Survival following interstitial brachytherapy for recurrent malignant glioma

Iodine-125 brachytherapy for brain tumours--a review

Iodine-125 brachytherapy has been applied to brain tumours since 1979. Even though the physical and biological characteristics make these implants particularly attractive for minimal invasive treatment, the place for stereotactic brachytherapy is still poorly defined.An extensive review of the literature has been performed, especially concerning indications, results and complications. Iodine-125 seeds have been implanted in astrocytomas I-III, glioblastomas, metastases and several other tumour entities. Outcome data given in the literature are summarized. Complications are rare in carefully selected patients.All in all, for highly selected patients with newly diagnosed or recurrent primary or metastatic tumours, this method provides encouraging survival rates with relatively low complication rates and a good quality of life.

A Review of the Role of Re-Irradiation in Recurrent High-Grade Glioma (HGG)

Despite the use of more effective multimodal treatments in high-grade glioma (HGG), the outcome of patients affected by this disease is still dismal and recurrence is a very common event. Many therapeutic approaches, alone or combined (surgery, drugs, targeted agents, immunotherapy, radiotherapy, supportive therapy), are available in the clinical armamentarium so far. The attitude of physicians is increasingly interventionist, but recurrent HGG still remains a very difficult scenario to be treated. Radiotherapy with different re-irradiation techniques is increasingly proposed as a therapeutic option with interesting results, even though the resulting duration of response is usually quite short. Most lesions re-recur locally, with inadequate identification and targeting of viable tumor being the most important cause of failure. Prognosis is affected by many patient-, tumor-, and treatment-associated prognostic factors. Radiotherapy is delivered with many advanced modalities: 3D-CRT, intensity-modulated radiation therapy, stereotactic fractionated radiotherapy, radiosurgery, and brachitherapy with or without chemotherapy administration. In order to evaluate the feasibility and efficacy of re-irradiation in this setting, we reviewed the PubMed and MEDLINE databases restricting the search to original reports published from January 1990 to June 2011. The search resulted in a total of 155 reports: 78 of them covering 2,688 patients treated with different irradiation modalities overall fulfilled the entry criteria. Radiation therapy demonstrated to be an acceptable option in recurrent HGG with good response rates and acceptable toxicity.

Brachytherapy for brain tumors

Over the past several decades neurooncologists have attempted to find an adjuvant treatment that prolongs survival for patients with malignant brain tumors. Brachytherapy, radiotherapy delivered by placing radioactive sources directly into the tumor, was initially thought to be the solution to this problem. Initial single institution studies showed very promising results; however, this technique has failed to show a significant survival advantage in two randomized studies. Despite this, brachytherapy continues to be used in a number of centers throughout the world for the treatment of various types of brain tumors including low-grade gliomas, anaplastic astrocytomas, glioblastomas, meningiomas and metastases. This article reviews brachytherapy's rationale, radiobiology, complications, indications, and results from numerous studies that have focused on its application for brain tumors with emphasis on its application for glial tumors.

Brachytherapy of glioblastoma recurring in previously irradiated territory: predictive value of tumor volume

PURPOSE

To evaluate the impact of tumor volume on survival of patients reirradiated with (192)Ir for recurrent glioblastoma.

METHODS AND MATERIALS

Between 1993 and 1997, 42 patients with recurrent glioblastomas (29 males and 13 females, age 18-69 years, median age 49) were treated with (192)Ir implantation. Previous treatments included surgery, external beam radiotherapy, and chemotherapy. Maximum diameter of the recurrent tumor was 1.2-10.1 cm (median: 5.7 cm) and tumor volume was 1.6-122 cm(3) (median: 23 cm(3)). Karnofsky performance status score was 50-100 (median: 80). Brachytherapy dose was 40-60 Gy.

RESULTS

Probability of overall survival was 80% at 6 months, 48% at 1 year, and 11% at 2 years. Median survival was 50 weeks. Univariate analysis showed that both tumor volume (T < or T > or = 30 cm(3)) and Karnofsky performance status score were significant predictors of survival. Multivariate analysis showed that smaller tumor volumes were associated with a higher probability of survival (p < 0.001).

CONCLUSION

Tumor volume less than 30 cm(3) was associated with a higher probability of, and quality of, survival than larger lesions for patients reirradiated by brachytherapy for recurrent glioblastoma.

Post-partum retreatment with iridium-192 wire brachytherapy for meningioma recurring in pregnancy

We report the case history of a female patient who had received radical radiotherapy for a malignant meningioma at the age of 11 years. Thirteen years later, during her first pregnancy, she presented with a recurrence. The tumour was surgically debulked, but complications related to postoperative sepsis, the location of the tumour, and the extent of her previous treatment made the delivery of adjuvant radiotherapy problematic. The tumour bed was treated using an interstitial implant of 192Ir wires to a dose of 60 Gy in 100 hours. The patient remains well with no evidence of tumour recurrence or brain necrosis 2 years later. We discuss the role of female sex hormones in meningioma and the difficulties of radical retreatment of tumours in the central nervous system. The various techniques of brachytherapy in the brain are highlighted. The specific advantages of 192Ir in this patient are discussed.

