Neurologic, neuropsychologic, and computed cranial tomography scan abnormalities in 2- to 10-year survivors of small-cell lung cancer

[Prospective longitudinal study on the evolution of autobiographical memory in patients irradiated for benign skull base tumour]

PURPOSE

Cranial irradiation can lead to long-term neurological complications, in particular memory disorders. The aim of this prospective study is to evaluate the impact of irradiation of benign skull base tumours located near the hippocampi on autobiographical memory.

PATIENTS AND METHODS

From 2016 to 2019, patients with cavernous sinus meningioma or pituitary adenoma treated with normofractionated irradiation were included. Patients underwent full neuropsychological assessment at baseline, 1year and 2years post-treatment. Neuropsychological tests were converted to Z-Score for comparability.

RESULTS

Twelve of the 19 patients included had a complete neuropsychological evaluation at 2years and were analysed. On the "TEMPau" test, no significant difference in autobiographical memory was found at 2years, regardless of the period of autobiographical memory. The mean hippocampal dose had no impact on the variation in autobiographical memory. There was no significant cognitive impairment in the other domains assessed, such as attention, anterograde memory, working memory and executive functions. Autobiographical memory was independent of these other cognitive domains, which justifies its specific study.

CONCLUSION

Radiotherapy to the skull base for a benign pathology does not lead to significant cognitive impairment. Longer follow-up would be needed to confirm these results.

Prophylactic cranial irradiation (PCI), hippocampal avoidance (HA) whole brain radiotherapy (WBRT) and stereotactic radiosurgery (SRS) in small cell lung cancer (SCLC): Where do we stand?

Small cell lung cancer (SCLC) is an aggressive form of lung cancer associated with an increased risk of develping brain metastases (BM), which are a significant cause of morbidity and mortality. Prophylactic cranial irradiation (PCI) was first introduced in the 1970s with the aim of reducing BM incidence and improving survival and quality of life (QoL). Prospective clinical trials and meta-analyses have demonstrated its effectiveness in reducing BM incidence and improving survival, across all stages of the disease following response to induction chemotherapy. Despite its long history, "unknowns" surrounding PCI use still exist and there are particular subgroups of patients for which its use remains controversial. PCI is known to cause neurocognitive toxicity which can have a significant impact on a patient's QoL. Strategies to minimise this, including the use of hippocampal avoidance radiotherapy techniques, neuroprotective drugs and stereotactic radiosurgery in place of whole brain radiotherapy for the treatment of BM, are under evaluation. This review offers a summary of the key PCI trials published to date and the current treatment recommendations based on available evidence. It also discusses the key questions being addressed in ongoing clinical trials and highlights others where there is currently a knowledge gap and therefore where further data are urgently required.

Prophylactic cranial irradiation or MRI surveillance for extensive stage small cell lung cancer

The treatment paradigm for extensive stage small cell lung cancer (ES-SCLC) is evolving. Prophylactic cranial irradiation (PCI) has long been considered a component of standard treatment in patients with extensive stage disease who respond to chemotherapy. However, in the modern era of magnetic resonance imaging, the role of PCI has become an area of controversy following conflicting level I evidence. Due to conflicting data and toxicity concerns, the routine use of PCI has declined. Recent improvements in systemic disease control with the use of immunotherapy and reductions in the toxicity attributable to PCI with hippocampal avoidance and memantine have reignited the discussion. As such, we present here a narrative review of PCI with a focus on historical milestones, randomized data, risk mitigation and future directions.

Cognitive functioning following brain irradiation as part of cancer treatment: Characterizing better cognitive performance

OBJECTIVE

Although brain radiation therapy (RT) impacts cognitive function, little is known about the subset of survivors with minimal cognitive deficits. This study compares the characteristics of patients receiving brain irradiation as part of cancer treatment with minimal cognitive deficits to those with poorer cognitive functioning.

METHODS

Adults at least 6 months postbrain RT (N = 198) completed cognitive measures of attention, memory, and executive functions. Cognitive functioning was categorized into better- and poorer-performing groups, with better-performing survivors scoring no worse than 1.5 standard deviations below the published normative mean on all cognitive measures. Logistic regression was used to identify variables associated with better-performing group membership.

RESULTS

Approximately 25% of the sample met the criteria for the better-performing group. In unadjusted analyses, RT type (whole brain irradiation and partial brain irradiation), sedating medications, and fatigue were independently associated with cognition. Sociodemographic and other clinical characteristics were not significant. In adjusted analyses, only fatigue remained significantly associated with group membership (OR = 1.05, 95% CI = 1.01-1.09, P = .009).

CONCLUSIONS

There is a subgroup of survivors with minimal long-term cognitive deficits despite undergoing a full course of brain RT as part of cancer treatment. Lower fatigue had the strongest association with better cognitive performance. Interventions targeting cancer-related fatigue may help buffer the neurotoxic effects of brain RT.

Cognitive disability in adult patients with brain tumors

Cognitive dysfunction is common among patients with intracranial tumors. Most cognitive deficits are subtle, lack specificity, may mimic depression or other neurological disorders and may be recognized in retrospect by the physician. In certain cases, distinguishing between tumor recurrence and cognitive deficits that arise as a consequence of the treatment becomes challenging. Late treatment effects have also become an area of focus as the overall survival and prognosis of patients with brain tumors increases. New data has highlighted the importance of less toxic adjuvant therapies owing to their positive impact on prognosis and quality of life. Various experimental therapies and genetic influences on individual sensitivity towards injury are promising steps towards a better management strategy for cognitive dysfunction. In this literature review, we discuss cognitive dysfunction as a manifestation of intracranial tumors, treatment modalities such as radiotherapy, chemotherapy, surgery and their impact on cognition and patients' quality of life. We also discuss management options for cognitive dysfunction and emerging therapies.

