The Application of Number Needed to Treat (NNT) to Clinical Problems in Radiotherapy

The goals of this report are: 1) to review the number needed to treat (NNT) concept, which, although well established in many sectors of medicine, is still relatively new to the radiotherapy community; 2) to discuss several clinical radiotherapy examples illustrating the inherent advantages of the NNT approach; and 3) to discuss potential future roles of the NNT concept within radiotherapy.     

An unusual neck lump: intramuscular haemangioma of the sternocleidomastoid muscle

Neck lumps can often present a diagnostic dilemma, with a wide pre-operative differential diagnosis. We present an unusual case of an intramuscular haemangioma arising in the sternocleidomastoid muscle. Pre operative diagnosis is often difficult, as these lesions are extremely rare in the head and neck region and only few sporadic cases have been reported in the literature. We report the presentation diagnosis and management of intramuscular haemangiomas of the sternocleidomastoid muscle.     

In vivo circumvention of human colon carcinoma resistance to bleomycin.

Metabolic inactivation of bleomycin (BLM) by cysteine proteinase-like enzymes is thought to be a major mechanism of BLM tumor resistance. We now report that the human colon carcinoma COLO-205 is highly resistant to BLM and that E-64, a cysteine proteinase inhibitor, sensitizes COLO-205 to BLM. Treatment of COLO-205-bearing nude mice with either E-64 (40 mg/kg) or BLM (10 mg/kg) alone did not inhibit COLO-205 growth. However, pretreatment with E-64 prior to BLM prevented these xenografts from growing. Analysis by high performance liquid chromatography of in vivo BLM metabolism following [3H]BLM A2 treatment of COLO-205-bearing nude mice showed a different metabolic profile among the various organs and the tumor. Whereas [3H]BLM A2 was the only major radioactive peak detected in sera and tumors, several metabolites, including deamido-BLM A2, were found in kidney, liver, and lung as early as 15 min. Pretreatment of mice with E-64 inhibited tumor, kidney, and lung BLM A2 metabolism. Furthermore, pretreatment with E-64 increased BLM A2 accumulation in tumors (6.1-fold), kidney (4.0-fold), lung (2.8-fold), liver (1.8-fold), and serum (1.7-fold). E-64 pretreatment did not enhance the major toxicity of BLM, pulmonary fibrosis, as determined by both lung hydroxyproline levels and histopathology. Thus, the cysteine proteinase inhibitor E-64 affects the metabolic fate and the levels of accumulation of BLM in vivo. These results demonstrate that resistance of human COLO-205 tumors to BLM can be circumvented by E-64 without enhancement of the major side effect of BLM, suggesting a possible clinical use of this combination therapy.     

Mersacidin, a new antibiotic from Bacillus. In vitro and in vivo antibacterial activity.

Mersacidin is a new peptide antibiotic of the proposed lantibiotic family. It is active in vitro and in vivo against Gram-positive bacteria including the methicillin-resistant Staphylococci. Its in vitro activity is less than those of vancomycin and erythromycin but it shows much higher activity in the in vivo system than can be expected from the in vitro testing results. A water soluble potassium salt has been prepared which has an activity profile similar to that of mersacidin, but has better in vivo activity against Streptococcus pyogenes than the parent compound.     

A differential efficiency of adenovirus-mediated in vivo gene transfer into skeletal muscle cells of different maturity

High titre (10¹¹–10¹² pfu/ml) suspensions of autonomouslyreplication-defective type 5 human adenovirus (AV) recombinantswith different reporter gene inserts (CMV-Luciferase (Lux),CMV-ß-galactosidase (Lac Z), RSV-Lux and RSV-Lac Z)were injected Into intact quadrlceps muscles of 1–5 dayold (Group 1) or 35–45 day old (Group 2) normal mice,as well as regenerating adult mouse muscles (Group 3) and 35day old mdx muscles (Group 4). The expression of the reportergenes was quantitated 10 days and 2 months later. At 10 dayspostinjection all reporter gene expression was very high inthe neonatally injected (Group 1) muscles. In Group 2 musclesthe transduction was markedly less. In Group 3 muscles the geneexpression was significantly better than in the Group 2 muscles.In adult mdx muscles (Group 4) where spontaneous regenerationis usually present, the results were similar to those in Group3 animals. At 2 months post-injection in Group 1 animals, theRSV-Lux expression was even higher than at 10 days postinjection.The cell surface density of     

