moyamoya syndrome following childhood acute lymphoblastic leukemia

5
Pediatr Blood Cancer 2007;48:268–272 Moyamoya Syndrome Following Childhood Acute Lymphoblastic Leukemia Akira Kikuchi, MD, PhD,* Miho Maeda, MD, Ryoji Hanada, MD, Yuri Okimoto, MD, PhD, Koichi Ishimoto, MD, PhD, Takashi Kaneko, MD, PhD, Koichiro Ikuta, MD, and Masahiro Tsuchida, MD, PhD On behalf of the Tokyo Children’s Cancer Study Group (TCCSG) INTRODUCTION To date, the prognosis of childhood acute lymphoblastic leukemia (ALL) has improved considerably [1 –3]. However, as the number of long-term survivors has been increasing, adverse sequelae have emerged as serious problems for the quality of life (QOL) of these patients [4]. Moyamoya disease is characterized by stenotic and occlusive changes in the bilateral internal carotid arteries and their rich arterial collaterals at the base of the brain. Diagnostic criteria of Moyamoya disease are shown in Table I [5]. It predominantly occurs in Asians and in children, although the cause of genetic susceptibility to Moyamoya disease in Asian is totally unknown. Signs and symptoms include mental and physical deterioration such as conscious- ness disturbance or convulsions as the result of brain hypoperfusion. In some cases, it may be fatal. If the patients have a known systemic disease or a history of cranial insults, these cases are referred as moyamoya syndrome (MoS) or quasi-moyamoya disease. The Tokyo Children’s Cancer Study Group (TCCSG) conducted four consecutive ALL treatment protocols (L84- 11, L89-12, L92-13, and L95-14) between 1984 and 1999, and follow-up studies of long-term survivors [6–9]. In this series, we identified six MoS patients who had experienced childhood ALL. Here we report the clinical course of MoS and the prognosis of these patients in relation to the primary disease and ALL treatment. PATIENTS AND METHODS A total of 1,846 ALL patients were treated with four consecutive TCCSG ALL protocols (L84-11, L89-12, L92- 13, and L95-14) between 1984 and 1999. Briefly, these protocols consisted of remission induction therapy using prednisolone or dexamethasone, vincristine and L-asparagi- nase with or without cyclophosphamide and anthracyclines, consolidation therapy, BFM (Berlin-Frankfurt-Munster)- style reinduction therapy and maintenance therapy. The duration of each protocol ranged from 1 year (L92-13) to 3½ years (L84-11). For prophylaxis of central nervous system (CNS) leukemia, cranial irradiation or high dose methotrex- ate (HD-MTX) with intrathecal injections were used according to the criteria of each protocol. Table II shows the number of patients who were treated with each protocol and who received prophylactic cranial irradiation. Patient age ranged from 1 to 15 years at diagnosis of ALL. All treatments were performed with informed consent from the patients’ guardians. To evaluate the QOL of long-term survivors, information about late complications was collected at annual follow-up investigation. The median follow-up period for these patients was 8 years and 8 months. For statistical analysis, Chi-square tests were used to analyze the relationships between MoS and clinical data. Background. Long-term survivors of childhood acute lympho- blastic leukemia (ALL) sometimes suffer from adverse long-term sequelae. We analyzed the incidence, clinical course and prognosis of moyamoya syndrome (MoS) following childhood ALL. Procedure. A total of 1,846 ALL patients were treated with four consecutive TCCSG ALL protocols (L84-11, L89-12, L92-13, and L95-14) between 1984 and 1999. We surveyed the MoS cases among these patients in the follow-up studies. Results. Six patients with MoS were identified: four boys and two girls whose ages ranged from 2 years and 1 month (abbreviated as ‘‘2y1m’’) to 14y 1 m at diagnosis of ALL. None of the patients had central nervous system (CNS) leukemia. All six patients received prophylactic cranial irradiation with a dosage of 18 or 24 Gy. Although one patient died of brain infarction due to MoS, no leukemic relapse was observed in the group. The cumulative incidence of MoS in our series was 0.46 0.02% at 8 years. Among several clinical characteristics, use of cranial irradiation was the only factor that appeared to be significantly related to the development of MoS. Conclusions. MoS occurs with increased frequency in children treated for ALL, and might be asso- ciated with cranial irradiation. Prophylactic cranial irradiation should be used cautiously in ALL patients who can be cured by other CNS-directed therapies. Pediatr Blood Cancer 2007;48:268– 272. ß 2006 Wiley-Liss, Inc. Key words: childhood acute lymphoblastic leukemia; Moyamoya syndrome; prophylactic cranial irradiation; vasculopathy ß 2006 Wiley-Liss, Inc. DOI 10.1002/pbc.20837 —————— Division of Hematology/Oncology, Saitama Children’s Medical Center, Saitama, Japan *Correspondence to: Akira Kikuchi, Division of Hematology/ Oncology, Saitama Children’s Medical Center, 2100 Magome Iwatsuki-ku Saitama-shi, Saitama 339-8551, Japan. E-mail: [email protected] Received 25 September 2005; Accepted 14 February 2006

