Resection and brain brachytherapy with permanent iodine-125 sources for brain metastasis

OBJECTIVE Stereotactic radiosurgery (SRS) with or without whole-brain radiotherapy can be used to achieve local control (> 90%) for small brain metastases after resection. However, many brain metastases are unsuitable for SRS because of their size or previous treatment, and whole-brain radiotherapy is associated with significant neurocognitive morbidity. The purpose of this study was to investigate the efficacy and toxicity of surgery and iodine-125 (¹²⁵I) brachytherapy for brain metastases. METHODS A total of 95 consecutive patients treated for 105 brain metastases at a single institution between September 1997 and July 2013 were identified for this analysis retrospectively. Each patient underwent MRI followed by craniotomy with resection of metastasis and placement of ¹²⁵I sources as permanent implants. The patients were followed with serial surveillance MRIs. The relationships among local control, overall survival, and necrosis were estimated by using the Kaplan-Meier method and compared with results of log-rank tests and multivariate regression models. RESULTS The median age at surgery was 59 years (range 29.9-81.6 years), 53% of the lesions had been treated previously, and the median preoperative metastasis volume was 13.5 cm³ (range 0.21-76.2 cm³). Gross-total resection was achieved in 81% of the cases. The median number of ¹²⁵I sources implanted per cavity was 28 (range 4-93), and the median activity was 0.73 mCi (range 0.34-1.3 mCi) per source. A total of 476 brain MRIs were analyzed (median MRIs per patient 3; range 0-22). Metastasis size was the strongest predictor of cavity volume and shrinkage (p < 0.0001). Multivariable regression modeling failed to predict the likelihood of local progression or necrosis according to metastasis volume, cavity volume, or the rate of cavity remodeling regardless of source activity or previous SRS. The median clinical follow-up time in living patients was 14.4 months (range 0.02-13.6 years), and crude local control was 90%. Median overall survival extended from 2.1 months in the shortest quartile to 62.3 months in the longest quartile (p < 0.0001). The overall risk of necrosis was 15% and increased significantly for lesions with a history of previous SRS (p < 0.05). CONCLUSIONS Therapeutic options for patients with large or recurrent brain metastases are limited. Data from this study suggest that resection with permanent ¹²⁵I brachytherapy is an effective strategy for achieving local control of brain metastasis. Although metastasis volume significantly influences resection cavity size and remodeling, volumetric parameters do not seem to influence local control or necrosis. With careful patient selection, this treatment regimen is associated with minimal toxicity and can result in long-term survival for some patients. ▪ CLASSIFICATION OF EVIDENCE Type of question: therapeutic; study design: retrospective case series; evidence: Class IV.

Cold spot mapping inferred from MRI at time of failure predicts biopsy-proven local failure after permanent seed brachytherapy in prostate cancer patients: implications for focal salvage brachytherapy

BACKGROUND AND PURPOSE

(1) To establish a method to evaluate dosimetry at the time of primary prostate permanent implant (pPPI) using MRI of the shrunken prostate at the time of failure (tf). (2) To compare cold spot mapping with sextant-biopsy mapping at tf.

MATERIAL AND METHODS

Twenty-four patients were referred for biopsy-proven local failure (LF) after pPPI. Multiparametric MRI and combined-sextant biopsy with a central review of the pathology at tf were systematically performed. A model of the shrinking pattern was defined as a Volumetric Change Factor (VCF) as a function of time from time of pPPI (t0). An isotropic expansion to both prostate volume (PV) and seed position (SP) coordinates determined at tf was performed using a validated algorithm using the VCF.

RESULTS

pPPI CT-based evaluation (at 4weeks) vs. MR-based evaluation: Mean D90% was 145.23±19.16Gy [100.0-167.5] vs. 85.28±27.36Gy [39-139] (p=0.001), respectively. Mean V100% was 91.6±7.9% [70-100%] vs. 73.1±13.8% [55-98%] (p=0.0006), respectively. Seventy-seven per cent of the pathologically positive sextants were classified as cold.

CONCLUSIONS

Patients with biopsy-proven LF had poorer implantation quality when evaluated by MRI several years after implantation. There is a strong relationship between microscopic involvement at tf and cold spots.

An unfolded variant of the major peanut allergen Ara h 2 with decreased anaphylactic potential

BACKGROUND

Peanut allergy causes severe type 1 hypersensitivity reactions and conventional immunotherapy against peanut allergy is associated with a high risk of anaphylaxis.

