Vascular Wall Maturation and Prolonged Angiogenic Effect by Endothelial-Specific Platelet-Derived Growth Factor Expression

BACKGROUND

The implementation of angiogenic gene therapy at clinics is hindered by the transience of the therapeutic effect. Recruiting vascular wall smooth muscle cells, a process termed 'maturation', can stabilize newly formed vessels.

OBJECTIVE

To induce angiogenesis followed by vessel maturation in a murine ischemic limb model by endothelial cell-specific promoter regulated expression of vascular endothelial growth factor (VEGF) and platelet-derived growth factor-BB (PDGF-BB).

METHODS

We constructed adenoviral vectors containing angiogenic factors VEGF and PDGF-B regulated by a modified preproendothelin-1 (PPE-1-3x) promoter and investigated their angiogenic effect in a murine ischemic limb model.

RESULTS

VEGF gene therapy increased perfusion and the vessel density in the limb shortly after expression with PPE-1-3x promoter or cytomegalovirus (CMV) promoter vectors, but only PPE-1-3xVEGF treatment exhibited a sustained effect. Expression of PDGF-B by PPE-1-3x promoter resulted in morphological maturation of the vasculature and further increased the perfusion, while nonspecific expression of PDGF-B with CMV promoter had no therapeutic effect. Regulation of dual therapy with VEGF and PDGF-B by PPE-1-3x promoter resulted in an early-onset, sustained angiogenic effect accompanied by vessel maturation.

CONCLUSIONS

Systemic gene therapy with the angiogenic factors VEGF and PDGF-B under angiogenic- endothelial cell-specific regulation was effective in inducing functionally and morphologically mature vasculature.

Stensen Duct Rupture (Sialocele) and Other Complications of the Aptos Thread Technique

BACKGROUND

The Aptos thread technique is a mode of uplifting the flabby soft tissue of the aging face. Permanent suture material made of polypropylene monofilament with dents is used in this technique. This procedure is gaining popularity throughout the world. According to the literature, several hundred Aptos procedures have been performed, and no major complications have been reported yet.

METHODS

Two adult women presented shortly after the Aptos thread insertion. They sustained devastating results. A close study was performed to understand and learn the potential complications.

RESULTS

The authors present two major complications, a rare case of Stensen's duct laceration and a case of chronic inflammation mandating surgical treatment.

CONCLUSIONS

Describing complications may teach plastic surgeons more about this method and how to avoid similar devastating side effects in the future.

Ex vivo activated human macrophages improve healing, remodeling, and function of the infarcted heart

BACKGROUND

Activated macrophages have a significant role in wound healing and damaged tissue repair. We sought to explore the ability of ex vivo activated macrophages to promote healing and repair of the infarcted myocardium.

METHODS AND RESULTS

Human activated macrophage suspension (AMS) was prepared from a whole blood unit obtained from young donors in a closed sterile system and was activated by a novel method of hypo-osmotic shock. The AMS (approximately 4 x 10(5) cells) included up to 43% CD14-positive cells and was injected into the ischemic myocardium of rats (n=8) immediately after coronary artery ligation. The control group (n=9) was treated with saline injection. The human cells existed in the infarcted heart 4 to 7 days after injection, as indicated by histology, human growth hormone-specific polymerase chain reaction, and magnetic resonance imaging (MRI) tracking of iron oxide-nanoparticle-labeled cells. After 5 weeks, scar vessel density (+/-SE) (25+/-4 versus 10+/-1 per mm2; P<0.05), myofibroblast accumulation, and recruitment of resident monocytes and macrophages were greater in AMS-treated hearts compared with controls. Serial echocardiography studies, before and 5 weeks after injection, showed that AMS improved scar thickening (0.15+/-0.01 versus 0.11+/-0.01 cm; P<0.05), reduced left ventricular (LV) diastolic dilatation (0.87+/-0.02 versus 0.99+/-0.04 cm; P<0.05), and improved LV fractional shortening (31+/-2 versus 20+/-4%; P<0.05), compared with controls.

