laryngeal and hypopharyngeal tumors were treated with an accelerated schedule combined with carbogen alone (16) or with carbogen and nicotinamide (24). Thirty-four patients with far advanced unresectable tumors of the oral cavity and oropharynx received conventional radiotherapy with carbogen [16] or with carbogen and nicotinamide (18). Some enhancement of skin reaction was observed with nicotinamide but this remained well within limits of tolerance. With the accelerated regimen there was increased severity of mucosal damage expressed as confluent mucositis in 95% of patients which required healing times of 3-4 months in four patients. Eventually restoration of the mucosal lining was complete in all cases. Nausea and vomiting are the most frequent side effects of nicotinamide and were reported by 60% and 36% of the subjects, respectively. In 26% this was reason to discontinue drug intake. Severe renal dysfunction was associated with nicotinamide intake in two patients of this study and in one other patient who presented later. It is our conclusion that radiotherapy combined with carbogen and nicotinamide is a safe treatment with manageable side effects. We recommend not to give nicotinamide concomitantly with nephrotoxic medication or to patients who have impaired renal function. Preliminary tumor control rates are encouraging and clinical testing will be continued.

Conventional radiotherapy combined with carbogen breathing and nicotinamide for malignant gliomas

High grade malignant gliomas are among the most radioresistant human tumors and total doses up to 80 Gy are inadequate to achieve long-term local control in most of the patients. Hypoxia has been demonstrated in primary brain tumors and may be one of the reasons for their radioresistance. In experimental models carbogen breathing and nicotinamide have been shown to act against hypoxia by different mechanisms and both modalities were tested in 16 patients with supratentorial malignant gliomas in combination with a conventional radiotherapy scheme (50 Gy in 25 daily fractions). The present study was performed to determine the feasibility and toxicity of conventional radiotherapy combined with carbogen breathing and nicotinamide. The unexpectedly high incidence of acute liver toxicity, the possible increase of subacute and late CNS toxicity, and the absence of a higher effectivity led us to reconsider this new treatment modality for patients with malignant gliomas.

Radiation therapy for subfoveal choroidal neovascular membranes in age-related macular degeneration. A pilot study

BACKGROUND

The natural course of the visual acuity of age-related subfoveal choroidal neovascularisation (CNV) membranes is poor. Laser photocoagulation of subfoveal CNV is recommended if the patient is willing to accept a large decrease in visual acuity immediately after treatment. A large proportion of patients with subfoveal CNV do not meet the Macular Photocoagulation Study Group (MPS) guidelines for laser photocoagulation. The fact that so few patients meet these criteria makes further research into new treatment techniques warranted. Ionising radiation may prevent the proliferation of endothelial cells of newly formed subretinal capillaries and may induce obliteration of the aberrant new vessels.

METHODS

In this study, the effect of radiation therapy on subfoveal CNV membranes was evaluated. Four groups of ten patients were treated with external beam radiotherapy (16-MV photons) on an area of 1 cm2 (macular region) using a lens-sparing technique and total doses of 8-24 Gy. The first group received 8 Gy in one fraction. The second, third and fourth groups received 12 Gy in 2 fractions, 18 Gy in three fractions and 24 Gy in four fractions respectively. The studied parameters included best-corrected visual acuity and membrane size and leakage on the fluorescein angiogram. We included 17 occult and 23 classic CNV membranes as defined by the MPS, with a duration of less than 5 weeks at presentation. Complete ophthalmic examination including fluorescein angiography was performed before and 3, 12 and 18 months after radiation treatment. We analysed the angiogram using a standard overprojection sheet. The results concerning the visual acuity and fluorescein angiography (FA) were compared with the extensively published, natural course data.

RESULTS

The first group (including three cases of occult CNV) received 8 Gy in a single fraction. In this group only four of ten patients had stable visual acuity and stable FA appearance after 21 months follow-up. The visual acuity and FA remained stable after 13.6 months follow-up in seven of the patients in group 2 (12 Gy in two fractions, four occult CNV). The third group (18 Gy in three fractions, seven occult CNV) contained six patients with stable visual acuity, although two of them had CNV deterioration on the FA (11.1 months follow-up). In the last group (24 Gy in four fractions, three occult CNV), with a short follow-up of 5.6 months, eight patients had stable visual acuity and FA appearance. We did not note any regression of the CNV membrane on the angiogram. The visual acuity in groups 2, 3 and 4 decreased to 0.1 or worse in only three cases, three cases and one case respectively after at least 6 months follow-up.

CONCLUSION

Comparison of these findings with the natural history data of subfoveal age-related CNV suggests a beneficial effect of radiation therapy with a total dose of 12 Gy or more on the progression of CNV. To date no negative side effects have been observed.

A convenient and reliable method for carbogen breathing in man

The feasibility of carbogen breathing and the intake of nicotinamide in combination with radiation therapy is currently being tested for clinical application. A dependable and convenient system for carbogen breathing is presented which can be easily combined with techniques for immobilization of the patient. The proposed method ensures adequate breathing of carbogen.