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Page 1: Moyamoya syndrome following childhood acute lymphoblastic leukemia

Pediatr Blood Cancer 2007;48:268–272

Moyamoya Syndrome Following Childhood AcuteLymphoblastic Leukemia

Akira Kikuchi, MD, PhD,* Miho Maeda, MD, Ryoji Hanada, MD, Yuri Okimoto, MD, PhD, Koichi Ishimoto, MD, PhD,Takashi Kaneko, MD, PhD, Koichiro Ikuta, MD, and Masahiro Tsuchida, MD, PhD

On behalf of the Tokyo Children’s Cancer Study Group (TCCSG)

INTRODUCTION

To date, the prognosis of childhood acute lymphoblastic

leukemia (ALL) has improved considerably [1–3]. However,

as the number of long-term survivors has been increasing,

adverse sequelae have emerged as serious problems for the

quality of life (QOL) of these patients [4].

Moyamoya disease is characterized by stenotic and

occlusive changes in the bilateral internal carotid arteries

and their rich arterial collaterals at the base of the brain.

Diagnostic criteria of Moyamoya disease are shown in

Table I [5]. It predominantly occurs in Asians and in children,

although the cause of genetic susceptibility to Moyamoya

disease in Asian is totally unknown. Signs and symptoms

include mental and physical deterioration such as conscious-

ness disturbance or convulsions as the result of brain

hypoperfusion. In some cases, it may be fatal. If the patients

have a known systemic disease or a history of cranial insults,

these cases are referred as moyamoya syndrome (MoS) or

quasi-moyamoya disease.

The Tokyo Children’s Cancer Study Group (TCCSG)

conducted four consecutive ALL treatment protocols (L84-

11, L89-12, L92-13, and L95-14) between 1984 and 1999,

and follow-up studies of long-term survivors [6–9]. In this

series, we identified six MoS patients who had experienced

childhood ALL. Here we report the clinical course of MoS

and the prognosis of these patients in relation to the primary

disease and ALL treatment.

PATIENTS AND METHODS

A total of 1,846 ALL patients were treated with four

consecutive TCCSG ALL protocols (L84-11, L89-12, L92-

13, and L95-14) between 1984 and 1999. Briefly, these

protocols consisted of remission induction therapy using

prednisolone or dexamethasone, vincristine and L-asparagi-

nase with or without cyclophosphamide and anthracyclines,

consolidation therapy, BFM (Berlin-Frankfurt-Munster)-

style reinduction therapy and maintenance therapy. The

duration of each protocol ranged from 1 year (L92-13) to 3½

years (L84-11). For prophylaxis of central nervous system

(CNS) leukemia, cranial irradiation or high dose methotrex-

ate (HD-MTX) with intrathecal injections were used

according to the criteria of each protocol. Table II shows

the number of patients who were treated with each protocol

and who received prophylactic cranial irradiation. Patient

age ranged from 1 to 15 years at diagnosis of ALL. All

treatments were performed with informed consent from the

patients’ guardians.

To evaluate the QOL of long-term survivors, information

about late complications was collected at annual follow-up

investigation. The median follow-up period for these patients

was 8 years and 8 months.

For statistical analysis, Chi-square tests were used

to analyze the relationships between MoS and clinical data.