CONCLUSIONS

Early after myocardial infarction, injection of AMS accelerates vascularization, tissue repair, and improves cardiac remodeling and function. Our work suggests a novel clinically relevant option to promote the repair of ischemic tissue.

Laser Treatment of Venous Malformations

Venous malformations (VM) are developmental errors comprised of enlarged dysplastic blood vessels. Clinically they manifest as either a faint blue patch or a soft blue vascular mass. Treatment options include a sclerosing agent (such as alcohol or ethiblock), surgery or laser therapy. A review of the literature concerning VM and laser treatment yielded a few sporadic reports describing series of 3 to 46 cases. In this retrospective study we reviewed the files of the relevant cases. The data included the extent of the lesion, the different anatomical sites, age of patient and the extent of clearance of the lesion as the treatment's end point. This study includes 56 cases which makes it the largest series presented. The success rate of laser treatment was 92.8%. The immediate complication rate was very low (approximately 3.57%) including minimal scarring and deformity. No long term complications were noted. Our study concludes that treatment of VM is a difficult task due to the nature of the lesions. Laser treatment of these lesions enables one to obtain good results with a very low incidence of complications. Surgery and other treatment modalities are not always satisfactory, yield similar or less efficient results and have a higher complication rate. Laser treatment can play an important role in the treatment of VM and in fact may be the treatment of choice in some settings.

Nitrous Oxide Administered by the Plastic Surgeon for Repair of Facial Lacerations in Children in the Emergency Room

BACKGROUND

The purpose of this study was to investigate a means of providing pain relief during repair of facial lacerations in children in the emergency room.

METHODS

This study was conducted in the emergency room of a tertiary care, university-affiliated hospital. Fifty percent nitrous oxide was administered by the surgeon who sutured the laceration. A nurse monitored the child throughout the procedure. At the end of the procedure, pain scores were evaluated by the surgeon and nurse using the FLACC (face, legs, activity, cry, and consolability) scale, a structured observational-behavioral scale for measurement of pain.

RESULTS

Sixty patients between the ages of 1 and 16 years participated in the study. Of these, 15 were sutured using standard care (lidocaine infiltration), and 45 children received nitrous oxide in addition to lidocaine infiltration. Nitrous oxide was administered for an average of 11.9 +/- 5.1 minutes (range, 4 to 30 minutes). Forty-three children recovered to preprocedure activity in less than 1 minute. Two children recovered in less than 3 minutes. Average FLACC scores during infiltration and suturing were significantly lower in the nitrous oxide group compared with controls (infiltration, 1.9 of 10 versus 9.7 of 10; suturing, 2 of 10 versus 8.8 of 10). Forceful restraining was necessary in all the controls, whereas in the nitrous oxide group mild force was required in only 15 percent. Seventy percent of the children receiving nitrous oxide had no side effects. Vomiting and nausea were the most common (17 percent), transient side effects. No respiratory or cardiovascular side effects occurred.

CONCLUSIONS

Nitrous oxide can be safely administered by plastic surgeons while suturing facial lacerations in the emergency room. The fast onset and rapid recovery characteristics of nitrous oxide provide a convenient environment for performing short surgical procedures. This safe method for provision of analgesia and anxiolysis may be appealing to plastic surgeons for ambulatory procedures (e.g., suture removal, expander inflation, Botox injection, injection of various fillers) in pediatric and adult populations.