Prophylactic Cranial Irradiation for Extensive Small-Cell Lung Cancer

Small-cell lung cancer (SCLC) has a high predilection for metastasizing to the brain after chemotherapy. This has been blamed on the blood-brain barrier, which prevents chemotherapy from penetrating into the brain, thus creating a sanctuary site. It has been estimated that up to three quarters of patients with SCLC will eventually develop brain metastases. This led investigators to administer prophylactic cranial irradiation (PCI) to decrease this risk. Several trials were performed in patients with SCLC after initial therapy (chemotherapy with or without thoracic radiotherapy) that compared the outcomes of PCI versus no PCI. Early trials generally found that PCI significantly decreased the risk of brain metastases but did not significantly improve survival. These trials were re-evaluated in two larger meta-analyses that included patients with either limited-stage SCLC or extensive-stage SCLC (ESCLC). Both meta-analyses reported that PCI significantly decreased brain metastases and improved survival in patients who had a complete response following initial therapy. These studies were performed before the advent of modern imaging with computed tomography or magnetic resonance imaging (MRI). There have been two modern trials of PCI versus no PCI in patients with ESCLC and both found that PCI decreases brain metastases. The first did not include brain MRI before registration and found that PCI improved survival, whereas the second study did include MRI before registration and at frequent intervals thereafter. That trial found that PCI did not confer a survival advantage. This review will examine the evidence and provide recommendations regarding the role of PCI for patients with ESCLC.

Controversies in small cell carcinoma of the head and neck: Prophylactic cranial irradiation (PCI) after primary complete initial remission

Small cell carcinoma of head and neck region (SmCCHN) represents a rare entity and its management remains a significant clinical challenge. Complete initial response to primary therapy poses a difficult and controversial scenario for radiation oncologists. Prophylactic cranial irradiation (PCI) has long been established in the management of small cell lung cancer; however, its role in SmCCHN is still called into question. The rationale behind PCI lies in the eradication of possible micro-metastatic brain disease, which is often documented in this type of cancer. No randomized trials on this topic are available. This review, based on 20 retrospective studies, addresses the controversies in the use of PCI in SmCCHN management.

Donepezil for Irradiated Brain Tumor Survivors: A Phase III Randomized Placebo-Controlled Clinical Trial

PURPOSE

Neurotoxic effects of brain irradiation include cognitive impairment in 50% to 90% of patients. Prior studies have suggested that donepezil, a neurotransmitter modulator, may improve cognitive function.

PATIENTS AND METHODS

A total of 198 adult brain tumor survivors ≥ 6 months after partial- or whole-brain irradiation were randomly assigned to receive a single daily dose (5 mg for 6 weeks, 10 mg for 18 weeks) of donepezil or placebo. A cognitive test battery assessing memory, attention, language, visuomotor, verbal fluency, and executive functions was administered before random assignment and at 12 and 24 weeks. A cognitive composite score (primary outcome) and individual cognitive domains were evaluated.

RESULTS

Of this mostly middle-age, married, non-Hispanic white sample, 66% had primary brain tumors, 27% had brain metastases, and 8% underwent prophylactic cranial irradiation. After 24 weeks of treatment, the composite scores did not differ significantly between groups (P = .48); however, significant differences favoring donepezil were observed for memory (recognition, P = .027; discrimination, P = .007) and motor speed and dexterity (P = .016). Significant interactions between pretreatment cognitive function and treatment were found for cognitive composite (P = .01), immediate recall (P = .05), delayed recall (P = .004), attention (P = .01), visuomotor skills (P = .02), and motor speed and dexterity (P < .001), with the benefits of donepezil greater for those who were more cognitively impaired before study treatment.

CONCLUSION

Treatment with donepezil did not significantly improve the overall composite score, but it did result in modest improvements in several cognitive functions, especially among patients with greater pretreatment impairments.

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.

Prophylactic cranial irradiation in elderly patients with small cell lung cancer: findings from a North Central Cancer Treatment Group pooled analysis

OBJECTIVES

To examine the efficacy of prophylactic cranial irradiation (PCI) in elderly patients with small cell lung cancer (SCLC) (≥70 years of age) from a pooled analysis of four prospective trials.

MATERIALS & METHODS

One hundred fifty-five patients with SCLC (limited stage, LSCLC, and extensive stage, ESCLC) participated in four phase II or III trials. Ninety-one patients received PCI (30 Gy/15 or 25 Gy/10) and 64 patients did not receive PCI. Survival was compared in a landmark analysis that included only patients who had stable disease or better in response to primary therapy.

RESULTS

Patients who received PCI had better survival than patients who did not receive PCI (median survival 12.0 months vs. 7.6 months, 3-year overall survival 13.2% vs. 3.1%, HR = 0.53 [95% CI 0.36-0.78], p = 0.001). On multivariate analysis of the entire cohort, the only factor that remained significant for survival was stage (ESCLC vs. LSCLC, p = 0.0072). In contrast, the multivariate analysis of patients who had ESCLC revealed that PCI was the sole factor associated with a survival advantage (HR = 0.47 [95% CI 0.24-0.93], p = 0.03). Grade 3 or higher adverse events (AEs) were significantly greater in patients who received PCI (71.4% vs. 47.5%, p = 0.0031), with non-neuro and non-heme being the specific AE categories most strongly correlated with PCI delivery.

CONCLUSIONS

PCI was associated with a significant improvement in survival for our entire elderly SCLC patient cohort on univariate analysis. Multivariate analysis suggested that the survival advantage remained significant in patients with ESCLC. PCI was also associated with a modest increase in grade 3 or higher AEs.

