The somnolence syndrome in leukemic children following reduced daily dose fractions of cranial radiation

Under-recognized toxicities of cranial irradiation

Cranial irradiation of primary or metastatic lesions is frequent, historically with 3D-conformal radiation therapy and now with stereotactic radiosurgery and intensity modulation. Evolution of radiotherapy technique is concomitant to systemic treatment evolution permitting long time survival. Thus, physicians have to face underestimated toxicities on long-survivor patients and unknown toxicities from combination of cranial radiotherapy to new therapeutics as targeted therapies and immunotherapies. This article proposes to develop these toxicities, without being exhaustive, to allow a better apprehension of cranial irradiation in current context.

Comprehensive assessment of Somnolence Syndrome in patients undergoing radiation to the brain

AIM

The aim of this prospective study was to assess Somnolence Syndrome (SS) in patients undergoing radiation to the brain.

BACKGROUND

SS is one of the sequelae of radiation to the brain, which is observed within three months of radiation. This is a self-limiting condition and a failure to diagnose leads to unnecessary investigations. This study was undertaken to objectively and subjectively analyze the occurrence, clinical presentation and severity of SS.

MATERIALS AND METHODS

Thirty-three patients receiving radiation to the brain were included in the study. Visual Analog Scale (VAS) was used for subjective assessment and the Littman Somnolence Syndrome (LSS) scale was used for objective assessment of SS. Sleep Latency Test (SLT) was used to quantify SS.

RESULTS

VAS scores showed an initial fall until week 3, followed by a plateau and a sudden increase after week 10. LSS scale at week 11 and 12 showed that 13 patients (43.3%) had grade 2, 5 (16.7%) had grade 3; and 2 (6.7%) had grade 4 SS. SLT revealed a shift of predominant sleep pattern from NREM 1 to NREM 2 at 6 weeks after radiation with a p value of 0.0412.

CONCLUSIONS

An insight into SS, its features, frequency of occurrence and self limiting nature can prevent anxiety and unwarranted investigations in the immediate post radiation period.

Potential toxicities of prophylactic cranial irradiation

Prophylactic cranial irradiation (PCI) with total doses of 20-30 Gy reduces the incidence of brain metastasis (BM) and increases survival of patients with limited and extensive-disease small-cell lung cancer (SCLC) that showed any response to chemotherapy. PCI is currently not applied in non-small-cell lung cancer (NSCLC) since it has not proven to significantly improve OS rates in stage IIIA/B, although novel data suggest that subgroups that could benefit may exist. Here we briefly review potential toxicities of PCI which have to be considered before prescribing PCI. They are mostly difficult to delineate from pre-existing risk factors which include preceding chemotherapy, patient age, paraneoplasia, as well as smoking or atherosclerosis. On the long run, this will force radiation oncologists to evaluate each patient separately and to estimate the individual risk. Where PCI is then considered to be of benefit, novel concepts, such as intensity-modulated radiotherapy and/or neuroprotective drugs with potential to lower the rates of side effects will eventually be superior to conventional therapy. This in turn will lead to a re-evaluation whether benefits might then outweigh the (lowered) risks.

Treatment Options for Medulloblastoma and CNS Primitive Neuroectodermal Tumor (PNET)

OPINION STATEMENT

Medulloblastoma and central nervous system (CNS) primitive neuroectodermal tumor (PNET) are primary pediatric brain tumors that require multidisciplinary therapies. Although often treated similarly in clinical trials, they are biologically different diseases. Even within medulloblastomas and CNS PNETs, there are molecularly distinct subgroups with differing presentations and prognoses. Overall, prognosis is better for medulloblastomas. Specific treatments for these types of cancer are continuously evolving to maximize survival and minimize long-term sequelae of treatment. Patients should be treated on a clinical trial, if eligible, as they may gain benefit with minimal risk over current standard of care. The amount of residual disease after surgery better correlates with survival for medulloblastomas than for CNS PNETs. Maximal surgical resection of tumor should be done, only if additional permanent, neurologic deficits can be spared. Patients should have a staging work-up to assess the extent of disease. This includes postoperative magnetic resonance imaging (MRI) of the brain, MRI of the entire spine and lumbar cerebrospinal fluid (CSF) sampling for cytological examination, if deemed safe. Radiation therapy to the entire CNS axis is required, with a greater dose (boost) given to the region of the primary site or any bulky residual disease for older children. Adjuvant chemotherapy must be given even if no evidence of disease after radiation therapy exists, as the risk of relapse is substantial after radiation alone. Subsets of younger children with medulloblastoma, arbitrarily defined as those younger than 3 years of age in some studies and 4 or even 5 years in other studies, can be effectively treated with chemotherapy alone. Recent genomic studies have revealed further subtypes of disease than previously recognized. Clinical trials to exploit these biologic differences are required to assess potential efficacy of targeted agents. The treatment of medulloblastoma and CNS PNET can cause significant impairment in neurologic function. Evaluations by physical therapy, occupational therapy, speech therapy and neurocognitive assessments should be obtained, as needed. After therapy is completed, survivors need follow-up of endocrine function, surveillance scans and psychosocial support.

