Permanent I Interstitial Radiation Therapy in the Treatment of Non-GBM High-Grade Gliomas

This study evaluates prognostic factors influencing survival outcomes for 50 patients with permanent¹²⁵ iodine-125 implants in the primary treatment of non-GBM high-grade gliomas. Stereotactic treatment planning aimed to encompass the contrast-enhancing rim of the tumor visualized by CT, with an initial dose rate of 0.05 Gy/hour with ¹²⁵I, delivering 100 Gy at 1 year and 103.68 Gy at infinity. Survival was evaluated using the Kaplan–Meier method for unvariate analysis and the Cox regressional method for multivariate analysis. In addition to the implant, 31 patients received external radiation therapy (5000 to 6000 cGy) before the implant; 10 patients were implanted without additional external beam radiation, and 9 patients underwent external radiation therapy before implant placement. With a mean follow-up of 40.76 months (range 3.47–87 months); 1–, 3–, and 5-year survival were 78.5% (± .05%), 58.7% (± .07%), and 56.2% (± .07%) respectively. Since 56.2% of the patients were alive at 5 years, median survival has not been reached yet. Second surgery was performed following the implant in 19 patients. Findings were tumor recurrence in 11 patients (22.5%), radiation necrosis in 7 patients (14.3%), and brain abcess in 1 patient (2%). Age, sex, tumor location, side of brain, tumor volume, Karnofsky, and neurological status were correlated with survival outcome. Favorable prognostic factors were age younger than 45 years, superficial tumor location, and preoperative Karnofsky greater than 70. Surgical treatment of patients with non-GBM high grade gliomas combined with external beam radiation and permanent ¹²⁵I implants represent a valuable alternative for the treatment of patients with malignant gliomas, allowing patients good quality of life and long survival.     

Stereotactic Radiosurgery for Human Glioma: Treatment Parameters and Outcome for Low vs. High Grade

Stereotactic radiosurgery (SRS) offers the precise, local delivery of radiation for the treatment of recurrent gliomas. We examined the comparative characteristics, treatments, and outcome in a population having with low– and high–grade gliomas. Between September 1991 and December 1995, 20 patients (13 males, 7 females) had SRS for low-grade [9 patients: World Health Organization (WHO) grade II] vs. high-grade (11 patients: 9 WHO grade IV and 2 WHO grade III) gliomas. The patients with low-grade gliomas were younger (mean age ± SE, 39.6 ± 5.4 years; range, 11.4–61.0 years) than those with high-grade gliomas (51.3 ± 13.9 years; range, 32.9–78.5 years) (P = 0.09). Tumor locations were similar in the two groups: lobar for 7 of 9 low-grade vs. 9 of 11 high-grade gliomas (P = NS) and diencephalic or cerebellar for the remainder. The initial surgical treatments were biopsy, subtotal resection, and total resection for three, three, and three patients with low-grade gliomas, vs. three, seven, and one patients with high-grade gliomas, respectively (P = NS). Except for three patients with low-grade gliomas, all patients had conventional postoperative fractionated external-beam radiotherapy. The doses were 5583 ± 342 vs. 5345 ± 261 cGy (P = NS) for low- vs. high-grade gliomas, respectively. Intervals from surgery and conventional radiation (if given) to progression and SRS tended to be longer for low-grade gliomas: 37.5 ± 9.5 vs. 30.6 ± 11.1 months (P = NS) for low- vs. high-grade gliomas, respectively. High-grade gliomas were larger. The diameters of the collimators that allowed enclosure of the enhancing tumor volume within the specified treatment isodoses were 22.4 ± 2.0 mm for low-grade vs. 29.8 ± 2.8 mm for high-grade gliomas (P = 0.02, ANOVA). SRS doses and isodose percentiles were similar, however, for the two groups: 1650 ± 191 cGy and 79 ± 4.0% vs. 1932 ± 182 cGy and75 ± 3.5% for low- vs. high-grade gliomas, respectively (P = NS, dose and isodose). All patients with high-grade gliomas were followed until death. The mean survival after SRS was 11.6 ± 1.5 months (42 ± 12 months after surgery). Five of nine patients with low-grade gliomas expired 31.6 ± 6.0 months after SRS (P < 0.001, Kaplan–Meier log rank) (74.0 ± 16.0 months after surgery). The four survivors have been followed for 8, 13, 35, and 38 months after SRS, respectively. Multivariate analysis shows that the category of histologic grade correlates significantly with survival after radiosurgery (P = 0.01). SRS may be an important therapeutic option for patients with recurrent gliomas, regardless of their grade.     