Neurocognitive assessment following whole brain radiation therapy and radiosurgery for patients with cerebral metastases

The treatment of metastatic brain lesions remains a central challenge in oncology. Because most chemotherapeutic agents do not effectively cross the blood-brain barrier, it is widely accepted that radiation remains the primary modality of treatment. The mode by which radiation should be delivered has, however, become a source of intense controversy in recent years. The controversy involves whether patients with a limited number of brain metastases should undergo whole brain radiation therapy (WBRT) or stereotactic radiosurgery (SRS) delivered only to the radiographically visible tumours. Survival is comparable for patients treated with either modality. Instead, the controversy involves the neurocognitive function (NCF) of radiating cerebrum that appeared radiographically normal relative to effects of the growth from micro-metastatic foci. A fundamental question in this debate involves quantifying the effect of WBRT in patients with cerebral metastasis. To disentangle the effects of WBRT on neurocognition from the effects inherent to the underlying disease, we analysed the results from randomised controlled studies of prophylactic cranial irradiation in oncology patients as well as studies where patients with limited cerebral metastasis were randomised to SRS versus SRS+WBRT. In aggregate, these results suggest deleterious effects of WBRT in select neurocognitive domains. However, there are insufficient data to resolve the controversy of upfront WBRT versus SRS in the management of patients with limited cerebral metastases.

Treatment of small cell lung cancer: Diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines

BACKGROUND

Small cell lung cancer (SCLC) is a lethal disease for which there have been only small advances in diagnosis and treatment in the past decade. Our goal was to revise the evidence-based guidelines on staging and best available treatment options.

METHODS

A comprehensive literature search covering 2004 to 2011 was conducted in MEDLINE, Embase, and five Cochrane databases using SCLC terms. This was cross-checked with the authors' own literature searches and knowledge of the literature. Results were limited to research in humans and articles written in English.

RESULTS

The staging classification should include both the old Veterans Administration staging classification of limited stage (LS) and extensive stage (ES), as well as the new seventh edition American Joint Committee on Cancer/International Union Against Cancer staging by TNM. The use of PET scanning is likely to improve the accuracy of staging. Surgery is indicated for carefully selected stage I SCLC. LS disease should be treated with concurrent chemoradiotherapy in patients with good performance status. Thoracic radiotherapy should be administered early in the course of treatment, preferably beginning with cycle 1 or 2 of chemotherapy. Chemotherapy should consist of four cycles of a platinum agent and etoposide. ES disease should be treated primarily with chemotherapy consisting of a platinum agent plus etoposide or irinotecan. Prophylactic cranial irradiation prolongs survival in those individuals with both LS and ES disease who achieve a complete or partial response to initial therapy. To date, no molecularly targeted therapy agent has demonstrated proven efficacy against SCLC.

CONCLUSION

Evidence-based guidelines are provided for the staging and treatment of SCLC. LS-SCLC is treated with curative intent with 20% to 25% 5-year survival. ES-SCLC is initially responsive to standard treatment, but almost always relapses, with virtually no patients surviving for 5 years. Targeted therapies have no proven efficacy against SCLC.

Prophylactic cranial irradiation in small-cell lung cancer: findings from a North Central Cancer Treatment Group Pooled Analysis

BACKGROUND

This pooled analysis evaluated the outcomes of prophylactic cranial irradiation (PCI) in 739 small-cell lung cancer (SCLC patients with stable disease (SD) or better following chemotherapy ± thoracic radiation therapy (TRT) to examine the potential advantage of PCI in a wider spectrum of patients than generally participate in PCI trials.

PATIENTS AND METHODS

Three hundred eighteen patients with extensive SCLC (ESCLC) and 421 patients with limited SCLC (LSCLC) participated in four phase II or III trials. Four hundred fifty-nine patients received PCI (30 Gy/15 or 25 Gy/10) and 280 did not. Survival and adverse events (AEs) were compared.

RESULTS

PCI patients survived significantly longer than non-PCI patients {hazard ratio [HR] = 0.61 [95% confidence interval (CI): 0.52-0.72]; P < 0.0001}. The 1- and 3-year survival rates were 56% and 18% for PCI patients versus 32% and 5% for non-PCI patients. PCI was still significant after adjusting for age, performance status, gender, stage, complete response, and number of metastatic sites (HR = 0.82, P = 0.04). PCI patients had significantly more grade 3+ AEs (64%) compared with non-PCI patients (50%) (P = 0.0004). AEs associated with PCI included alopecia and lethargy. Dose fractionation could be compared only for LSCLC patients and 25 Gy/10 was associated with significantly better survival compared with 30 Gy/15 (HR = 0.67, P = 0.018).

CONCLUSIONS

PCI was associated with a significant survival benefit for both ESCLC and LSCLC patients who had SD or a better response to chemotherapy ± TRT. Dose fractionation appears important. PCI was associated with an increase in overall and specific grade 3+ AE rates.

Phase II study of Ginkgo biloba in irradiated brain tumor patients: effect on cognitive function, quality of life, and mood

Ginkgo biloba has been reported to improve cognitive function in older adults and patients with Alzheimer's disease and multi-infarct dementia. We conducted an open-label phase II study of this botanical product in symptomatic irradiated brain tumor survivors. Eligibility criteria included: life expectancy ≥30 weeks, partial or whole brain radiation ≥6 months before enrollment, no imaging evidence of tumor progression in previous 3 months, or stable or decreasing steroid dose, and no brain tumor treatment planned while on study. The Ginkgo biloba dose was 120 mg/day (40 mg t.i.d.) for 24 weeks followed by a 6-week washout period. Assessments performed at baseline, 12, 24 (end of treatment), and 30 weeks (end of washout) included KPS, Functional Assessment of Cancer Therapy-Brain (FACT-Br), Profile of Mood States, Mini-Mental Status Exam, Trail Making Test Parts A (TMT-A) and B (TMT-B), Digit Span Test, Modified Rey Osterrieth Complex Figure (ROCF), California Verbal Learning Test Part II, and the F-A-S Test.