Somnolence syndrome in patients receiving radical radiotherapy for primary brain tumours: a prospective study

BACKGROUND AND PURPOSE

To characterise the incidence, pattern and severity of post cranial radiotherapy somnolence and to identify factors predictive of frequency and severity.

MATERIALS AND METHODS

Seventy consecutive patients receiving radical cranial irradiation were prospectively assessed for somnolence at baseline, during and up to 10weeks following radiotherapy using five variables scored on a visual analogue scale (VAS) and the Littman scale. Fatigue was measured using the FACT-G score and quality of life using the EORTC QLQC30+3 with the brain tumour module questionnaire.

RESULTS

Ninety percent of patients experienced ⩾grade 1 somnolence (Littman score) and this correlated with VAS scores (r=0.456, p<0.001). The score increased from 3 to 12weeks (p<0.001) with a peak at the end of treatment and improvement 6weeks later. None of the patient, disease or treatment characteristics analysed were predictive for the development or the severity of somnolence.

CONCLUSIONS

The majority of patients experience some degree of somnolence following radical radiotherapy for primary brain tumour and this follows a clear pattern during and after treatment. While there are no clear predictors of severity, the pattern described allows for provision of information for patients and carers to minimise the distress the syndrome may cause.

Somnolence syndrome and fever in pediatric patients with cranial irradiation

BACKGROUND

During initial treatments, pediatric cancer patients are frequently hospitalized for fever, which may be due to neutropenia or a manifestation of the somnolence syndrome (SS) after cranial radiation therapy (CRT). This was a retrospective chart review of patients who received CRT for central nervous system prophylaxis or treatment in acute lymphoblastic leukemia or lymphoma.

OBSERVATIONS

Of 21 patients, 15 (71%) developed SS; 10 were hospitalized for fever. Comparing somnolent and nonsomnolent patients, there was no statistically significant difference in the admission absolute neutrophil count; radiation dose, fraction, or duration; and time between completion of CRT and first hospitalization.

CONCLUSIONS

In postradiation phase, patients with SS are more likely to get fever leading to hospital admission regardless of ANC.

Somnolence syndrome after focal radiation therapy to the pineal region: case report and review of the literature

Somnolence syndrome classically occurs in children after cranial irradiation for acute lymphocytic leukemia. Symptoms include somnolence, fever, nausea and vomiting, and headache. The authors report a 29 year-old female who developed symptoms compatible with the somnolence syndrome after completing radiation therapy for a benign meningioma near the pineal region. Five weeks after completing conformal radiation therapy (54 Gy), she developed profound fatigue, headaches, and 102-degree fevers. Physical examination and routine laboratory work were unrevealing. Imaging was not performed. Prednisone was prescribed and within 1 week her symptoms had largely resolved. This is the first report of the somnolence syndrome after focal radiation therapy. The possible etiology of the somnolence syndrome is discussed.

Standard and novel radiotherapeutic approaches to neoplastic meningitis

Neoplastic meningitis usually occurs late in the natural history of cancer. Adequate staging and assessment of the patient's overall reserves and prognosis are crucial in determining whether aggressive treatment is justified. Although radiotherapy remains the single most effective treatment, it is considered palliative for epithelial cancers and is generally directed to sites of bulky disease that obstruct the flow of cerebrospinal fluid or cause neurologic dysfunction. Such diseases as leukemia, medulloblastoma, and germinoma are exceptions that can be treated definitively with craniospinal irradiation. Innovations in conformal therapy may help to reduce the significant amount of myelosuppression associated with spinal irradiation. The main long-term toxicity associated with whole-brain irradiation (WBI) is dementia resulting from leukoencephalopathy, which may be exacerbated when WBI is given in combination with chemotherapy. A case report highlighting the use of radiotherapy for palliation in a patient with neoplastic meningitis is presented at the end of this article.