The Use of Video Capture Virtual Reality in Burn Rehabilitation: The Possibilities

We independently explored the use of the Sony PlayStation II EyeToy (Sony Corporation, Foster City, CA) as a tool for use in the rehabilitation of patients with severe burns. Intensive occupational and physical therapy is crucial in minimizing and preventing long-term disability for the burn patient; however, the therapist faces a difficult challenge combating the agonizing pain experienced by the patient during therapy. The Sony PlayStation II EyeToy is a projected, video-capture system that, although initially developed as a gaming environment for children, may be a useful application in a rehabilitative context. As compared with other virtual reality systems the EyeToy is an efficient rehabilitation tool that is sold commercially at a relatively low cost. This report presents the potential advantages for use of the EyeToy as an innovative rehabilitative tool with mitigating effects on pain in burn rehabilitation. This new technology represents a challenging and motivating way for the patient to immerse himself or herself in an alternate reality while undergoing treatment, thereby reducing the pain and discomfort he or she experiences. This simple, affordable technique may prove to heighten the level of patient cooperation and therefore speed the process of rehabilitation and return of functional ability.

Treatment of deep sternal wound infections post-open heart surgery by application of activated macrophage suspension

Postoperative sternal wound infection remains a significant complication and generally causes considerable morbidity and mortality. Macrophages play a major role in the process of wound healing. In order to evaluate the efficacy of local injection of activated macrophage suspensions into open infected sternal wound space, a retrospective case-control study was conducted. Sixty-six patients with deep sternal wound infection treated by activated macrophages (group 1) and 64 patients with deep sternal wound infection treated by sternal reconstruction surgery with various regional flaps (group 2), were matched for gender, age, and risk index. In up to 54 months of follow-up of group 1, 60 patients (91%) achieved complete wound closure. Two (3%) late deaths occurred unrelated to the procedure. Mortality rate in group 2 was 29.7% (19/64). Duration of hospitalization was 22.6 days in group 1 vs. 56.2 days in group 2. Patients with deep sternal wound infection following open heart surgery that were treated by activated macrophages had significantly less mortality as well as significant reduction of hospitalization in comparison to the surgically treated group. These results illustrate the advantages of using a biologically based activated macrophage treatment.

Targeting small-cell lung cancer with novel fluorescent analogs of somatostatin

Early, accurate detection of small-cell lung cancer (SCLC), before it becomes systemic, is essential for successful treatment. Fluorescence-based imaging provides safe, sensitive detection of malignancies. Targeted delivery of fluorophores increases sensitivity of endoscopic imaging. We synthesized novel somatostatin analogs, based on backbone cyclic peptides, and conjugated them with fluorescent agents. Nineteen conjugates differing in core peptide, length of alkyl linker and fluorescence moiety (rhodamine and fluorescein) were tested in vitro, using a receptor binding assay, and nine of the more promising conjugates were tested in vivo by fiber-optic spectrofluorimetry and quantitative spectral imaging, on an H69 human SCLC tumor mouse xenograft model. The lead compound showed exceptional tumor/normal tissue ratios, ranging from 9 to 90, and has potential for targeting SCLC overexpressing somatostatin receptors.

Competitive quenching: a possible novel approach in protecting RPE cells from damage during PDT

PURPOSE

The purpose of this study is to demonstrate feasibility of using our novel concept, termed competitive quenching, for protecting the choroidal extravascular compartment and retinal pigment epithelium (RPE) from verteporfin (VP)-induced phototoxicity using hypericin. Furthermore, we aim to achieve partitioning of the quencher, hypericin, in the extravascular space and VP within the microvascular compartment of the chorio-retinal complex in vivo.

METHODS

We protect RPE cells from damage inflicted by photoactivated VP by introducing hypericin into these cells prior to photosensitization to quench the photosensitizing activity of VP. Cell protection levels were measured by MTT and Hemacolor viability assays. Wavelength range used for VP photoexcitation (700 +/- 40 nm) excludes the absorption range of hypericin, preventing the latter from photoactivation. Pharmacokinetic conditions, in which hypericin spreads throughout the choroidal and retinal extravascular space while VP is confined to the vasculature, are delineated using double-fluorescence imaging.

RESULTS

Cell viability increased 3- to 5-fold when 10-20 microM hypericin were present in RPE cells during photosensitization with 0.1-0.5 microM VP. VP fluorescence intensity was unchanged by the presence of hypericin in the cells. Hypericin administered intravenously to rats was confined to the choroidal vasculature after 15 min to 2 hr. Subsequently, hypericin partitioned to the choroidal and retinal extravascular space. VP administered at this time was confined to the microvasculature.