Background. Long-term survivors of childhood acute lympho-blastic leukemia (ALL) sometimes suffer from adverse long-termsequelae. We analyzed the incidence, clinical course and prognosisof moyamoya syndrome (MoS) following childhood ALL. Procedure.A total of 1,846 ALL patients were treated with four consecutiveTCCSG ALL protocols (L84-11, L89-12, L92-13, and L95-14)between 1984 and 1999. We surveyed the MoS cases among thesepatients in the follow-up studies. Results. Six patients with MoS wereidentified: four boys and two girls whose ages ranged from 2 yearsand 1 month (abbreviated as ‘‘2y1m’’) to 14y 1m at diagnosis of ALL.None of the patients had central nervous system (CNS) leukemia. Allsix patients received prophylactic cranial irradiation with a dosage of

18 or 24 Gy. Although one patient died of brain infarction due toMoS, no leukemic relapse was observed in the group. Thecumulative incidence of MoS in our series was 0.46�0.02% at8 years. Among several clinical characteristics, use of cranialirradiation was the only factor that appeared to be significantlyrelated to the development of MoS. Conclusions. MoS occurs withincreased frequency in children treated for ALL, and might be asso-ciated with cranial irradiation. Prophylactic cranial irradiationshould be used cautiously in ALL patients who can be cured byother CNS-directed therapies. Pediatr Blood Cancer 2007;48:268–272. � 2006 Wiley-Liss, Inc.

Key words: childhood acute lymphoblastic leukemia; Moyamoya syndrome; prophylactic cranial irradiation; vasculopathy

� 2006 Wiley-Liss, Inc.DOI 10.1002/pbc.20837

——————Division of Hematology/Oncology, Saitama Children’s Medical

Center, Saitama, Japan

*Correspondence to: Akira Kikuchi, Division of Hematology/

Oncology, Saitama Children’s Medical Center, 2100 Magome

Iwatsuki-ku Saitama-shi, Saitama 339-8551, Japan.

E-mail: [email protected]

Received 25 September 2005; Accepted 14 February 2006

Page 2: Moyamoya syndrome following childhood acute lymphoblastic leukemia

RESULTS

We identified six MoS patients in the follow-up studies.

The clinical background of these six patients who developed

MoS following ALL is shown in Table III. Four Japanese

boys and two Japanese girls whose ages ranged from 2 years

and 1 month (abbreviated as ‘‘2y1m’’) to 14y 1m at diagnosis

of ALL were studied. Initial white blood cell (WBC) counts

were between 2,300 and 84,000/mm3. The immunopheno-

type was B precursor in all six patients. The treatment

regimen was L84-11 in four cases, L92-13 in one case, and

L95-14 in one case. Two patients were categorized as

standard risk and four as intermediate risk. No patient had

CNS leukemia at diagnosis or at any point during the clinical

course. All six patients experienced complete remission after

remission induction therapy and they received prophylactic

cranial irradiation with a dosage of 18 or 24 Gy. No leukemic

relapse was observed in these patients.

The age at diagnosis of MoS ranged from 3y2m to 20y 11m,

between 1y6m and 6y10m after diagnosis of ALL. The

interval between the onset of neurological symptoms and

diagnosis of MoS ranged from 1m to 3y9m. MoS was screened

by computed tomography (CT) (Fig. 1A), magnetic resonance

imaging (MRI) and MR angiography (MRA) and confirmed

by cerebral angiography (CAG) (Fig. 1B). In four of the

six patients, encephalo-duro-arterio-synangiosis (EDAS) or

encephalo-duro-arterio-myo-synangiosis (EDAMS) was per-

formed for MoS. These procedures are indirect revasculariza-

tion techniques for MoS in which vascularly rich tissues such

as dura mater(DM) and superficial temporal artery (STA) in

EDAS or temporal muscle in addition to DM and STA in

EDAMS are placed on the surface of the brain to induce

neovascularization to the ischemic part of the brain. All four

patients who received EDAS or EDAMS obtained improve-

ment of cerebral vascularity and neurological symptoms. In

one case (Case 6), a surgical procedure was not indicated

because the case was less severe. In another case (Case 3),

MoS was diagnosed by CAG after two transient ischemic

attacks (TIA). An EDAS operation was planned, but the

patient again suffered a severe ischemic attack and died due to

brain infarction resulting cerebral edema. The cumulative

incidence of MoS in our series was calculated as 0.46� 0.02%

at 8 years. We analyzed the relationship between MoS and

several clinical characteristics of the ALL patient (age, gender,

initial WBC, immunophenotype, treatment protocol and use

of cranial irradiation). Among these characteristics, use of

cranial irradiation was the only factor that was significantly

related to the development of MoS (6/1,105 vs. 0/741, Chi

square test, P¼ 0.045).