RESULTS

Of the 34 patients enrolled on study, 23 (68 %) completed 12 weeks of treatment and 19 (56 %) completed 24 weeks of treatment. There were significant improvements at 24 weeks in: executive function (TMT-B) (p = 0.007), attention/concentration (TMT-A) (p = 0.002), and non-verbal memory (ROCF-immediate/delayed recall) (p = 0.001/0.002), mood (p = 0.002), FACT-Br subscale (p = 0.001), and the FACT physical subscale (p = 0.003).

CONCLUSIONS

Some improvement in quality of life and cognitive function were noted with Ginkgo biloba. However, treatment with Ginkgo biloba was associated with a high dropout rate.

Treatment of brain metastasis from lung cancer

Brain metastases are not only the most common intracranial neoplasm in adults but also very prevalent in patients with lung cancer. Patients have been grouped into different classes based on the presence of prognostic factors such as control of the primary tumor, functional performance status, age, and number of brain metastases. Patients with good prognosis may benefit from more aggressive treatment because of the potential for prolonged survival for some of them. In this review, we will comprehensively discuss the therapeutic options for treating brain metastases, which arise mostly from a lung cancer primary. In particular, we will focus on the patient selection for combined modality treatment of brain metastases, such as surgical resection or stereotactic radiosurgery (SRS) combined with whole brain irradiation; the use of radiosensitizers; and the neurocognitive deficits after whole brain irradiation with or without SRS. The benefit of prophylactic cranial irradiation (PCI) and its potentially associated neuro-toxicity for both small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC) are also discussed, along with the combined treatment of intrathoracic primary disease and solitary brain metastasis. The roles of SRS to the surgical bed, fractionated stereotactic radiotherapy, WBRT with an integrated boost to the gross brain metastases, as well as combining WBRT with epidermal growth factor receptor (EGFR) inhibitors, are explored as well.

Prophylactic cranial irradiation in locally advanced non-small cell lung cancer: outcome of recursive partitioning analysis group 1 patients

BACKGROUND

Prophylactic cranial irradiation (PCI) has been demonstrated to reduce or delay the incidence of brain metastases (BM) in locally advanced non-small cell lung carcinoma (LA-NSCLC) patients with various prognostic groups. With this current cohort we planned to evaluate the potential usefulness of prophylactic cranial irradiation (PCI) specifically in recursive partitioning analysis (RPA) Group 1, which is the most favorable group of LA-NSCLC patients.

METHODS

Between March 2007 and February 2008, 62 patients in RPA group 1 were treated with sequential chemoradiotherapy and PCI for stage IIIB NSCLC. The induction chemotherapy consisted of 3 courses of cisplatin (80 mg/m2) and docetaxel (80 mg/m2); each course was given every 21 days. Thoracic radiotherapy (TRT) was given at a dose of 60 Gy using 3-D conformal planning. All patients received a total dose of 30 Gy PCI (2 Gy/fr, 5 days a week), beginning on the first day of the TRT. Then, all patients received 3 further courses of the same chemotherapy protocol.

RESULTS

Six (9.7%) patients developed brain metastases during their clinical course. Only one (2%) patient developed brain metastasis as the site of first treatment failure. Median brain metastasis-free survival, overall survival, and progression free survival were 16.6, 16.7, and 13.0 months, respectively. By univariate analysis, rates of BM were significantly higher in patients younger than 60 years of age (p = 0.03). Multivariate analysis showed no significant difference in BM-free survival according to gender, age, histology, and initial T- and N-stage.

CONCLUSION

The current finding of almost equal bone metastasis free survival and overall survival in patients with LA-NSCLC in RPA group 1 suggests a longer survival for patients who receive PCI, and thereby have a reduced risk of BM.

Hippocampal neuron number is unchanged 1 year after fractionated whole-brain irradiation at middle age

PURPOSE

To determine whether hippocampal neurons are lost 12 months after middle-aged rats received a fractionated course of whole-brain irradiation (WBI) that is expected to be biologically equivalent to the regimens used clinically in the treatment of brain tumors.

METHODS AND MATERIALS

Twelve-month-old Fischer 344 X Brown Norway male rats were divided into WBI and control (CON) groups (n = 6 per group). Anesthetized WBI rats received 45 Gy of (137)Cs gamma rays delivered as 9 5-Gy fractions twice per week for 4.5 weeks. Control rats were anesthetized but not irradiated. Twelve months after WBI completion, all rats were anesthetized and perfused with paraformaldehyde, and hippocampal sections were immunostained with the neuron-specific antibody NeuN. Using unbiased stereology, total neuron number and the volume of the neuronal and neuropil layers were determined in the dentate gyrus, CA3, and CA1 subregions of hippocampus.

RESULTS

No differences in tissue integrity or neuron distribution were observed between the WBI and CON groups. Moreover, quantitative analysis demonstrated that neither total neuron number nor the volume of neuronal or neuropil layers differed between the two groups for any subregion.

CONCLUSIONS

Impairment on a hippocampal-dependent learning and memory test occurs 1 year after fractionated WBI at middle age. The same WBI regimen, however, does not lead to a loss of neurons or a reduction in the volume of hippocampus.

Incidence of brain atrophy and decline in mini-mental state examination score after whole-brain radiotherapy in patients with brain metastases: a prospective study

PURPOSE

To determine the incidence of brain atrophy and dementia after whole-brain radiotherapy (WBRT) in patients with brain metastases not undergoing surgery.