Acute effects of irradiation on cognition: changes in attention on a computerized continuous performance test during radiotherapy in pediatric patients with localized primary brain tumors

PURPOSE

To assess sustained attention, impulsivity, and reaction time during radiotherapy (RT) for pediatric patients with localized primary brain tumors.

METHODS AND MATERIALS

Thirty-nine patients (median age 12.3 years, range 5.9-22.9) with primary brain tumors were evaluated prospectively using the computerized Conners' continuous performance test (CPT) before and during conformal RT (CRT). The data were modeled to assess the longitudinal changes in the CPT scores and the effects of clinical variables on these changes during the first 50 days after the initiation of CRT.

RESULTS

The CPT scores exhibited an increasing trend for errors of omission (inattentiveness), decreasing trend for errors of commission (impulsivity), and slower reaction times. However, none of the changes were statistically significant. The overall index, which is an algorithm-based weighted sum of the CPT scores, remained within the range of normal throughout treatment. Older patients (age >12 years) were more attentive (p < 0.0005), less impulsive (p < 0.07), and had faster reaction times (p < 0.001) at baseline than the younger patients. The reaction time was significantly reduced during treatment for the older patients and lengthened significantly for the younger patients (p < 0.04). Patients with a shunted hydrocephalus (p < 0.02), seizure history (p < 0.0006), and residual tumor (p < 0.02) were significantly more impulsive. Nonshunted patients (p < 0.0001), those with more extensive resection (p < 0.0001), and patients with ependymoma (p < 0.006) had slower initial reaction times.

CONCLUSION

Children with brain tumors have problems with sustained attention and reaction time resulting from the tumor and therapeutic interventions before RT. The reaction time slowed during treatment for patients <12 years old. RT, as administered in the trial from which these data were derived, has limited acute effects on changes in the CPT scores measuring attention, impulsiveness, and reaction time.

Radiation somnolence syndrome

Although initially described 7 decades ago, somnolence syndrome remains a poorly understood subacute effect of cranial irradiation. Despite the relatively transient and benign nature of somnolence syndrome, its symptoms can be distressing for children and caregivers. Anticipatory guidance related to radiation-induced somnolence remains a critical nursing intervention. This article reviews what is known about somnolence syndrome, including its causes, symptoms, and management.

The distress associated with cranial irradiation: a comparison of patient and nurse perceptions

Distress associated with attendance at a radiotherapy treatment center for cranial radiotherapy was assessed in 10 consecutive patients using a method first employed by Munro et al. (1). This involved using a series of cards, each with a potential side effect of radiotherapy printed on it. The subjects were asked to highlight which side effects were a problem to them. The same method was used to determine the perceptions of nurses caring for patients receiving cranial radiotherapy, and the results were compared. This preliminary study suggests that the patient group found the physical side effects of their treatment most distressing, with "tiredness" and "hair loss" predominating. The nurse group had a tendency to overestimate the amount of side effects experienced by patients. They were able to choose quite successfully many of the more distressing side effects mentioned by the patient group. The study indicates the need for further research into the specific problems of patients undergoing cranial radiotherapy.

[Radiotherapy in leukemia excluding total body irradiation]

Radiation techniques and indications in leukemias have been described in detail, yet prophylactic cranial irradiation in acute leukemia still has few indications. Cerebrospinal and testicular irradiation are reserved for relapsing disease. Radiation usually results in rapid functional improvement when used in neurologic emergencies and symptomatic neurologic or gross tumors relapses. Nevertheless, the improvements recently obtained by systemic chemotherapy have resulted in the reduction in the use of irradiation, especially in children, where it was considered deleterious with neuropsychological sequellae. Splenic irradiation remains useful for symptomatic myeloproliferative syndrome.

Reduced incidence of the somnolence syndrome after prophylactic cranial irradiation in children with acute lymphoblastic leukemia