CONCLUSIONS

RPE and choroid may potentially be protected by compartmentalizing hypericin to the extravascular compartment while VP administered shortly before photosensitization is confined to the microvasculature. Adverse photodynamic therapy (PDT) damage to choroidal tissues adjacent to neovasculature targeted for photoablation have the potential of being prevented by competitive quenching with hypericin.

Convection-Enhanced Drug Delivery: Increased Efficacy and Magnetic Resonance Image Monitoring

Convection-enhanced drug delivery (CED) is a novel approach to directly deliver drugs into brain tissue and brain tumors. It is based on delivering a continuous infusion of drugs via intracranial catheters, enabling convective distribution of high drug concentrations over large volumes of the target tissue while avoiding systemic toxicity. Efficient formation of convection depends on various physical and physiologic variables. Previous convection-based clinical trials showed significant diversity in the extent of convection among patients and drugs. Monitoring convection has proven to be an essential, yet difficult task. The current study describes the application of magnetic resonance imaging for immediate assessment of convection efficiency and early assessment of cytotoxic tissue response in a rat brain model. Immediate assessment of infusate distribution was obtained by mixing Gd-diethylenetriaminepentaacetic acid in the infusate prior to infusion. Early assessment of cytotoxic tissue response was obtained by subsequent diffusion-weighted magnetic resonance imaging. In addition, the latter imaging methodologies were used to establish the correlation between CED extent and infusate's viscosity. It was found that low-viscosity infusates tend to backflow along the catheter track, whereas high-viscosity infusates tend to form efficient convection. These results suggest that CED formation and extent may be significantly improved by increasing the infusate's viscosities, thus increasing treatment effects.

Burn care standards in Israel: lack of consensus

In recent years, the need for a national burn center based on ABA guidelines has emerged in Israel. The formation of such a center is now underway in the Chaim Sheba Medical Center. As a first step in the standardization of burn care in Israel, we have conducted a nation-wide survey among burn care personnel (physicians, nurses and other burn team members), regarding different aspects of the treatment of burn patients.

METHODS

A questionnaire comprised of 30 questions regarding the severity of burns admitted, the site of initial management, wound care (both burn/skin-graft sites and donor sites), dressing changes protocols, sterility precautions, hydrotherapy, and pressure dressings was presented to 70 health-care professionals involved in the treatment of burns.

RESULTS AND DISCUSSION

Seventy-seven percent of interviewed personnel participated in the survey. Consensus was found regarding most local (topical) wound care, (SSD for clean non-facial burns, Sulfamylon (mafenide-acetate) for contaminated non-facial burns, Threolone (chloramphenicol 3% and prednisolone 0.5%) or Bacitracin for facial burns, Paraffin gauzes with or without Sulfamylon for donor and graft sites). Dressing changes regimes were also agreed upon generally. However, there was no consensus regarding the ideal time for the removal of donor site dressings and this issue will need to be resolved. Other important findings are that both Edinborough University Solution of Lime (EUSOL), which has been deemed unsuitable for burn treatment due to toxic effects, and hydrotherapy, which has been proposed as a source of infection and contamination, are still widely used. We anticipate that these issues will be settled in our unified national burn care protocols (which are currently under development and revision).

Use of mitomycin C for treatment of keloid: a preliminary report

OBJECTIVES

Mitomycin C (MC) is an anti-neoplastic agent with an anti-proliferative effect on fibroblasts. We set out to evaluate the effect of MC application following keloid excision.

STUDY DESIGN AND SETTING

Patients with keloid in a tertiary referral center were enrolled in a prospective study. The scar was excised and prior to skin closure, a pledget with 1 cc of MC 0.4 mg/mL was applied for 5 minutes. Patient satisfaction and keloid thickness were assessed.

