Diethylstilbestrol (DES) labeled with Auger emitters: Potential radiopharmaceutical for therapy of estrogen receptor-positive tumors and their metastases?

Purpose: Diethylstilbestrol (DES) is a well-known, non-steroidal estrogen with high affinity to the estrogen receptor (ER). Labeled DES would be a useful tool for therapy of ER-positive mammary carcinomas and their metastases. Particularly with Auger emitters, high cytotoxic potential combined with only slight side effects can be expected.

Materials and methods: DES was labeled by a new method with higher yield and specific activity than former methods. Cytotoxic effects on MCF-7 (human, Caucasian, breast, adenocarcinoma) cells, were tested in relation to radioactivity concentration applied and location of decay. Different iodine isotopes (¹²³I, ¹²⁵I, ¹³¹I) bound to DES or in the form of iodide were compared with regard to induction of intracellular DNA (deoxyribonucleic acid) fragmentation, and decrease of viability. For this purpose the ‘Cell Death Detection Enzyme-Linked ImmunoSorbent Assay (ELISA)’ and the water soluble tetrazolium salt WST-1 were used. The radiation protective effects of the radical scavenger vitamin C were also tested.

Results: The experiments showed a significantly lower viability of cells exposed to the Auger emitters than those with the β-emitter ¹³¹I. All nuclides induced intracellular DNA fragments. The maximum amount of intracellular DNA fragments was different for all nuclides: ¹³¹I-DES <¹²⁵I-DES <¹²³I-DES. With isotopes in the form of iodide, no increase of intracellular DNA fragmentation could be detected. Vitamin C reduced intracellular DNA fragmentation significantly, which points to an induction mechanism mainly via free radicals.

Conclusions: Labeled DES is a promising compound with high cytotoxic potential for treatment of ER-positive mamma carcinomas and their metastases.     

Validity study of the standing test for imbalance and disequilibrium (SIDE): Is the amount of body sway in adopted postures consistent with item order?

The standing test for imbalance and disequilibrium (SIDE) is a discriminative measure developed for the purpose of identifying balance deficits that may cause falls. The purpose of the present study was to determine the validity of the sequence of postures used in SIDE. Subjects comprised 30 men with a mean (±standard deviation) age of 21.9 ± 3.11 years (range 19–32 years) and 30 women with a mean age of 20.7 ± 1.24 years (range 19–23 years). Center of pressure (COP) was measured using a stabilometer recording for 30 s with a 20-Hz sampling frequency. The measurement postures that were similar to postures adopted in the SIDE were: standing with feet 20 cm apart; standing with legs close and the insides of both feet touching; two tandem standing positions (with the dominant foot forward and with the non-dominant foot forward); and two single-leg standing positions (on the dominant foot and on the non-dominant foot). We calculated total path length and envelopment area of sway from the COP data. Statistical differences in means were determined using the Tukey–Kramer multiple comparison test. Results indicate that the orders of total path length and envelopment areas of sway in each posture were consistent with the item order of SIDE. Significant differences existed between the means of total path length and envelopment areas of sway in each posture (p < 0.05), with the exception of both tandem standing positions and both one-leg standing positions. The item order of SIDE appears to show concurrent validity in terms of the amount of body sway in the adopted postures.     

Differential diagnosis of tumours and tumour-like lesions of the infrapatellar (Hoffa’s) fat pad: pictorial review with an emphasis on MR imaging

A variety of intrinsic and extrinsic tumours and tumour-like conditions may affect the infrapatellar (Hoffas) fat pad (IFP). MR imaging is the technique of choice in evaluating these conditions, but correlation with radiographs is important to identify those lesions producing mineralization. This pictorial review illustrates the spectrum of mass-like lesions that can affect the IFP, emphasizing the radiographic and MR findings that suggest a specific diagnosis.