Repair capacity of adult rat glial progenitor cells determined by an in vitro clonogenic assay after in vitro or in vivo fractionated irradiation

Demyelination is one of the pathological conditions identified as a late response of the central nervous system (CNS) to irradiation. We have proposed that radiation-induced depletion of glial stem cells, which are the source of myelinating cells in the CNS, would lead to a lack of replacement of senescent or otherwise damaged oligodendrocytes. This impaired process of cell renewal would result in a decline of oligodendrocytes, i.e. demyelination. In the present study the repair capacity of glial stem cells was investigated and compared with the repair capacity of the CNS in vivo using functional endpoints. For this purpose, glial stem cells, derived from the adult rat optic nerve, were subjected to fractionated irradiation in vivo and in vitro and their survival was quantified with an in vitro clonogenic assay. The data were analysed by three different methods, all based on the LQ-model (single dose survival curve; 'beta RR', 'Fe-plot'). The resulting value of the beta-parameter of adult glial stem cells is consistent with values obtained for functional endpoints after irradiation of the CNS in vivo. The alpha/beta-ratio (4.9-7.3 Gy) of adult glial stem cells, however, is higher than the alpha/beta-ratio (approximately 2 Gy) obtained for CNS in vivo and is closer to that of an acute responding tissue.

Repopulation of O-2A progenitor cells after irradiation of the adult rat optic nerve analyzed by an in vitro clonogenic assay

In the central nervous system (CNS) O-2A (Oligodendrocyte type 2 Astrocyte) progenitor cells have been proposed as potential target cells, and their depletion by irradiation will cause demyelination. The extent and time course of repopulation of these glial stem cells were studied in the adult rat optic nerve after irradiation in vivo. The number of O-2A progenitor cells was measured quantitatively by an in vitro clonogenic assay. Although the CNS is typically a late-responding tissue, repopulation was initiated almost immediately after irradiation and after several weeks a plateau was reached that lasted up to 6 months. Single doses of 4-12 Gy of X rays caused a permanent reduction in the number of O-2A progenitor cells. An analysis of the colony size of O-2A progenitor cells showed a sustained reduction in the number of offspring of cells surviving a dose of 12 Gy. In addition, the colony size of unirradiated progenitors diminished with increasing age of the animals.

Irradiation in vitro discriminates between different O-2A progenitor cell subpopulations in the perinatal central nervous system of rats

The effects of X irradiation on oligodendrocyte-type-2-astrocyte (O-2A) progenitor cells derived from different regions of the perinatal central nervous system (CNS) of rats were investigated in vitro. The O-2A progenitor cells can differentiate into either oligodendrocytes or type-2 astrocytes. The depletion of these cells could lead to demyelination, seen as a delayed reaction after irradiation of the CNS in vivo. To quantify cell survival, O-2A progenitor cells were grown on monolayers of type-1 astrocytes. Monolayers of type-1 astrocytes stimulate O-2A progenitor cells to divide. O-2A progenitor cells were irradiated in vitro and clonogenic cell survival was measured. The O-2A progenitor cells derived from perinatal optic nerve were quite radiosensitive in contrast to O-2A progenitor cells derived from perinatal spinal cord and perinatal corpus callosum. Furthermore, O-2A progenitor cells derived from the optic nerve formed smaller colonies, with most colonies showing early differentiation into oligodendrocytes. In contrast, more than half of the colonies derived from corpus callosum did not show any differentiation after 2 weeks in vitro and kept growing. These differences support the view that perinatal O-2A progenitor cells derived from the optic nerve are committed progenitor cells while the O-2A progenitor cells derived from the perinatal corpus callosum and the perinatal spinal cord have more stem cell properties.

Radiosensitivity of glial progenitor cells of the perinatal and adult rat optic nerve studied by an in vitro clonogenic assay

The cellular basis of radiation-induced demyelination and white matter necrosis of the central nervous system (CNS), is poorly understood. Glial cells responsible for myelination in the CNS might be the target cells of this type of damage. Glial cells with stem cell properties derived from the perinatal and adult rat CNS can be cultured in vitro. These cells are able to differentiate into oligodendrocytes or type-2 astrocytes (O-2A) depending on the culture conditions. Growth factors produced by monolayers of type-1 astrocytes inhibit premature differentiation of O-2A progenitor cells and allow colony formation. A method which employs these monolayers of type-1 astrocytes to culture O-2A progenitor cells has been adapted to allow the analysis of colonies of surviving cells after X-irradiation. In vitro survival curves were obtained for glial progenitor cells derived from perinatal and adult optic nerves. The intrinsic radiosensitivity of perinatal and adult O-2A progenitor cells showed a large difference. Perinatal O-2A progenitor cells are quite radiosensitive, in contrast to adult O-2A progenitor cells. For both cell types an inverse relationship was found between the dose and the size of colonies derived from surviving cells. Surviving O-2A progenitor cells maintain their ability to differentiate into oligodendrocytes or type-2 astrocytes. This system to assess radiation-induced damage to glial progenitor cells in vitro seems to have a great potential in unraveling the cellular basis of radiation-induced demyelinating syndromes of the CNS.

An in vitro clonogenic assay to assess radiation damage in rat CNS glial progenitor cells

Normal glial progenitor cells can be isolated from the rat central nervous system (CNS) and cultured in vitro on a monolayer of type-1 astrocytes. These monolayers are able to support and stimulate explanted glial progenitor cells to proliferate. Employing these in vitro interactions of specific glial cell types, an in vivo-in vitro clonogenic assay has been developed. This method offers the possibility to study the intrinsic radiosensitivity, repair and regeneration of glial progenitor cells after in vitro or in vivo irradiation.