METHODS AND MATERIALS

Eligible patients underwent WBRT to 40 Gy in 20 fractions with or without a 10-Gy boost. Brain magnetic resonance imaging or computed tomography and Mini-Mental State Examination (MMSE) were performed before and soon after radiotherapy, every 3 months for 18 months, and every 6 months thereafter. Brain atrophy was evaluated by change in cerebrospinal fluid-cranial ratio (CCR), and the atrophy index was defined as postradiation CCR divided by preradiation CCR.

RESULTS

Of 101 patients (median age, 62 years) entering the study, 92 completed WBRT, and 45, 25, and 10 patients were assessable at 6, 12, and 18 months, respectively. Mean atrophy index was 1.24 +/- 0.39 (SD) at 6 months and 1.32 +/- 0.40 at 12 months, and 18% and 28% of the patients had an increase in the atrophy index by 30% or greater, respectively. No apparent decrease in mean MMSE score was observed after WBRT. Individually, MMSE scores decreased by four or more points in 11% at 6 months, 12% at 12 months, and 0% at 18 months. However, about half the decrease in MMSE scores was associated with a decrease in performance status caused by systemic disease progression.

CONCLUSIONS

Brain atrophy developed in up to 30% of patients, but it was not necessarily accompanied by MMSE score decrease. Dementia after WBRT unaccompanied by tumor recurrence was infrequent.

Boost radiosurgery for treatment of brain metastases after surgical resections

BACKGROUND

We evaluated results of resection surgery followed by boost radiosurgery for the treatment of brain metastases.

METHODS

We treated 21 patients (13 male, 8 female) with surgical resection (subtotal or total) followed by boost radiosurgery. The mean patient age was 61 years (range, 41-80 years); supratentorial lesions were treated in 12 patients, and posterior fossa lesions were treated in 9 patients. The most common primary cancers were lung (24%) and colon (24%). Fifty-three percent of patients had brain metastases only, whereas 47% had extracranial metastases. The radiosurgery dose plan was designed to radiate the operative cavity; the mean treatment volume (50% isodose) was 10.7 mL (range, 3.4-23.3 mL), and the mean marginal dose was 17 Gy (range, 13-20 Gy).

RESULTS

Local control was achieved in 16 (76%) patients. However, new intracranial lesions developed in 10 patients, and meningeal carcinomatosis occurred in 5 patients. Local tumor recurrence occurred more often for patients treated with lower radiotherapy doses (<18 vs > or =18 Gy, P = .03), and meningeal carcinomatosis occurred more often in patients with posterior fossa lesions (P = 0.05). Gamma knife radiosurgery was performed in 13 patients, and whole-brain radiation was performed in 2 patients. No patients experienced symptomatic radiation injury, and the median survival time was 20 months.

CONCLUSIONS

Although boost radiosurgery is less invasive and reduces morbidity, the radiosurgical dose must be higher than 18 Gy for the treatment to be most effective. Treatment of lesions of the posterior fossa must be considered carefully because of the higher frequency of meningeal carcinomatosis. Also, we recommend that the surgeons who operate on the metastatic tumors must try to decrease the resected cavity volume and to prevent cerebrospinal fluid dissemination at the operation for posterior fossa lesions.

Prophylactic cranial irradiation in operable stage IIIA non small-cell lung cancer treated with neoadjuvant chemoradiotherapy: results from a German multicenter randomized trial

PURPOSE

To investigate the role of prophylactic cranial irradiation (PCI) within a trimodality protocol (chemotherapy, chemoradiotherapy, surgery) for patients with operable stage IIIA non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

After mediastinoscopic staging, patients with operable stage IIIA NSCLC were enrolled to a German multicenter trial and randomly assigned to receive either primary resection followed by adjuvant thoracic radiation therapy (50 to 60 Gy; arm A) or preoperative chemotherapy (cisplatin/etoposide [PE]; three cycles) followed by concurrent chemoradiotherapy (PE plus 45 Gy; 1.5 Gy twice per day) and definitive surgery (arm B), respectively. Patients in arm B were scheduled to receive PCI (30 Gy; 2 Gy daily fractions).

RESULTS

One hundred twelve patients were randomly assigned between November 1994 and July 2001. One hundred six patients were eligible (arm A: 51, arm B: 55), 90 males and 16 females, 50 with squamous cell, 16 with large cell, five with adenosquamous, and 35 with adenocarcenoma (median age, 57 years; range, 37 to 71 years). Forty-three patients received PCI as scheduled in arm B. Eleven long-term survivors (arm A: four; arm B: seven) underwent a comprehensive neuropsychological examination. PCI significantly reduced the probability of brain metastases as first site of failure (7.8% at 5 years v 34.7%; P = .02), the overall brain relapse rate was reduced comparably (9.1% at 5 years v 27.2%; P = .04). A slightly reduced neurocognitive performance in comparison with the age-matched normal population was found for patients in both treatment groups. No significant difference between patients who were treated with or without PCI could be noted.

CONCLUSION

PCI is effective in preventing brain metastases following this aggressive trimodality approach. Neurocognitive late effects are not significantly different between patients treated with or without PCI.

Irradiation prophylactique cérébrale dans les cancers bronchopulmonaires non à petites cellules

Prophylactic cranial irradiation (PCI) has become part of the standard treatment in patients with small cell lung cancer (SCLC) in complete remission. Not only does it decrease the risk of brain recurrence by almost 50%, it has a significant positive effect on survival (5.4 percent increase at 3 years). As the prognosis of patients with locally advanced non-small cell lung cancer (NSCLC) has improved with combined modality treatment, brain metastases have also become an important cause of failure (10 to 30%, approaching 50% in certain studies as in SCLC). Survival after treatment of brain metastases is poor and impact on quality of life of patients is important. As in SCLC, 4 randomised evaluating PCI in NSCLC have been carried out in the seventies and early eighties. If 3 out of 4 trials have shown a significant decrease of brain metastases, none of them demonstrated any impact on survival. Thus PCI cannot be recommended as standard treatment in NSCLC, however new trials would be needed.