RESULTS

All patients were satisfied with the results, although complete disappearance of the keloid was evident only in two. Keloid thickness was measured and ranged from 5 to 26 mm. Following surgery and treatment at 2 months thickness ranged from 0 to 8 mm.

CONCLUSIONS

MC application following scar resection appears to be effective in treatment of keloid.

SIGNIFICANCE

As no specific effective treatment for keloid is currently available, utilization of this readily available therapeutic agent may improve treatment outcome.

Improved pharmacokinetics, biodistribution and necrosis in vivo using a new near infra-red photosensitizer: tetrahydroporphyrin tetratosylat

The search for better photosensitizers for photodynamic therapy of malignancies has led to the investigation of a new water-soluble, positively charged, and chemical stable tetrahydroporphyrin tetratosylat (THPTS) with a strong absorption at 760.5 nm, belonging to the bacteriochlorophyll family. THPTS undergoes a rapid uptake by human choroidal melanoma (CM) cells with a weak dark toxicity after a 24-h incubation (LD10 = 150 microM, LD50 = 6.0 mM). In response to laser light at 760+/-3 nm and doses of 10, 15 and 30 J/cm2, around 71%, 76%, and 92% of the CM cells were killed, respectively. Studies of pharmacokinetics and biodistribution in vivo (living mice) and ex vivo (excised organs) were made in a Balb/c mice bearing subcutaneously inoculated C26 colon carcinoma using fiber-optic spectrofluorimetry (FOS). Tumours were irradiated 3 h after intraperitoneal (i.p.) injection of 5.0 mg/kg THPTS with an incoherent light source at 750+/-20 nm and an intensity of 100 mW/cm2 and fluences of 60, 90 and 120 J/cm2. THPTS demonstrated preferential accumulation in C26 colon carcinoma in comparison with most normal tissues except kidneys. For the tissues of liver, colon, muscle, and spleen the tumour/normal tissue ratio (TNTR) ranged from 8.0 to 50. After irradiation with 120 J/cm2 the depth of tumour necrosis reached 15 mm. Histological examination of the tumour samples 24 h after THPTS-PDT, revealed severe stasis in the blood vessels and coagulative necrosis. These results suggest that THPTS-PDT may be of particular importance in the treatment of accessible malignancies.

Monitoring PDT-induced damage using spectrally resolved reflectance imaging of tissue oxygenation

Photodynamic therapy (PDT) with chlorin e6 (Chl) was monitored in vivo using vital microscopy and Fourier transform spectral imaging (FT-SI). Mammary C26 colon carcinoma, implanted intradermally in a mouse, was irradiated at 650 nm with various radiant exposures, 3 h after administration of 5 mg/kg Chl. The photodynamic response (PDR) in the skin flap with tumor was expressed as microcirculation disturbances (thrombi formation, multiple embolizations, arteriolar occlusion and venous stasis) and, dependent on the radiant exposure, was transient or permanent. These biological manifestations were accompanied by a change in hemoglobin (Hb)/oxyhemoglobin (HbO2) absorption spectra obtained in vivo by FT-SI. False-color mapping of hemoglobin oxygen saturation (OS) visualized the alteration of tissue oxygenation. The results demonstrate, for the first time, that FT-SI can serve as a sensitive non-invasive tool for OS monitoring of PDT effects.

Ten commandments for minimal pain during administration of local anesthetics

Local anesthetic agents are administered before many ambulatory cutaneous operations. The injection of the local anesthetic agent is often the only painful aspect of the procedure. There are various factors that determine how painful the anesthetic administration may be. These include the preparation used, the size of the needle and syringe used, injection technique, depth of injection, attitude of the physician, and more. In this article, we present the different techniques we apply to achieve minimal pain during the injection of local anesthetics.