Brain tumors in the older person

BACKGROUND

The incidence of brain tumors is increasing rapidly, particularly in the older population. Advances in molecular biology help to explain differences in biologic behavior and response to therapy of brain tumors in the elderly compared with younger patients. The number of elderly patients who desire and receive therapy for brain tumors and are included in clinical trials is increasing.

METHODS

This article reviews the literature on the epidemiology, clinical aspects, and therapy of brain tumors, with emphasis on the older patient population.

RESULTS

The increased incidence of brain tumors in the elderly is principally due to the increasing number of people who comprise the older population. Age and performance status are important independent prognostic indicators, together with tumor histology. Surgery, radiation therapy, and chemotherapy can benefit elderly patients with brain tumors with favorable histologies, tumor location, and good performance status. The response rates to available therapies are less favorable than in younger patients, and only a small number of elderly patients are enrolled in clinical studies addressing new treatment modalities.

CONCLUSIONS

Brain tumors in the elderly have specific characteristics that determine their biologic behavior and response to therapy. There is a need for clinical studies designed for treatment of brain tumors in older patients, and requirements for rehabilitation and support systems for the elderly need to be addressed.

The role of brachytherapy for palliation

The goal of palliative radiation is to alleviate symptoms in a short amount of time and maintain an optimal functional and quality-of-life level while minimizing toxicity and patient inconvenience. Despite advances in multimodality antineoplastic therapies, failure to control the tumor at its primary site frustratingly remains the predominant source of morbidity and mortality in many patients with cancer. Escalation of doses of radiation using external beam irradiation has been shown to improve local tumor control, but limits are imposed by the tolerance of normal surrounding structures. The highly conformal nature of brachytherapy enables the radiation oncologist to accomplish safe escalation of radiation doses to the tumor while minimizing doses to normal surrounding structures. Thus, by enhancing the potential for local control, brachytherapy used alone or as a supplement to external beam radiation therapy retains a significant and important role in achieving the goals of palliation. Proper patient selection, excellent technique, and adherence to implant rules will minimize the risk of complications. The advantages realized with the use of brachytherapy include good patient tolerance, short treatment time, and high rates of sustained palliation. This article reviews various aspects of palliative brachytherapy, including patient selection criteria, implant techniques, treatment planning, dose and fractionation schedules, results, and complications of treatment. Tumors of the head and neck, trachea and bronchi, esophagus, biliary tract, and brain, all in which local failure represents the predominant cause of morbidity and mortality, are highlighted.

Dual-isotope single-photon emission computerized tomography scanning in patients with glioblastoma multiforme: association with patient survival and histopathological characteristics of tumor after high-dose radiotherapy

OBJECT

The study was conducted to determine the association between dual-isotope single-photon emission computerized tomography (SPECT) scanning and histopathological findings of tumor recurrence and survival in patients treated with high-dose radiotherapy for glioblastoma multiforme.

METHODS

Studies in which SPECT with 201Tl and 99mTc-hexamethypropyleneamine oxime (HMPAO) were used were performed 1 day before reoperation in 47 patients with glioblastoma multiforme who had previously been treated by surgery and high-dose radiotherapy. Maximum uptake of 201Tl in the lesion was expressed as a ratio to that in the contralateral scalp, and uptake of 99mTc-HMPAO was expressed as a ratio to that in the cerebellar cortex. Patients were stratified into groups based on the maximum radioisotope uptake values in their tumor beds. The significance of differences in patient gender, histological characteristics of tissue at reoperation, and SPECT uptake group with respect to 1-year survival was elucidated by using the chi-square statistic. Comparisons of patient ages and time to tumor recurrence as functions of 1-year survival were made using the t-test. Survival data at 1 year were presented according to the Kaplan-Meier method, and the significance of potential differences was evaluated using the log-rank method. The effects of different variables (tumor type, time to recurrence, and SPECT grouping) on long-term survival were evaluated using Cox proportional models that controlled for age and gender. All patients in Group I (201Tl ratio < 2 and 99mTc-HMPAO ratio < 0.5) showed radiation changes in their biopsy specimens: they had an 83.3% 1-year survival rate. Group II patients (201Tl ratio < 2 and 99mTc-HMPAO ratio of > or = 0.5 or 201Tl ratio between 2 and 3.5 regardless of 99mTc-HMPAO ratio) had predominantly infiltrating tumor (66.6%); they had a 29.2% 1-year survival rate. Almost all of the patients in Group III (201Tl ratio > 3.5 and 99mTc-HMPAO ratio > or = 0.5) had solid tumor (88.2%) and they had a 6.7% 1-year survival rate. Histological data were associated with 1-year survival (p < 0.01): however, SPECT grouping was more closely associated with 1-year survival (p < 0.001) and was the only variable significantly associated with long-term survival (p < 0.005).