OBJECTIVE

Our current study reports proof of concept experiments on the safety of a stably denatured variant of the major peanut allergen Ara h 2 for immunotherapy. We determined the impact of structure loss of Ara h 2 on its IgE binding and basophil degranulation capacity, T cell reactivity as well as anaphylactic potential.

METHODS

The secondary structure of untreated and reduced/alkylated Ara h 2 variants was determined by circular dichroism spectroscopy. We addressed human patient IgE binding to Ara h 2 by ELISA and Western blot experiments. RBL-SX38 cells were used to test the degranulation induced by untreated and reduced/alkylated Ara h 2. We assessed the anaphylactic potential of Ara h 2 variants by challenge of sensitized BALB/c mice. T cell reactivity was investigated using human Ara h 2-specific T cell lines and splenocytes isolated from sensitized mice.

RESULTS

Reduction/alkylation of Ara h 2 caused a decrease in IgE binding capacity, basophil degranulation and anaphylactic potential in vivo. However, the human T cell response to reduced/alkylated and untreated Ara h 2 was comparable. Mouse splenocytes showed higher metabolic activity upon stimulation with reduced/alkylated Ara h 2 and released similar IL-4, IL-13 and IFNγ levels upon treatment with either Ara h 2 variant.

CONCLUSIONS AND CLINICAL RELEVANCE

Reduced/alkylated Ara h 2 might be a safer alternative than native Ara h 2 for immunotherapeutic treatment of peanut allergic patients.

Dosimetric analysis of radiation therapy oncology group 0321: the importance of urethral dose

PURPOSE

Radiation Therapy Oncology Group 0321 is the first multi-institutional cooperative group high-dose-rate (HDR) prostate brachytherapy trial with complete digital brachytherapy dosimetry data. This is a descriptive report of the data and an analysis of toxicity.

METHODS AND MATERIALS

Patients are treated with external beam radiation therapy at 45 Gy and 1 HDR implant with 19 Gy in 2 fractions. Implants are done with transrectal ultrasound guidance, and computed tomography (CT)-compatible nonmetallic catheters. HDR planning is done on ≤3-mm-thick CT slices. The "mean DVH" (dose-volume histogram) of the planning target volume (PTV), implanted volume (IP), and organs at risk are calculated. This includes the mean and standard deviation (SD) of the volume at 10-percentage-point intervals from 10% to 200% of the prescribed dose. The conformal index (COIN), homogeneity index (HI), catheters per implant, and patients per institution are calculated. Multivariate analysis and hazard ratios calculation of all the variables against reported grade ≥2 (G2+) genitourinary (GU) adverse events (Common Terminology Criteria for Adverse Events, version 3) are performed.

RESULTS

Dosimetry data are based on 122 eligible patients from 14 institutions. The mean of PTV, IP, catheters per implant, and patients per institution are 54 cc, 63 cc, 19 and 9, respectively. The mean of %V100PTV, V80Bladder, V80Rectum, and V120Urethra were 94%, 0.40 cc, 0.15 cc, and 0.25 cc, respectively. There are too few G2+ gastrointestinal adverse event (GI AE) for correlative analysis; thus, the analysis has been performed on the more common G2+ GU AE. There are positive correlations noted between both acute and late G2+ GU AE and urethral dose at multiple levels. Positive correlations with late AE are seen with PTV and IP at high-dose levels. A negative correlation is seen between HI and acute AE. A higher patient accrual rate is associated with a lower rate of G2+ acute and late AE.

CONCLUSIONS

Higher urethral dose, larger high-dose volumes, and lower dose homogeneity are associated with greater toxicities. A mean dose-volume histogram comparison at all dose levels should be used for quality control and future research comparison.

Monitoring neutrophils and platelets during casein-induced anaphylaxis in an experimental BALB/c mouse model

BACKGROUND

With respect to the cellular players, mast cells and basophils have been well studied in experimental murine systemic anaphylaxis models, but the role of neutrophils and platelets is not fully understood today.

OBJECTIVE

We tested the hypothesis that neutrophils and platelets might participate in an antigen-induced anaphylaxis model.