Quantitative comparison between two phase contrast techniques: diffraction enhanced imaging and phase propagation imaging

Two x-ray phase contrast imaging techniques are compared in a quantitative way for future mammographic applications: diffraction enhanced imaging (DEI) and phase propagation imaging (PPI). DEI involves, downstream of the sample, an analyser crystal acting as an angular filter for x-rays refracted by the sample. PPI simply uses the propagation (Fresnel diffraction) of the monochromatic and partially coherent x-ray beam over large distances. The information given by the two techniques is assessed by theoretical simulations and compared at the level of the experimental results for different kinds of samples (phantoms and real tissues). The imaging parameters such as the energy, the angular position of the analyser crystal in the DEI case or the sample to detector distance in the PPI case were varied in order to optimize the image quality in terms of contrast, visibility and figure of merit.     

Particle analysis for the determination of UHMWPE wear

Three types of ultrahigh molecular weight polyethylene (UHMWPE) acetabular liners were tested against cobalt-chrome (CoCr) femoral heads on a hip simulator to approximately 20 million cycles. The materials included (1) conventional, nonirradiated liners (C-PE); (2) 5 Mrad gamma-irradiated, remelted, and artificially aged liners (5-XPE); and (3) 10 Mrad gamma-irradiated, remelted, and artificially aged liners (10-XPE). Wear was quantified by gravimetric analysis and wear particle characterization. Particle number and morphology were quantified by scanning electron microscopy (SEM) and compared between groups. Atomic force microscopy (AFM) was used to measure particle height in an effort to improve the total wear volume estimation. The wear debris, as characterized by SEM, was predominantly submicron and round, with occasional fibrils documented in the C-PE material. AFM analysis showed that particle height was approximately one-third of the particle equivalent circular diameter for all three materials. This correlation was used to improve the estimation of volumetric wear rate through SEM particle analysis. This technique is particularly useful for high-dose crosslinked UHMWPE, such as 10-XPE, which show weight gain due to fluid absorption during wear testing. This study has shown that particle analysis provides additional particle morphology and quantity information that cannot be obtained through gravimetric analysis.     

Cast immobilization in bayonet position versus reduction and pin fixation of overriding distal metaphyseal radius fractures in children under ten years of age: a case control study

PurposeCompletely displaced distal radius fractures in children have been traditionally reduced and immobilized with a cast or pin fixed. Cast immobilization leaving the fracture displaced in the bayonet position has been recently suggested as a non-invasive and effective treatment alternative. This is a pilot comparative study between reduction and no reduction.MethodsWe assessed subjective, functional and radiographic outcome after a minimum 2.5-year follow-up in 12 children under ten years of age who had sustained a completely displaced metaphyseal radius fracture, which had been immobilized leaving the fracture in an overriding position (shortening 3 mm to 9 mm). A total of 12 age-matched patients, whose similar fractures were reduced and pin fixed, were chosen for controls. ResultsAt follow-up none of the 24 patients had visible forearm deformity and the maximal angulation in radiographs was 5° Forearm and wrist movement was restored (< 10° of discrepancy) in all 24 patients. Grip strength ratio was normal in all but three surgically treated patients. All patients had returned to their previous activities. One operatively treated boy who was re-operated on reported of pain (visual analogue scale 2).ConclusionThe results of this study do not demonstrate the superiority of reduction and pin fixation over cast immobilization in the bayonet position of closed overriding distal metaphyseal radius fractures in children under ten years with normal neurovascular findings.Level of evidenceIII     

Simulator trials to determine the wear of the combination aluminium oxide ceramic-carbon fibre reinforced plastic (CFRP) used as an insert in a hip socket

Hip simulator trials were conducted to determine the initial wear between alumina femoral heads and carbon fibre reinforced plastic (CFRP, CAPROMAN) insert in a titanium socket. A force of 2500 N and a frequency of 0.857 H were applied. Using surface and sphericity measurement techniques, the amount of wear was determined. After 500,000 cycles, the centre of the head had moved by 10 μm into the insert, and the average radius increased by 2 μm. After 1 million cycles, the additional changes were less than 1 μm. Based on an examination of retrieved implants (wear rate: 6.1 μm/year) and based on the simulator results, the combination alumina-CFRP inserts could be approved for total hip replacement. Received: 5 March 1998