[Ultrasonic apocrine suction-lipolysis under endoscopic guidance for axillary osmidrosis]

There are several modalities to treat axillary hyperhydrosis. None of these eliminates the sweat-associated odor (Osmidrosis), which is sometimes present even despite local hygiene and use of deodorants. A technique to dissolve the axillary apocrine glands under endoscopic guidance has been described to be highly efficient, without compensatory hyperhydrosis. We describe our experience with the first 18 patients who were treated by this technique. A 1.5 cm axillary incision was used to introduce both the endoscope and the ultrasonic suction-lipolysis device. Complete disappearance of axillary sweat and odor was achieved immediately after treatment. Superficial hematoma was the only complication encountered. One-sided recurrence was observed in one patient over an 8 month follow-up period.

Genetics in melanoma

Melanoma is the leading cause of death from skin tumors worldwide, with an annual increase in incidence over the past decade. The molecular mechanisms involved in melanoma pathogenesis are beginning to be unraveled. While a family history of melanoma and exposure to ultraviolet irradiation have been known for years as risk factors in melanoma development, the precise genes involved in inherited predisposition were defined only in the past decade. Germline mutations in two genes that play a pivotal role in controlling cell cycle and division--CDKN2A and cyclin-dependent kinase 4 (CDK4)--have been detected in autosomal, dominant, high penetrance familial melanoma cases. In addition to these two highly penetrant genes, germline mutations and polymorphisms in a few low penetrance genes have been reported in familial melanoma cases: melanocortin-1 receptor, epidermal growth factor, glutathione s-transferase M1, cytochrome p450 debrisoquine hydroxylase locus (CYP2D6) and vitamin D receptor.

Macrophage suspensions prepared from a blood unit for treatment of refractory human ulcers

This paper presents an innovative method for the treatment of refractory wounds, starting with a blood unit, that is based on a biological approach. Local wound repair is one of the major unresolved clinical problems. Age, infection, clinical conditions such as diabetes mellitus, cardiac, renal, lung and liver failure, malnutrition and immunological deficiencies are among the reasons for wound repair delay or failure. Many chronic ulcers resist conventional treatment and do not heal for months and years, thus causing substantial morbidity and even mortality. The method for macrophage suspension treatment consists of introducing into the wound live cells that play a major role in the process of wound healing. The suspension is prepared from a blood unit of a healthy donor in a cost-effective, closed, sterile system. In the process of preparation, the macrophages are activated by hypo-osmotic shock to enhance their various functions in wound repair. The cells are applied to the wound either by local injection or by direct deposition into the wound. In most cases (90%), only one treatment is sufficient. Since 1995, macrophage suspensions have been used successfully in more than 1000 patients in several hospitals in Israel, without any side effects. Our results show that the use of a macrophage suspension is a safe and effective therapeutic strategy that shortens the healing period, reduces risk of complications and morbidity and improves the quality of life for long-suffering patients. This treatment requires no hospitalization and can be given on an ambulatory basis.

Pretreatment prediction of brain tumors' response to radiation therapy using high b-value diffusion-weighted MRI

Diffusion-weighted magnetic resonance imaging (DWMRI) is sensitive to tissues' biophysical characteristics, including apparent diffusion coefficients (ADCs) and volume fractions of water in different populations. In this work, we evaluate the clinical efficacy of DWMRI and high diffusion-weighted magnetic resonance imaging (HDWMRI), acquired up to b = 4000 sec/mm(2) to amplify sensitivity to water diffusion properties, in pretreatment prediction of brain tumors' response to radiotherapy. Twelve patients with 20 brain lesions were studied. Six ring-enhancing lesions were excluded due to their distinct diffusion characteristics. Conventional and DWMRI were acquired on a 0.5-T MRI. Response to therapy was determined from relative changes in tumor volumes calculated from contrast-enhanced T1-weighted MRI, acquired before and a mean of 46 days after beginning therapy. ADCs and a diffusion index, R(D), reflecting tissue viability based on water diffusion were calculated from DWMRIs. Pretreatment values of ADC and R(D) were found to correlate significantly with later tumor response/nonresponse (r = 0.76, P <.002 and r = 0.77, P <.001). This correlation implies that tumors with low pretreatment diffusion values, indicating high viability, will respond better to radiotherapy than tumors with high diffusion values, indicating necrosis. These results demonstrate the feasibility of using DWMRI for pretreatment prediction of response to therapy in patients with brain tumors undergoing radiotherapy.