DISCUSSION

MoS is characterized by bilateral stenotic and occlusive

changes in the internal carotid arteries and their rich arterial

Pediatr Blood Cancer DOI 10.1002/pbc

TABLE I. Diagnostic Criteria for Moyamoya Disease

1. Cerebral angiography is indispensable for the diagnosis and should present the following findings as a minimum:

a. Stenosis or occlusion at the terminal portion of the internal carotid artery or at the proximal portion of the anterior or the middle cerebral

arteries.

b. Abnormal vascular networks demonstrated in the arterial phase in the vicinity of the occlusive or stenotic lesions.

c. These findings should be present bilaterally.

2. When magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) clearly demonstrated all the following findings,

conventional cerebral angiography is not mandatory:

a. Stenosis or occlusion at the terminal portion of the internal carotid artery or at the proximal portion of the anterior and the middle cerebral

arteries on MRA and an abnormal vascular network in the basal ganglia on MRA.

b. An abnormal vascular network can also be diagnosed when more than two apparent flow voids are seen by MRI in the basal ganglia on the

same side.

c. Findings a. and b. above are seen bilaterally.

3. Because the etiology of moyamoya disease is unknown, cerebrovascular disease associated with (and most likely caused by) the following

diseases should not be diagnosed as moyamoya disease: arteriosclerosis, autoimmune disease, meningitis, brain neoplasm, Down syndrome,

Recklinghausen’s disease, head trauma, irradiation to the head, or other known disease.

4. Instructive pathological findings are as follows:

a. Intimal thickening and consequent stenosis or occlusion of the lumen are observed in and around the terminal portion of the internal carotid

artery, usually on both sides. Lipid deposits occasionally are seen in the proliferating intima.

b. Arteries constituting the circle of Willis, such as the anterior and middle cerebral and posterior communicating arteries, often show stenosis

of various degrees or occlusion associated with fibrocellular thickening of the intima, a waving of the internal elastic lamina, and

attenuation of the media.

c. Numerous small vascular channels (perforators and anastomotic branches) are observed around the circle of Willis.

d. Reticular conglomerates of small vessels frequently seen in the pia mater.

TABLE II. The Numbers of Patients who Were Enrolled and whoReceived Prophylactic Cranial Irradiation in Each Protocol

Protocol

Patient

number

Cranial

irradiation

No cranial

irradiation

L84–11 484 484 0

L89–12 418 335 83

L92–13 347 152 195

L95–14 597 134 463

Total 1846 1105 741

Moyamoya Syndrome Following Childhood ALL 269

Page 3: Moyamoya syndrome following childhood acute lymphoblastic leukemia

collaterals at the base of the brain, and with known systemic

disease or a history of cranial insults. MoS associated with

hematological disease is mainly reported in hemoglobino-

pathy (sickle cell anemia) [10], coagulopathy such as protein

C deficiency [11] or protein S deficiency [12] and congenital

hemolytic anemia (hereditary spherocytosis) [13]. In

these disorders, obstruction of major arteries probably occurs

secondary to the increased cerebral blood flow caused

by anemia, hypercoagulability or poor microcirculation

resulting from spherical red blood cells. This leads to the

development of Moyamoya vessels as arterial collaterals. On

the other hand, MoS in malignant disease is mainly reported

in patients with brain tumor as a late effect of cranial

irradiation [14–16].

It is well-known that Moyamoya disease occurs pre-

dominantly in Asian people and in children, and its incidence

is estimated to be about 3.5/1,000,000 persons per year in

Japan [17]. About two thirds of patients are under the age of

15 and as about 15% of the total population of Japan is under

this age, the incidence of Moyamoya disease under the age of

15 in Japan is estimated to be about 1.5/100,000 person per

year. Our patients were almost exclusively Japanese children

and the incidence of six cases among 1,846 patients

with median follow-up period of nearly 9 years is apparently

20-fold higher than observed in the general pediatric

population. We suspected a causative relationship between

MoS and ALL or its treatment, and cranial irradiation

appeared to be the only factor significantly related to the

development of MoS. Recently, Kondoh et al. [18] reported

on MoS patient who had experienced ALL, and their case

also received cranial irradiation. They commented on the

possibility of co-existence of MoS and ALL. We have

extended their observations in a large series of patients with

Pediatr Blood Cancer DOI 10.1002/pbc

TABLEIII.