Managing the cognitive effects of brain tumor radiation therapy

Postoperative radiation therapy (RT), either alone or in combination with chemotherapy, is the mainstay of treatment for primary and/or metastatic brain tumors. The majority of patients with brain tumors will have significant symptoms of their disease and of RT that will have a negative impact on their quality of life and neurocognitive function. The symptoms of brain tumors depend on tumor location. Radiation-induced brain injury is a complex and dynamic process involving all cells in the brain, including endothelial and oligodendroglial cells, astrocytes, microglia, neurons, and neuronal stem cells. The symptoms of radiation-induced brain injury may be acute, subacute, or chronic, occurring hours, days, weeks, months, and even years after exposure to radiation, the pathogenesis of which is oxidative stress and inflammation. At present, there are no effective preventive approaches for radiation-induced brain injury. Rather, the management of radiation-induced fatigue, changes in mood, and cognitive dysfunction involves a multidisciplinary approach using pharmacologic, behavioral, and rehabilitative therapies. Given the prevalence of brain neoplasms and the high incidence of the radiation-induced symptom cluster and brain injury, clinical research to address these important clinical problems is critical.

Decision Analysis for Prophylactic Cranial Irradiation for Patients With Small-Cell Lung Cancer

Purpose

Prophylactic cranial irradiation (PCI) has been shown to provide survival benefit in patients with limited disease small-cell lung cancer (LD-SCLC) who have achieved complete response. However, PCI may also produce long-term neurotoxicity (NT). The benefits and risks of PCI in LD-SCLC are evaluated.

Methods

We developed a decision-analytic model to compare quality-adjusted life expectancy (QALE) in a cohort of SCLC patients who do or do not receive PCI by varying survival rates and the frequency and severity of PCI-related NT. Sensitivity analyses were applied to examine the robustness of the optimal decision.

Results

At current published survival rates (26% 5-year survival rate with PCI and 22% without PCI) and a low NT rate, PCI offered a benefit over no PCI (QALE = 4.31 and 3.70 for mild NT severity; QALE = 4.09 and 3.70 for substantial NT severity, respectively). With a moderate NT rate, PCI was still preferred. If the PCI survival rate increased to 40%, PCI outperformed no PCI with a mild NT severity. However, no PCI was preferred over PCI (QALE = 5.72 v 5.47) with substantial NT severity. Two-way sensitivity analyses showed that PCI was preferred for low NT rates, mild NT severity, and low long-term survival rates. Otherwise, no PCI was preferred.

Conclusion

The current data suggest PCI offers better QALE than no PCI in LD-SCLC patients who have achieved complete response. As the survival rate for SCLC patients continues to improve, NT rate and NT severity must be controlled to maintain a favorable benefit-risk ratio for recommending PCI.

Phase II study of donepezil in irradiated brain tumor patients: effect on cognitive function, mood, and quality of life

PURPOSE

A prospective, open-label phase II study was conducted to determine whether donepezil, a US Food and Drug Administration-approved reversible acetylcholinesterase inhibitor used to treat mild to moderate Alzheimer's type dementia, improved cognitive functioning, mood, and quality of life (QOL) in irradiated brain tumor patients.

PATIENTS AND METHODS

Thirty-four patients received donepezil 5 mg/d for 6 weeks, then 10 mg/d for 18 weeks, followed by a washout period of 6 weeks off drug. Outcomes were assessed at baseline, 12, 24 (end of treatment), and 30 weeks (end of wash-out). All tests were administered by a trained research nurse.

RESULTS

Of 35 patients who initiated the study, 24 patients (mean age, 45 years) remained on study for 24 weeks and completed all outcome assessments. All 24 patients had a primary brain tumor, mostly low-grade glioma. Scores significantly improved between baseline (pretreatment) and week 24 on measures of attention/concentration, verbal memory, and figural memory and a trend for verbal fluency (all P < .05). Confused mood also improved from baseline to 24 weeks (P = .004), with a trend for fatigue and anger (all P < .05). Health-related QOL improved significantly from baseline to 24 weeks, particularly, for brain specific concerns with a trend for improvement in emotional and social functioning (all P < .05).

CONCLUSION

Cognitive functioning, mood, and health-related QOL were significantly improved following a 24-week course of the acetylcholinesterase inhibitor donepezil. Toxicities were minimal. We are planning a double blinded, placebo-controlled, phase III trial of donepezil to confirm these favorable results.

Multimodality Therapy for Stage III Non–Small-Cell Lung Cancer

The treatment of stage III non–small-cell lung cancer has evolved over the last two decades, with combined-modality therapy the current standard of care. As a result, intermediate and long-term survival has improved for patients in this common stage category, compared to the poor outcomes achieved with the historical standard of once-daily radiation therapy alone. This review summarizes two decades of clinical research regarding bimodality and trimodality approaches for the heterogenous stage subsets within the stage III designation, discusses the rationale and status of prophylactic brain irradiation, and concludes with perspectives on progress and future directions. Chemotherapy plus radiotherapy given concurrently is the optimal treatment for the group of patients with advanced stage III disease. The potential role of a surgical resection following chemotherapy (with or without radiation) in this setting is still controversial. The only subsets for which trimodality treatments are clearly preferred include T4N0-1 disease and superior sulcus tumors. The other major stage III subgroup has a minimal disease burden with low tumor volume and/or microscopic N2 disease, thus technically could undergo a surgical resection upfront. Induction chemotherapy before surgery may yield a survival advantage, although the phase III trials in this area are not conclusive. Given the marked survival benefit from adjuvant chemotherapy after surgery in even earlier stages of non–small-cell lung cancer, the proper sequence of surgery and chemotherapy (before v after surgery) remains an important unresolved question in this subgroup. Furthermore, how to incorporate radiation therapy, as well as whether it should be given at all in this subset of patients, are other important issues actively under study in ongoing trials.