Antimetastatic activity of the photodynamic agent hypericin in the dark

A unique property of the photodynamic signal transduction inhibitor hypericin (HY) is high functionality in the dark, which has been shown to result in portfolio of anticancer activities both in vitro and in vivo. Here we show that treatment with HY significantly reduces growth rate of metastases in 2 murine models: breast adenocarcinoma (DA3) and squamous cell carcinoma (SQ2). Focus on metastases was achieved by resection of primary tumors at stages in which micrometastases exist in lungs. Long-term animal survival in DA3 tumor-excised groups increased from 15.6% in controls to 34.5% following supplementary treatment with HY. In mice bearing SQ2 tumor metastases, therapy with HY increased animal survival from 17.7% in controls to 46.1%. Using Laser-induced fluorescence and multipixel spectral image analyses, we demonstrate that HY has a high tendency to accumulate in primary and metastatic tumors; HY content in lungs bearing metastases was approximately 2-fold higher than in the lungs of healthy animals. The tendency of HY to preferentially concentrate in lung metastases, combined with its potent antiproliferative activities, may render HY as a useful supplementary modality in the treatment of metastatic cancer irrespective of photoactivation.

[Sex reassignment surgery]

Israel is among the few countries in the world where sex reassignment surgery (SRS) is performed in public hospitals. Today, the only center performing SRS in Israel is the Sheba Medical Center. A multidisciplinary committee grants authorization permitting surgery after a follow-up period of two years. We found that this multidisciplinary approach leads to the best therapeutic results. We briefly present the pre-operative evaluation, operative approach, post-operative course, final results and complications of sex reassignment surgery. This article aims to inform physicians of this therapeutic option, and the indications for referral.

High-b-value diffusion-weighted MR imaging for pretreatment prediction and early monitoring of tumor response to therapy in mice

PURPOSE

To evaluate the use of diffusion-weighted magnetic resonance (MR) imaging with standard and high b values for pretreatment prediction and early detection of tumor response to various antineoplastic therapies in an animal model.

MATERIALS AND METHODS

Mice bearing C26 colon carcinoma tumors were treated with doxorubicin (n = 25) and with aminolevulinic acid-based photodynamic therapy (n = 23). Fourteen mice served as controls. Conventional T2-weighted fast spin-echo and diffusion-weighted MR images were acquired once before therapy and at 6, 24, and 48 hours after treatment. Pretreatment and early (1-2 days) posttreatment water diffusion parameters were calculated and compared with later changes in tumor volumes measured on conventional MR images by using the Pearson correlation test.

RESULTS

In chemotherapy-treated tumors, a significant correlation (P <.002, r = 0.6) was observed between diffusion parameters that reflected tumor viability, measured prior to treatment, and changes in tumor volumes after therapy. This correlation implies that tumors with high pretreatment viability will respond better to chemotherapy than more necrotic tumors. In tumors treated with photodynamic therapy, no such correlation was found. Changes observed in water diffusion 1-2 days after treatment significantly correlated with later tumor growth rate for both therapies (P <.002, r = 0.54 for photodynamic therapy; P <.0003, r = 0.61 for chemotherapy).

CONCLUSION

High-b-value diffusion-weighted MR imaging has potential use for the early detection of response to therapy and for predicting treatment outcome prior to initiation of chemotherapy.

Parry-Romberg syndrome and sympathectomy--a coincidence?

Parry-Romberg syndrome is a clinical entity consisting of progressive hemifacial atrophy appearing at a young age. Animal studies indicate that sympathectomy can produce hemifacial atrophy. To our knowledge, this is the first report of a patient with a possible association between Parry-Romberg syndrome and thoracoscopic sympathectomy.