Brachytherapy of brain tumors.

Temporary implants of high-activity 125iodine sources have been used in the treatment of brain tumors since December 1979 at the University of California, San Francisco. For previously untreated patients who underwent external beam radiation therapy followed by implant boost, median survival from the date of diagnosis was 88 weeks for 34 patients with glioblastoma multiforme (GM) and 157 weeks for 29 patients with nonglioblastoma gliomas (NGM). For recurrent tumors treated with brachytherapy only, median survival from the date of the implant was 54 weeks for 45 patients with GM and 81 weeks for 50 patients with NGM. Finally, in 48 patients with recurrent tumors treated with combined hyperthermia and brachytherapy, median survival from the date of the implant was 46 weeks for 25 patients with GM and 44 weeks for 7 patients with metastases; 18-month survival was 65% for 16 patients with NGM. Brachytherapy appears to be a useful technique for the treatment of selected recurrent brain tumors and selected primary glioblastomas.     

Safety and efficacy of permanent iodine-125 seed implants and carmustine wafers in patients with recurrent glioblastoma multiforme

OBJECT: Effective treatment options are limited for patients with recurrent glioblastoma multiforme (GBM), and survival is usually <1 year. Novel treatment approaches are needed. Localized adjunct treatment with carmustine (BCNU) wafers or permanent, low-activity 125I seed implants has been shown to be effective for GBM. This study assessed the efficacy and safety of these therapies in combination following tumor resection. METHODS: Thirty-four patients with recurrent GBM were treated with maximal tumor resection followed by implantation of BCNU wafers and permanent 125I seeds into the tumor cavity. Patients were followed up with clinical evaluations and magnetic resonance imaging studies once every 3 months. Survival and progression-free survival (PFS) were evaluated. RESULTS: During follow-up, local disease progression was observed in 27 patients, and 23 of them died. The median survival period was 69 weeks, and the median PFS was 47 weeks. The 12-month survival and PFS rates were 66 and 32%, respectively. Baseline factors associated with prolonged survival included Karnofsky Performance Scale score>or=70, 125I seed activity>or=0.8 mCi/cm3 of tumor cavity, and age<60 years. Brain necrosis developed in 8 patients (24%) and was successfully treated with surgery or hyperbaric oxygen therapy. CONCLUSIONS: The use of adjunct therapy combining BCNU wafers and permanent 125I seeds resulted in survival that compares favorably with data from similar studies performed in patients with recurrent GBM. The incidence of brain necrosis appeared to be higher than that expected with either treatment alone, although the necrosis was manageable and did not affect survival. This novel approach warrants further investigation in recurrent and newly diagnosed GBM.     

Stereotactic interstitial radiotherapy for brain tumors

The narrow margin between tumor sensitivity and healthy brain sensitivity to radiation considerably limits conventional radiation therapy (teletherapy). Interstitial radiotherapy (brachytherapy) with iodine-125 permanent implants is effective for local tumor control. So far, interstitial radiotherapy using low activity permanent or temporary implants has been carried out in 179 patients with differentiated gliomas (132 cases) and other tumors-anaplastic gliomas and glioblastomas (16 cases), ependymomas and papillomas (4 cases) and a variety of other mostly extracerebral tumors (27 cases)-in functionally critical cortical or deep-seated location. Brachytherapy with I-125 implants is recommended for slowly proliferating, differentiated non-resectable tumors in functionally critical areas. It enables the surgeon to achieve a radiosurgical tumor removal while carefully avoiding radiation and operative damage to healthy brain. Experimental and clinical data make an individualized treatment for each patient desirable.     