Progress in the therapy of small cell lung cancer

Small cell lung cancer (SCLC) accounts for approximately 14% of all cases of lung cancer. Combination chemotherapy is the most effective treatment modality for SCLC and recently, several new active drugs have emerged. Combinations of platinum agents with CPT-11 or gemcitabine have been successfully compared in phase III trials against the cisplatin/etoposide standard. Modest improvements in the outcome of patients with SCLC have been noted over the last two decades. Thoracic irradiation given concurrently with chemotherapy improves survival compared with sequential chemotherapy and radiation, but this approach is associated with more toxicity. Moreover, the optimal doses and fractionation of thoracic irradiation remain to be determined. Three-dimensional treatment planning is under investigation. Prophylactic cranial irradiation (PCI) has established a role in the management of patients who have achieved a complete response to the initial therapy. Novel molecular targeted therapies are among the strategies currently being investigated in SCLC.

A critical review of the clinical effects of therapeutic irradiation damage to the brain: the roots of controversy

We critically examined the damaging affects of therapeutic irradiation by comparing results from cross-disciplinary studies of early- and late-delayed radiotherapy effects. Focus is attained by concentrating on clinical treatment issues (volume of brain, dose, timing of effects, age, modality types, and stereotactic treatment techniques), rather than on methodological means or problems, which is necessary to understand the mechanisms and characteristics of radiotherapy-induced behavioral dysfunction including cognition. We make observations and hypotheses about the actual risks from radiotherapy that could be informative in the treatment decision process, and which may lessen the concerns of some patients and their families about the risks they take when receiving radiation. Conditions that predispose to radiation injury are reviewed: (1) higher doses even to part of the brain versus lower doses to the whole brain, (2) combined treatment modalities, (3) malignancy itself, (4) radiation early during postnatal brain development, and (5) late-delayed effects (more than 3 years posttreatment). Current neurocognitive frameworks for understanding cognitive change over time in children and adults are summarized, along with the literature on effects of brain tumors and treatment on depression. No studies have as yet identified candidate brain regions that are more sensitive to radiotherapy. Two studies have provided early, preliminary evidence for a specific vulnerability of visual attention/memory to the early stage of late radiation damage. Furthermore, radiation effects appear severe only in a minority of patients. Risk is related to direct and indirect effects of cancer type, concurrent clinical factors, and premorbid risk factors.

What is the effect of systemic anticancer treatment on cognitive function?

Treatment regimens for solid tumours have been extensively investigated for their physical toxic effects, but far less is known about the potential impairment of cognitive function by anticancer treatment regimens. Here, we review published studies that examined cognitive function in adult patients receiving systemic therapy for solid tumours. Our review suggests that patients can experience cognitive changes related to their treatment. However, several studies had methodological limitations, such as use of a limited sample size, lack of baseline assessment, and lack of control for potential confounding factors. Better designed clinical trials are required so that the difficulties patients face in terms of reduced cognitive function as a result of anticancer treatment can be fully elucidated. These trials should have sufficient statistical power and, importantly, should also be prospective.

Comparison of intensity-modulated radiotherapy with three-dimensional conformal radiation therapy planning for glioblastoma multiforme

This study was designed to assess the feasibility and potential benefit of using intensity-modulated radiotherapy (IMRT) planning for patients newly diagnosed with glioblastoma multiforme (GBM). Five consecutive patients with confirmed histopathologically GBM were entered into the study. These patients were planned and treated with 3-dimensional conformal radiation therapy (3DCRT) using our standard plan of 3 noncoplanar wedged fields. They were then replanned with the IMRT method that included a simultaneous boost to the gross tumor volume (GTV). The dose distributions and dose-volume histograms (DHVs) for the planning treatment volume (PTV), GTV, and the relevant critical structures, as obtained with 3DCRT and IMRT, respectively, were compared. In both the 3DCRT and IMRT plans, 59.4 Gy was delivered to the GTV plus a margin of 2.5 cm, with doses to critical structures below the tolerance threshold. However, with the simultaneous boost in IMRT, a higher tumor dose of approximately 70 Gy could be delivered to the GTV, while still maintaining the uninvolved brain at dose levels of the 3DCRT technique. In addition, our experience indicated that IMRT planning is less labor intensive and time consuming than 3DCRT planning. Our study shows that IMRT planning is feasible and efficient for radiotherapy of GBM. In particular, IMRT can deliver a simultaneous boost to the GTV while better sparing the normal brain and other critical structures.

Prophylactic cranial irradiation as a component of intensified initial treatment of locally advanced non-small cell lung cancer

Patients with locally advanced non-small cell lung cancer are threatened by the concurrent risks of local, regional and distant failure. By improving local and regional control with multimodality protocols, the brain becomes one of the major sites of relapse. PCI has a high potential to reduce the risk of brain metastases. Long-term toxicity is presently poorly defined and represents an important potential risk. The value of PCI as an adduct to present aggressive multimodality protocols and the optimal total dose with conventional fractionation will be investigated within clinical studies by two study groups in the future. As the best dose and fractionation still remains undefined, the integration of PCI into multimodality protocols.

Small cell lung cancer: current therapy and promising new regimens

In this review, we cover current therapy and promising new regimens and highlight areas where improvement is needed in the management of small cell lung cancer.