CONCLUSIONS

Dual-isotope SPECT data correlate with histopathological findings made at reoperation and with survival in patients with malignant gliomas after surgical and high-dose radiation therapy.

Interstitial brachytherapy for malignant brain tumors

For nearly 20 years, interstitial brachytherapy has been used as adjuvant treatment for malignant brain tumors in both prospective clinical trials and as part of standard therapy. Numerous publications analyzing the results of this treatment seem to indicate an improvement in median survival for highly selected patients. Some newly diagnosed glioblastoma multiforme, recurrent malignant glioma, brain metastases and possibly low grade gliomas seem to benefit. While Iodine-125 (I-125) remains the most popular radionuclide for brachytherapy, there is a recent move away from temporary high-activity implants to permanent low-activity implants. This review article will concentrate on the results from the University of California, San Francisco, as well as recent series published since 1990. In spite of the increased availability of radiosurgery, interstitial brachytherapy still has a place in the management of these difficult tumors.

Cognitive functioning and quality of life in malignant glioma patients: a review of the literature

The state of current research in the psychosocial and neurocognitive functioning of primary brain tumor patients, particularly those with gliomas, is reviewed. Specific instruments that have been used to evaluate psychosocial and neurocognitive functioning in this population are reviewed. Suggestions are made, based on the review, of the most appropriate psychosocial and neurocognitive instruments to implement in clinical research. Finally, research pertaining to psychosocial and neurocognitive interventions is reviewed and suggestions for further research are outlined. Few studies have adequately addressed the cognitive and psychosocial functioning of brain tumor patients and have focused primarily on relatively insensitive measures of outcome, including IQ scores, performance status, and neurologic examinations. The use of well-accepted, psychometrically sound quality of life instruments and more specific tests of cognitive functioning need to be included in clinical trials since most current treatments have a limited effect on the length of survival. Thus, the main rationale for selecting a given brain tumor therapy may ultimately be related to its profile of neurotoxic side-effects and impact on quality of life.

Interstitial brachytherapy procedures for brain tumors

Promising results have been obtained using brachytherapy in the treatment of brain tumors. Very low-dose rate brachytherapy (60-100 Gy given at 0.05-0.10 Gy/h) has been used for low-grade gliomas, resulting in 5- and 10-year survival probabilities of 85% and 83% for pilocytic astrocytomas and 61% and 51% for grade II astrocytomas. Only 2.6% of patients had symptomatic radiation necrosis. For faster-growing high-grade gliomas, temporary implants delivering about 60 Gy at 0.40-0.60 Gy/h are generally used. The largest series have reported median survival times of 12-13 months after brachytherapy for recurrent malignant gliomas and 18-19 months after diagnosis of primary glioblastomas treated with external beam radiotherapy and brachytherapy boost. A recent prospective, randomized trial demonstrated significantly improved survival for high-grade glioma patients who had brachytherapy boost. However, over 50% of patients who undergo brachytherapy for malignant gliomas require reoperation for tumor progression and/or radiation necrosis. Strategies are under development to improve local control without increasing radiation toxicity.

Computer planning of stereotactic iodine-125 seed brachytherapy for recurrent malignant gliomas

At St Thomas' Hospital, we have developed a computer program on a Titan graphics supercomputer to plan the stereotactic implantation of iodine-125 seeds for the palliative treatment of recurrent malignant gliomas. Use of the Gill-Thomas-Cosman relocatable frame allows planning and surgery to be carried out at different hospitals on different days. Stereotactic computed tomography (CT) and positron emission tomography (PET) scans are performed and the images transferred to the planning computer. The head, tumour and frame fiducials are outlined on the relevant images, and a three-dimensional model generated. Structures which could interfere with the surgery or radiotherapy, such as major vessels, shunt tubing etc., can also be outlined and included in the display. Catheter target and entry points are set using a three-dimensional cursor controlled by a set of dials attached to the computer. The program calculates and displays the radiation dose distribution within the target volume for various catheter and seed arrangements. The CT co-ordinates of the fiducial rods are used to convert catheter co-ordinates from CT space to frame space and to calculate the catheter insertion angles and depths. The surgically implanted catheters are after-loaded the next day and the seeds left in place for between 4 and 6 days, giving a nominal dose of 50 Gy to the edge of the target volume. 25 patients have been treated so far.