Stereotactic management of midline brain lesions.

Eighty-seven patients, aged 10 months to 92 years, with midline brain lesions were treated using stereotactic techniques at our institution between January 1987 and June 1990. A total of 119 stereotactic procedures were performed with no operative mortality. Procedures included 53 biopsies only, 22 endoscopic laser decompressions, 8 stereotactic microsurgical resections, 9 permanent implants of 125I, 12 temporary implants of 125I, 11 cyst aspirations, 2 cystoperitoneal shunts and 2 intracavitary 32P. The morbidity rate was 4.21%. Local anesthesia was used in 106 of the procedures (89%). Accurate diagnosis was achieved in all cases. Image guidance and stereotactic techniques open new frontiers in the diagnostic and therapeutic management of deep-seated midline intraparenchymal lesions.     

Intraoperative radiation therapy for patients with pancreatic carcinoma

The results of treatment with intraoperative and external beam radiation for patients with carcinoma of the pancreas are presented. Among patients treated with¹²⁵I implants for localized unresectable disease, local control rates ranged from 67% to 93% and median survival ranged from 7 to 12 months. In a series using intraoperative electron beam boosts, a 59% local control rate with a median survival of 16 months was achieved. Good palliation rates were achieved, although a high proportion of fatal complications occurred in one¹²⁵I series. Less promising results were seen in patients receiving intraoperative radiation following resections, with a local control rate of 50% and a median survival of 7 months in a series of 10 patients.

---

Resumen Se presentan los resultados del tratamiento con irradiación intraoperatoria y con irradiación externa para carcinoma de páncreas.Entre los pacientes tratados con implantes de yodo-125 para enfermedad localizada no resecable, las tasas de control local oscilaron entre 67% y 93% y la supervivencia media varió entre 7 y 12 meses. En una serie en la cual se utilizó una sobredosis intraoperatoria con haz de electrones, se logró una tasa de control local de 59% con una supervivencia media de 16 meses. En una de las series con I-125 se obtuvieron buenas tasas de paliación, aún cuando hubo una elevada proporción de complicaciones fatales. Resultados menos promisorios fueron observados en una serie de 10 pacientes que recibieron irradiación intraoperatoria después de la resección, con una tasa de control local de 50% y una supervivencia media de 7 meses.

---

---

Some of the material in this report was presented at the Annual Meeting of the American Surgical Association, Toronto, Canada, April 25–27, 1984, and published in the Annals of Surgery (in press). Supported in part by National Cancer Institute Contract No 1-CM-17481.     

Permanent iodine-125 implant and external beam radiation therapy for the treatment of malignant brain tumors.

Survival data of 114 patients treated for malignant brain tumors with 125I interstitial radiation therapy at Henry Ford Hospital, Detroit, Mich. (1986-1990), are presented. The first 64 patients were treated with temporary 125I implants with a total prescribed dose of 60 Gy at a dose rate of 40 cGy/h. In order to reduce the risk of injury to the surrounding normal tissue associated with high-dose brachytherapy, a new approach was initiated using permanent implants with a lower dose rate; 50 patients were treated after surgical resection with permanent implantation of 125I seeds at a lower dose rate of 4-7 cGy/h, with a total dose of 10,000-12,000 cGy, and concurrent external radiation therapy of 5,000 cGy. The rationale of this protocol was to increase the effectiveness of the low-dose-rate implant by a concurrent 'daily' boost of external radiation, thus inhibiting the proliferation of tumor cells during the protracted low-dose radiation treatment. Survival was compared between groups with permanent and temporary implants in terms of effectiveness in tumor control as well as impact on clinical condition. Low-dose-rate implant with concurrent external radiation therapy seems to offer the best chance for long-term survival without deterioration in the clinical condition.     