[The influence of age on radiation-induced cognitive deficit:experimental studies on brain irradiation of 30 gy in 10 sessions and 12 hours in the Wistar rat at 1 1/2, 4 and 18 months age]

The objective of this study was to determine the influence of age on the learning and memory dysfunction induced by cranial radiation in the male Wistar rat. Ninety-six 45-day-old, 70 4-month-old, and 78 18-month-old male rats were divided in two equal groups: (i) irradiated and (ii) control. A course of whole-brain radiation therapy (30 Gy in 10 fractions over 12 days) was administered to the irradiated group, while the control group received sham irradiation. Sequential behavioral studies including one and two-way avoidance tests were undertaken before and after the 7 months following radiation. The results suggest that radiation induced progressive and irreversible memory dysfunction in elderly (18-month-old) rats, but this effect was partial or almost reversible in the 4-month-old and 45-day-old rats, respectively. In return, the learning dysfunction was age non-dependent despite the fact that is occurs more rapidly in the young (45 days, 4 months) rats.

Patterns of failure after prophylactic cranial irradiation in small-cell lung cancer: analysis of 505 randomized patients

BACKGROUND

Prophylactic cranial irradiation (PCI) has a beneficial effect on overall survival in patients with small-cell lung cancer (SCLC) in complete remission as shown in a worldwide meta-analysis. The current analysis aimed to evaluate PCI effects on patterns of failure in this patient category.

PATIENTS AND METHODS

The Institut Gustave-Roussy coordinated two parallel randomized studies including a total of 511 patients with SCLC. Patients were randomly assigned to either PCI (24 Gy in eight fractions and 12 days) or no PCI. Patterns of failure were analyzed according to (i) total event rates and (ii) isolated first site of relapse using a competing risk approach.

RESULTS

Five hundred and five patients were analyzed. The 5-year cumulative rate of brain metastasis as an isolated first site of relapse was 37% in the control group and 20% in the PCI group (P < 0.001). The overall 5-year rates of brain metastasis were 59% and 43%, respectively [relative risk (RR) 0.50; P < 0.001]. The 5-year overall survival rates were 15% in the control group and 18% in the PCI group (RR 0.84; P = 0.06).

CONCLUSIONS

PCI decreased significantly the risk of brain metastasis. Other events were not influenced. The relative death risk reduction was of borderline significance. Results reported as isolated first cause of failure and subsequent competing events may explain why a major treatment effect on brain metastases rate has a rather moderate effect on survival.

Memory performance used to detect radiation effects on cognitive functioning

Although radiotherapy remains a necessary and frequently used treatmentfor brain tumors, uncertainty remains about the nature and severity of neurocognitive morbidity. We show that verbal-semantic memory (free recall of word list) is sensitive to damaging radiation effects in 20 patients with low-grade, supratentorial, primary brain tumors who received moderate doses of partial-brain irradiation. We previously reported that verbal-semantic memory is dissociated from visual memory (acquisition and recall) during the same phase ofradiation effects, indicating that memory is differentially affected by radiation. In this study, we provide evidence of the nature of the iatrogenic radiation effect on memory by testing collateral cognitive functions that might explain the specific memory impairment. We found that the verbal-semantic recall impairment was not associated with impairments in auditory attention, auditory processing speed, auditory-verbal working memory, or in the temporal coding or subjective organization of word-list recall. These findings focus damaging radiation effects on primary retrievalprocesses, rather than on earlier cognitive processes or executive processes affecting recall. Knowledge of the specific patterns of change in cognition would guide the differential diagnosis and rehabilitation of survivors of brain tumors whose conditions are complicated by tumors with multiple treatments.

The treatment of limited small cell lung cancer: a report of the progress made and future prospects

The improvements in the treatment of small cell lung cancer over the last 30 years have been realised by understanding that it is a systemic disease, but that areas of bulk and sanctuary require a complementary therapy. Despite successful strategies using combinations and thoracic radiotherapy, there remains uncertainty about what the best regimens are, their timing and their intensity. However, earlier concurrent therapy and rather brief intense chemotherapy and radiotherapy seem to produce the best results in moderately fit patients of all ages. How to select the fit patients and what to do about the less fit ones remains controversial and have economic consequences for governments and payers. Despite a meta-analysis demonstrating the success of prophylactic cranial irradiation (PCI), doubts linger about its safety, despite nothing more than anecdotal evidence from a previous era. The role of surgery continues to be explored, more in Europe than North America or Asia. Strategies for treatment of minimum residual disease seem a focus. New drugs, molecular targeted therapy, immunotherapy and other molecular therapies offer promise and theory, but there is little evidence about their place in the treatment protocols of today.

Cognitive dysfunction and histological findings in adult rats one year after whole brain irradiation

Cognitive dysfunction and histological changes in the brain were investigated following irradiation in 20 Fischer 344 rats aged 6 months treated with whole brain irradiation (WBR) (25 Gy/single dose), and compared with the same number of sham-irradiated rats as controls. Performance of the Morris water maze task and the passive avoidance task were examined one year after WBR. Finally, histological and immunohistochemical examinations using antibodies to myelin basic protein (MBP), glial fibrillary acidic protein (GFAP), and neurofilament (NF) were performed of the rat brains. The irradiated rats continued to gain weight 7 months after WBR whereas the control rats stopped gaining weight. Cognitive functions in both the water maze task and the passive avoidance task were lower in the irradiated rats than in the control rats. Brain damage consisting of demyelination only or with necrosis was found mainly in the body of the corpus callosum and the parietal white matter near the corpus callosum in the irradiated rats. Immunohistochemical examination of the brains without necrosis found MBP-positive fibers were markedly decreased in the affected areas by irradiation; NF-positive fibers were moderately decreased and irregularly dispersed in various shapes in the affected areas; and GFAP-positive fibers were increased, with gliosis in those areas. These findings are similar to those in clinically accelerated brain aging in conditions such as Alzheimer's disease, Binswanger's disease, and multiple sclerosis.