A prospective double blind randomized trial comparing two different dose schedules of continuous steroid coverage during prophylactic cranial radiotherapy (CRT) in leukemic children was conducted to find out the optimum dose to be prescribed to reduce the incidence of Somnolence Syndrome (SS). Between April 1994 and February 1996, 32 patients with acute lymphoblastic leukemia received CRT of 18 Gy in 10 fractions. Patients were randomized to receive oral dexamethasone of 2 or 4 mg/m2 during radiotherapy. The diagnosis of SS was made clinically based on symptoms of somnolence. All patients were followed for a minimum of 8 months. The overall incidence of SS was 40%. The development of SS was steroid dose dependent. In low dose steroid arm the incidence of SS was 64.3% (9/14), compared to 17.6% (3/17) in high dose arm with statistically significant difference (P = 0.008). The median time to development of SS was 4 weeks. The most common symptom of SS was drowsiness followed by anorexia, headache, nausea, vomiting, decreased activity, irritability, fever and ataxia, respectively. The duration of symptoms ranged from 2 to 14 days. The development of SS was not related to the presence of acute reactions, age at the time of CRT and sex. In all cases the symptoms subsided completely and spontaneously. Our results suggest that steroid coverage at a dose of 4 mg/m2 during CRT reduces the incidence of SS. However, a multicentric prospective randomized trial is needed to determine the role and the optimal dose of steroid.

Analysis of data over time: a difficult statistical issue

The aim of this paper was to review the literature on time-series analysis and describe its use within the context of a nursing research project. The author utilized the method to investigate the symptoms of somnolence and fatigue that patients experienced following cranial irradiation for cancer. The need for longitudinal research in all areas of health care is a current concern. This is especially true in clinical areas where small patient numbers and palliative settings make large quantitative studies difficult. There are few studies or texts that help the practising researcher to explore data analysis over time in a way that reflects the time-series nature of these data. This raises questions of how to analyse such data. The study indicated that symptoms following radiotherapy were different from that previously described in the literature. Time-series analysis indicated a cyclical pattern that gave valuable information for planning supportive services. This paper explores some of the issues of time-series analysis and illustrates the process of analysis, exploring the benefits and disadvantages of this approach for research.

Patients' experiences following cranial radiotherapy: a study of the somnolence syndrome

The aim of this study was to establish whether somnolence syndrome existed in adults by exploring their experiences after receiving cranial radiotherapy. Somnolence syndrome is described as excessive sleep, drowsiness, lethargy and anorexia and was found to occur in these patients. A description of the phenomenon was drawn from triangulation of the data. For 6 weeks following radiotherapy, the participants completed a diary consisting of two elements, a quantitative visual analogue scale and an open diary. This was followed by a qualitative semi-structured interview. Patients experienced sleepiness which they described as 'exhausted doing nothing' and that any activity was a 'struggle'. Some individuals described sensory changes, deafness and an increase in leg and arm weakness. These experiences presented a series of unexpected changes in their health which resulted in fear of treatment failure and disease recurrence. The study suggests that more information should be provided for patients on the side-effects that occur after radiotherapy has finished. Somnolence syndrome presented for the participants an experience which is not adequately described in previous literature. The nurse has an important role in providing information to prepare patients for their experience and more knowledge about this phenomenon is required for these patients to be informed adequately.

Reduced incidence of the somnolence syndrome in leukemic children with steroid coverage during prophylactic cranial radiation therapy. Results of a pilot study

Chemotherapeutic regimens for childhood acute lymphoblastic leukemia (ALL) include a remission induction period with high, daily doses of prednisone among other agents. A period of central nervous system (CNS) prophylaxis follows, during which steroids are often tapered entirely before cranial radiation (CRT) is completed or even initiated. The somnolence syndrome (SS) has been described 4 to 6 weeks after completion of CRT in up to 60% of the children with doses as low as 1800 cGy. A pilot study of continuous steroid coverage during CRT in childhood ALL was conducted. From July 1984 to July 1986, 38 children entered on Children's Cancer Study Group ALL protocols received CRT of 1800 cGy (180 cGy x 10). All patients received oral prednisone throughout the entire course of CRT at daily doses varying from 3.0 to 60.0 mg/m2. The overall incidence of the SS was 13% (five patients). The development of the syndrome was steroid dose-dependent: greater than or equal to 15 mg/m2/d (one of 32 patients), 3% incidence; less than 15 mg/m2 (four of six patients), 67% incidence. The presence of headache during CRT was also steroid dose-related: greater than or equal to 15 mg/m2, one of 32 patients; less than 15 mg/m2, six of six patients. Of the seven patients with headache during CRT, five developed the SS. The two patients (both of the less than 15 mg/m2 group) who did not develop the SS were the only cases treated with increased steroid doses at the onset of headache symptoms. Steroid coverage at a dose of greater than or equal to 15 mg/m2 during CRT appears to significantly reduce the incidence of acute radiation reactions and the SS. A prospective randomized study is planned to confirm these initial findings.