Interstitial irradiation with stereotactically implanted I-125 seeds for the treatment of cerebral glioma

Owing to its low rate of side effects and its high efficacy, interstitial irradiation with low-activity seeds should be the first therapeutic step in small (maximal diameter 40 mm), well-circumscribed, low-grade gliomas affecting the brain stem, other midline structures, or eloquent cerebral areas. In anaplastic gliomas, a therapeutic schedule using low-activity seeds and combining interstitial irradiation with radiotherapy (reduced boost dose of 15-30 Gy) seems to be more effective than interstitial irradiation alone. Compared with interstitial irradiation with high-activity seeds, this combined irradiation schedule caused no space-occupying radiation necrosis. Thus, it can be recommended as up-front treatment in patients with small (maximal diameter <40 mm) inoperable anaplastic gliomas. The use of high-activity I-125 seeds and interstitial irradiation at comparably high dose rates, integrating a small penumbra of normal brain tissue into the treatment volume, improved survival significantly in patients with primary highly malignant gliomas. In patients with recurrent tumors, the same treatment schedule did not substantially prolong survival compared with results obtained after resection plus radiotherapy. Owing to the high frequency of space-occupying radiation necrosis (40-60%), this schedule is only applicable in surgically accessible tumors. The application of low-activity I-125 seeds (in primary glioblastomas in combination with radiotherapy, in recurrent tumors without radiotherapy) yielded a median survival comparable with conventionally treated patients. There was no need for reoperation because of radiation necrosis. Thus, this treatment schedule is useful in both operable and surgically inaccessible glioblastomas.     

Permanent iodine-125 interstitial radiation therapy in the treatment of non-glioblastoma multiforme high-grade gliomas

BACKGROUND: This study evaluates prognostic factors influencing survival outcomes for 60 patients with permanent iodine-125 implants in the primary treatment of non-glioblastoma multiforme (GBM) high-grade gliomas. METHODS: Stereotactic treatment planning aimed to encompass the contrast-enhancing rim of the tumor visualized by CT, with an initial dose rate of 0.05 Gy/h with 125I, delivering 100 Gy at 1 year and 103.68 Gy at infinity. Survival was evaluated using the Kaplan-Meier method for univariate analysis and the Cox regressional method for multivariate analysis. In addition to the implant, 34 patients received external radiation therapy (5,000-6,000 cGy) before the implant; 13 patients were implanted without additional external beam radiation, and 13 patients underwent external radiation therapy before implant placement. RESULTS: With a mean follow-up of 77.6 months (range 3.5-164 months), 1-, 3-, 5- and 10-year survival were 86.7% (+/-0.05%), 60% (+/-0.07%), 50% (+/-0.07%) and 45.7% (+/-0.7%), respectively. The median survival time was 57 months. Second surgery was performed following the implant in 19 patients. Findings were tumor recurrence in 11 patients (22.5%), radiation necrosis in 7 patients (14.3%) and brain abscess in 1 patient (2%). Age, sex, tumor location, side of brain, tumor volume, Karnofsky score and neurological status were correlated with survival outcome. Favorable prognostic factors were age younger than 45 years, superficial tumor location and preoperative Karnofsky score greater than 70. RPA classification was used to define this group of patients. In RPA classes I and II (n = 43), 1-year survival was 93%, while 3-, 5- and 10-year survival was 67.4, 60.5 and 55.5%, respectively, and median survival time was 91 months. In RPA class III (n = 7), 1-year survival was 71.4%, while 3- and 5-year survival was 42.9 and 28.6%, respectively, and median survival time was 47 months. In RPA class IV (n = 10), 1-year survival was 60%, while 3-, 5- and 10-year survival was 50, 22.2 and 11.1%, respectively, and median survival time was 37 months. CONCLUSION: Brachytherapy with permanent implant of 125I appears promising in the treatment of primary non-GBM malignant gliomas. It improved survival time and reduced the incidence of complications and provided good quality of life. In order to further confirm these results, multicenter randomized prospective studies are needed. RPA analysis is a valid tool to define prognostically distinct survival groups. In this study, 2-year survival and median survival time were improved in all prognostic classes. This would suggest that selection bias alone does not account for the survival benefit seen with 125I implants. Further randomized studies with effective stratification are needed.     