TheClinicalBackgroundoftheSix

Patients

whoDeveloped

MoSFollowingALL

Pat

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tN

um

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12

34

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m

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fm

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mm

3)

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00

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00

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enL

84

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4-1

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1L

84

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92

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HR

18

L9

5-1

4H

R1

8

Cra

nia

lir

rad

iati

on

do

se1

8G

y2

4G

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8G

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y

CN

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uk

emia

(�)

(�)

(�)

(�)

(�)

(�)

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20

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Fig. 1. Brain imaging of a patient with MoS (Case 2). A: Brain

computed tomography (CT) findings of Case 2. Bilateral strokes are

seen in the watershed distribution, indicating brain hypoperfusion.

B: Cerebral angiography (CAG) of the same patient. Stenotic portion of

internal carotid artery is indicated by black arrow and arterial collaterals

perfused by external carotid artery, so-called ‘‘Moyamoya vessels,’’ are

indicated by white arrows.

270 Kikuchi et al.

Page 4: Moyamoya syndrome following childhood acute lymphoblastic leukemia

ALL and found a significant correlation between these two

disorders, with a much higher incidence of MoS among ALL

patients than in the general pediatric population. Further-

more, we showed that MoS among ALL patients also

correlated with prophylactic cranial irradiation. Radiation-

induced MoS is mainly reported in brain tumor patients and

they usually receive high dose cranial irradiation (40–50 Gy)

for the treatment of tumors [14–16]. MoS after cranial

irradiation is a form of radiation-induced vasculopathy and

this is possibly why MoS is more than 20 times higher in our

ALL patients than in the general pediatric population.

Among our six MoS patients, two received prophylactic

cranial radiation at doses as low as 18 Gy: This is probably the

lowest dose of cranial irradiation among post-irradiation

MoS. Intrathecal injection and CNS-directed methotrexate

therapy were also performed on these patients and such

cranial insults might have influenced the development of

MoS. MoS associated with coagulation disorder has been

reported [12,13]. All of our patients received L-asparaginase

during the therapy and transient coagulopathy may also have

been present. However, our six MoS patients never

experienced clotting problems and we do not think L-

asparaginase related coagulopathy influenced the develop-

ment of MoS in our series.

The cumulative incidence of MoS in our series was

0.46� 0.02% at 8 years. However, we cannot deny the

possibility that there may be asymptomatic children with

this, or there may be children who had neurologic symptoms,

but were not evaluated for MoS. There is another possibility

that higher-than-expected incidence of MoS in our series

may be due to chance variation unrelated to cranial

irradiation. On the other hand, we might have missed

asymptomatic patients who developed MoS after treatment

because we did not perform brain MRI for all patients with

ALL at diagnosis or perform active surveillance for MoS in

the follow-up studies, so that underestimation might also

have occurred. However, as the observed incidence of

symptomatic MoS in our series was much higher than in

general population, we can conclude MoS occurs with

increased frequency in children treated for ALL, and might

be associated with cranial irradiation.

Cranial irradiation was first introduced by St. Jude

Childrens’ Research Hospital to prevent CNS leukemia. It

markedly reduced CNS leukemia and contributed to the

improvement of the prognosis of ALL. However, as the

prognosis of childhood ALL improved, the adverse effect of

prophylactic cranial irradiation became more evident and the

effort to limit the use of cranial irradiation in initial therapy

for ALL is now in progress [19–23]. Although cranial

irradiation contributed to the improvement of prognosis for

some patients in high-risk groups [24,25], unnecessary

prophylactic cranial irradiation should be avoided if possible

to prevent adverse late effects including MoS, especially in

Asian patients who might be more susceptible to Moyamoya

disease. It is noteworthy that in some cases there is a

relatively long time period between the onset of neurological

symptoms and diagnosis of MoS (more than 2 years in two

cases). Efficacy of vasoreconstructive surgery for radiation-

induced MoS has been reported sometimes [14–16,18]. As

an early surgical procedure can reduce the severity of post-

operative neurological sequelae, physicians should be alert to

neurological symptoms indicating MoS in ALL patients.

ACKNOWLEDGMENT

We thank Mrs. Kaori Itagaki for preparing and refining the

protocol data for acute lymphoblastic leukemia in the Tokyo

Children’s Cancer Study Group.

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