METHODS

BALB/c mice were sensitized intraperitoneally with alum-adsorbed casein. A period of 2 weeks later, mice were challenged with 100 μg casein intravenously and immediate hypersensitivity reactions were assessed by rectal temperature measurements and monitoring the physical activity. Subsequently, leucocytes were counted in the peripheral blood as well as quantified in situ in typical shock organs like lung, liver and spleen, heart and kidney.

RESULTS

Mice sensitized with casein showed casein-specific IgG1, IgE, and IgG2a. When sensitized mice were specifically challenged with casein they developed immediate hypersensitivity reactions including drop of temperature and reduced activity. Furthermore, pronounced peripheral neutropenia and reduced platelet counts correlated with the severity of the hypersensitivity reactions. In the histological analyses of collected tissues we observed lung interstitial neutrophilia using Gr-1 staining. These events occurred specifically in mice sensitized and challenged with casein, in contrast to control groups.

CONCLUSIONS

On the basis of our data we suggest that in addition to mast cells and basophils, neutrophils and platelets participate in the anaphylactic response in this BALB/c mouse model. Platelet and neutrophils expressing relevant immunoglobulin receptors may therefore have a synergistic effect with allergen specific IgE as well as IgG antibodies in food-induced anaphylaxis. We suggest that management of these cells could be of clinical importance to handle anaphylaxis.

Studies on skeletal muscle biopsies in endemic skeletal fluorosis

Neurological manifestations of skeletal fluorosis have been attributed to compressive radiculomyelopathy. Experimental fluorosis has shown evidence of myopathic changes. Data on human muscle pathology is very scanty. This study included 22 patients with established osteofluorosis. 16 of them showed only EMG changes of neurogenic muscle disease. Histochemistry and histopathology of muscle biopsies showed features of muscle atrophy, evidenced by 'type I' atrophy and 'type I' grouping. No myopathic changes were observed. It may be concluded that the primary changes are related to the nerve, with muscle being affected secondarily. There was no evidence of any primary muscle pathology due to fluorosis.

Asymmetric synthesis for process research

During the past few years, asymmetric synthetic methods have become an indispensable tool in the process research arena for the production of enantiopure materials. The development of a truly efficient, reliable and economically viable asymmetric synthesis is still limited, and searches for such valuable technologies are rapidly growing. This review features an overview of several interesting articles which appeared in the literature from January 1998, through to August 1999, that can greatly impact the area of asymmetric synthesis in process research and development.

Haemodynamic and blood gas changes in buffaloes (Bubalus bubalis) in the supine position following thiopentone anaesthesia with premedication

Studies were undertaken on seven adult female buffaloes (Bubalus bubalis) premedicated with triflupromazine hydrochloride (0.3 mg/kg) and chloral hydrate (30 mg/kg). Anaesthesia was induced with thiopentone sodium (10 mg/kg) and animals were kept under intermittent positive pressure ventilation. Measurements were made for 30 min in the lateral position, for 20 min in the supine position and subsequently for 40 min again in the lateral position. Regurgitation during anaesthesia was avoided by evacuation of the rumen by rumenotomy two days prior to the experiment. When animals were in the lateral position there were minimal changes in arterial pressure and heart rate but central venous pressure rose. These changes were related to intermittent positive pressure ventilation. In the supine position, increase in heart rate (28%) was associated with profound hypotension (56%) and decrease in central venous pressure (171%) in these animals. There was a fall in venous oxygen tension and a marked increase (91%) in oxygen extraction ratio. Restoration to the lateral position ameliorated all these changes rapidly. It was suggested that a 'low pressure-low flow' circulatory state exists in anaesthetised adult buffaloes in the supine position.

Patho-anatomy of herniation of the reticulum through the diaphragm in the bovine

Dissection of embalmed and untreated water buffalo carcasses (n=10) revealed that hernias had occurred at the musculotendinous junction of the diaphragm, ventral to the foramen venae cavae and slightly lateral to the median plane. The diameter of the hernial ring varied from 7 cm to 20 cm. Herniation was more common in the right thoracic cavity with the reticulum firmly adherent to the hernia ring. Adhesions between the herniated portion of the reticulum and pleura, lung, pericardium or thoracic wall were present, while in a few cases thick fibrous tracts concealing metallic bodies were found. In two cases, involvement of esophageal groove with malalignment of cardia and reticulo-omasal opening was observed. Displacement and compression of the heart was observed in four animals.