Comparison of Radical Prostatectomy and Iodine 125 Interstitial Radiotherapy for the Treatment of Clinically Localized Prostate Cancer: A 7-Year Biochemical (PSA) Progression Analysis

Objectives. To evaluate the relative efficacy of brachytherapy to radical prostatectomy, we compared biochemical progression rates from a published series of men who underwent iodine 125 (¹²⁵I) interstitial radiotherapy for localized prostate cancer to a similar group of men who underwent anatomic radical prostatectomy using appropriate end points.Methods. Seventy-six men who underwent anatomic radical prostatectomy between 1988 and 1990 were carefully matched for Gleason score and clinical stage to a recently reported contemporary series of patients treated at another institution with ¹²⁵I brachytherapy without adjuvant treatment. The definition of biochemical progression was a serum PSA level greater than 0.2 ng/mL after anatomic radical prostatectomy and greater than 0.5 ng/mL for brachytherapy-treated patients.Results. The 7-year actuarial PSA progression-free survival following anatomic radical prostatectomy was 97.8% (95% confidence interval [CI], 85.6% to 99.7%) for this group of men selected to match the brachytherapy group, compared to 79% (95% CI not published) for men treated with ¹²⁵I interstitial radiotherapy.Conclusions. Using comparative end points for biochemical-free progression, failure rates may be higher following ¹²⁵I interstitial radiotherapy compared to anatomic radical prostatectomy. These data provide a better comparison of biochemical progression than previously published studies and emphasize the need for caution in interpreting the relative efficacy of brachytherapy in controlling localized prostate cancer.     

1.5T MRI引导125I粒子组织间插植治疗恶性肿瘤的可行性

目的评价1.5TMRI引导下^125I放射性粒子组织间植入治疗恶性肿瘤的可行性。方法对44例恶性肿瘤患者（男41例,女3例）共99个病灶在1.5TMRI引导下行^125I粒子永久性组织间植入。术前采用TPS系统设计治疗计划。采用fsFRFSET2WI（30s）、T1FSPGR（16s）、2DFIESTA（1s）、3DDynT1WI（15s）引导18GMR兼容性穿刺针插入病灶,并根据TPS计划植入^125I粒子。采用WHO实体瘤疗效评价标准评价疗效。结果穿刺针与^125I粒子在MR图像上均能清楚显示。49个病灶（49.49%）完全缓解;29个病灶（29.29%）明显缓解;14个病灶（14.14%）无变化;7个病灶进展（7.07%）。未见大出血和胆瘘等严重并发症发生。结论 MRI引导下^125I粒子组织间植入是一种安全有效的治疗恶性肿瘤的手段。     

Intraluminal appendiceal fluid is a predictive factor for recurrent appendicitis after initial successful non-operative management of uncomplicated appendicitis in pediatric patients

Background

The risk factors for recurrent appendicitis in pediatric patients are unclear. This study aimed to identify the predictive factors for recurrent appendicitis in pediatric patients who initially underwent successful non-operative management of uncomplicated appendicitis.

Methods

Potential predictive factors for recurrent appendicitis in terms of clinical characteristics, laboratory data, and abdominal ultrasonography and computed tomography findings, were evaluated.

Results

This study included 125 patients who underwent initial successful non-operative management of appendicitis. The rate of recurrent appendicitis was 19.2%, and the mean time to recurrence was 12.6 months. Univariate analyses found that rebound tenderness, muscle guarding, appendicoliths, appendiceal diameter > 9 mm, and intraluminal appendiceal fluid were associated with recurrent appendicitis.Multivariate analysis identified only intraluminal appendiceal fluid as an independent predictor of recurrent appendicitis.

Conclusions

Intraluminal appendiceal fluid is a predictive factor for recurrent appendicitis after initial non-operative management. The results of this study provide valuable information that may help to determine the appropriate management during the first episode of appendicitis.     

胆管腔内联合瘤体内植入~(125)I粒子治疗不可切除胰头癌

目的观察~(125)I粒子胆管腔内联合瘤体内植入治疗不可切除胰头癌(PHC)的效果。方法回顾性分析72例不可切除PTH患者的临床资料,其中37例接受胆管腔内联合瘤体内植入~(125)I粒子治疗(~(125)I组),35例接受腹腔镜姑息性手术(PS组),对比2组术后肝功能、并发症、中位生存时间及截止随访终点时生存率。结果与术前比较,2组术后1、3及6个月时血清总胆红素、丙氨酸氨基转移酶及天门冬氨酸氨基转移酶水平均降低,白蛋白水平均升高,且术后3、6个月时~(125)I组较PS组更为显著(P均0.05)。PS组术后并发症发生率为28.57%(10/35),~(125)I组为21.62%(8/37),组间差异无统计学意义(P=0.496)。PS组患者中位生存时间为9个月,~(125)I组为11个月,组间差异有统计学意义(P=0.041)。结论胆管腔内联合瘤体内植入~(125)I粒子可有效缓解PHC所致胆管梗阻症状,延长患者生存期。     

Interstitial brachytherapy for low-grade cerebral gliomas: Analysis of results in a series of 36 cases

Summary The results obtained with interstitial brachytherapy in thirty-six low-grade cerebral gliomas (2 pilocytic astrocytomas, 23 astrocytomas and 11 oligodendrogliomas) are reported (mean follow-up: 75 months, range 37–159). All tumours were situated in locations which did not call for surgical removal as the treatment of choice. Their volume ranged from 4 to 82 cc (m=32); the Karnofsky performance status (KPS) of the treated patients lay between 0.60 and 0.90.The sources utilized (Iridium-192 in 32 cases and Iodine-125 in 4) were implanted permanently in 22 patients and temporarily in 14, using the Talairach stereotactic apparatus. The mean peripheral dose was 89.7 Gy for the permanent implants and and 42.8 Gy with a rate of 32.05 cGy/h for the temporary implants. External beam irradiation was added for tumour volumes greater than 35 cc (19 cases) on a second target volume extending 2 cm beyond the tumoural borders treated with interstitial irradiation.The survival estimates for the entire group showed a probability of 82.9% at 60 months, of 56.8% at 96, 39.4% at 120 (m.s.t.: 112 months). The quality of life in the treated patients was satisfactory, KPS never falling below a mean score of 0.70. The extent of the target volume turned out to be the most significant factor influencing survival at the multivariate analysis. Severe neurological impairment due to radionecrosis occurred in 4 patients (11%), three of them requiring surgical decompression. Target volume and radiation dose showed a direct correlation with the risk of radionecrosis at the regression analysis, the critical values being 35 cc and 100 Gy (permanent implants) or 50 Gy (42 cGy/h, temporary implants) respectively. The analysis of the results indicates that, even though many questions still remain open, brachytherapy can represent a valid alternative to surgery for tumours not suitable for surgical removal.Study partially supported by a grant from the Italian Ministry of University and of Scientific and Technological Research.     

Long-term outcome of 89 low-grade brain-stem gliomas after interstitial radiation therapy

Between 1974 and 1985, 89 patients suffering from histologically confirmed, nonresectable low-grade astrocytomas located in the brain stem were entered into a retrospective study. Iodine-125 (125I) was implanted in 29 patients and iridium-192 (192Ir) in 26 patients. Computerized tomography revealed that 78% of the tumors in these patients were located chiefly in the mesencephalic region, 70% were circumscribed, and 78% were contrast-enhanced. Thirty-four patients underwent biopsy without prior aggressive tumor-specific therapy such as chemotherapy or external beam irradiation. Among these, 70% of the tumors were located predominantly in the pons, 74% were diffuse, and 59% were hypodense or isodense after contrast enhancement. Long-term follow-up investigations indicated that life expectancy after interstitial radiation therapy with 125I implanted directly by catheter either permanently or temporarily showed a more favorable trend than that after treatment with 192Ir. Interstitial radiation therapy with 125I appears to be an effective treatment for slowly proliferating, differentiated, well-delineated, nonresectable brain-stem gliomas. This technique makes it possible to achieve radiosurgical tumor control and, when carefully applied, represents the least traumatic treatment. Reduction of the tumor mass brings about improvement of the clinical symptoms. Further investigations on the biological behavior of brain-stem gliomas and prospective randomized long-term follow-up studies are necessary to evaluate the different kinds of treatment available for these patients.     

Interstitial irradiation and hyperthermia for the treatment of recurrent malignant brain tumors

Between June 1987 and June 1989, 29 recurrent malignant gliomas or recurrent solitary brain metastases in 28 patients were treated in a Phase I study of interstitial irradiation and hyperthermia. Patient age ranged from 18 to 65 years, and the Karnofsky Performance Status scores ranged from 40 to 90%. There were 13 glioblastomas, 10 anaplastic astrocytomas, 3 melanomas, and 3 adenocarcinomas. Catheters were implanted stereotactically after computed tomography-based preplanning. Hyperthermia was administered before and after brachytherapy, using one to six 2450- or 915-MHz helical coil microwave antennas and one to three multisensor fiberoptic thermometry probes. The goal was to heat as much of the tumor as possible to 42.5 degrees C for 30 minutes. Within 30 minutes after the first hyperthermia treatment, implant catheters were afterloaded with high-activity iodine-125 seeds delivering tumor doses of 32.6 to 61.0 Gy. Most patients had no sensation of heating. Complications included seizures in 5 patients, reversible neurological changes in 9 patients, a scalp burn in 1, and infections in 3. Of 28 evaluable 2-month follow-up scans, 11 showed definite improvement in the radiological appearance of the tumor, 4 were slightly improved, 7 were stable, and 6 showed tumor progression. Ten patients underwent reoperation for persistent tumor and/or necrosis. Eleven of 28 patients are alive 40 to 97 weeks after treatment. Thirteen patients died of a brain tumor, 2 died of extracranial melanoma metastases, 1 died of new brain melanoma metastases, and 1 died of a pulmonary embolus. The median survival was 55 weeks overall. Median survival has not yet been reached for the anaplastic astrocytoma subgroup. We conclude that interstitial brain hyperthermia using helical coil microwave antennas is technically feasible. The level of toxicity is acceptable, and the computed tomographic response rate is encouraging.     

Amino acid study of cerebral gliomas using positron emission tomography--analysis of (11C-methyl)-L-methionine uptake index.

Sixteen patients with gliomas (7 low grade, 9 high grade) were examined using positron emission tomography (PET) with intravenous administration of 22.2 MBq/kg (0.6 mCi/kg) of (11C-methyl)-L-methionine (C-11 Met). The tracer uptake in regions of interest was calculated on PET images taken 45 minutes after injection; the uptake index was represented as a percentage of the total count in the arterial blood summed over 45 minutes. C-11 Met uptake indices in the tumors ranged from 0.020 to 0.041% with a mean of 0.032% for the low-grade gliomas and from 0.013 to 0.044% with a mean of 0.036% for the high-grade gliomas. These indices significantly increased as compared with those in the contralateral gray matter (0.008-0.032% with a mean of 0.023%; p less than 0.01 vs. low-grade gliomas, p less than 0.001 vs. high-grade gliomas). In the low-grade gliomas, C-11 Met PET images clearly depicted the existence and even the extent of the tumors, although x-ray computed tomography (CT) did not always distinguish tumoral lesions. In the high-grade gliomas, the areas of tracer accumulation regionally extended to peritumoral low density on CT scans, where malignant tumor cell infiltration was proved by operative and follow-up CT findings. C-11 Met may be a useful radiopharmaceutical for differential diagnosis of gliomas, and the accuracy of tumor localization will give us a better rationale in therapeutic strategies for surgery and radiation therapy of gliomas.