Treatment Of Large Lesions Research Articles

An experimental study to characterise the role of multihole nozzle in adjuvant assisted cryospray

Cryospray is a process of skin cancer treatment in which liquid nitrogen is sprayed on the lesion to achieve necrosis. In order to achieve necrosis through cryospray, a combination of particular cooling rate and lethal temperature is required. The small aperture of single hole nozzle (SHN) and the less mass flow rate associated with it reduce the rate of heat transfer from the lesion. Moreover, the low thermal conductivity of lesion further reduces the rate of energy diffusion inside it. These limitations associated with the existing method of cryospray fail to provide complete necrosis in the lesions of size larger than 15 mm in diameter. The present study addresses these issues through the modification in the existing spraying technique, i.e. inclusion of multihole nozzle (MHN) in cryospray and administration of Magnesium Oxide (MgO) nanoparticles as an adjuvant in the lesion to increase its rate of energy diffusion. The influence of mass flow rate and the rate of evaporation of cryogen on cryoablation are analysed experimentally while changing the geometrical parameters of 6 MHNs. To quantify the necrosis, thermocouples and FLIR thermal imaging camera are used to ascertain temperature profile below and above the gel surface respectively. The crystalline nature of nanoparticles is confirmed through TEM and XRD results with a particle diameter ranging between 10 and 40 nm. A comparative study of cryoablation is carried out between nano-phantom and normal-phantom. An increase of 59%, 96% and 64% in the area of necrotic zone is observed on the surface of nano-phantom for MHNs with 5 holes and margin of 1 mm, 1.5 mm and 2 mm respectively. The radius of interacellular ice formation has increased by 5 mm at an axial depth of 2 mm for MHNs with 5 holes in the nano-phantom than that in normal-phantom due to the increase in cooling rate. It is also observed that nano-phantom achieves a lower end temperature than the normal-phantom at every thermocouple position. Among the 6 MHNs selected for the study, MHN with 5 holes and 1.5 mm margin provides the most optimised result with the ablation zone of 42 mm on the surface of gel. Thus, it can be concluded that because of the introduction of adjuvant and modification in spraying device, cryoablation outcomes have been improved both quantitatively and qualitatively. The proposed approach will increase the scope of cryospray in the treatment of larger lesions.

Nano-cryospray: An adjuvant assisted approach to increase the efficacy of cryospray

The present study proposes a novel approach to treat skin cancer. It is an amalgamation of two techniques; (i) Cryospray in which necrosis is achieved through local application of liquid nitrogen spray on lesions (occurring on superficial skin) and (ii) Transdermal Drug Delivery systems (TDDS) in which drugs are administered through the superficial skin. It focuses on increasing the cryoablation through the administration of nanoparticles in the skin. Biodegradable Magnesium Oxide (MgO) nanoparticles are selected to make nano-phantom. TEM and XRD results reveal the crystalline nature of MgO nanoparticle with particle diameter 10–40 nm. A comparative study of cryoablation is carried out between the nano-phantom and the normal-phantom while spraying liquid nitrogen through a commercial 0.8 mm diameter single hole nozzle. Quantitative and qualitative improvements in cryoablation are observed due to the presence of nanoparticle. Necrotic zone in nano-phantom is twice larger than in the normal-phantom up to an axial depth of 2 mm from the centre of spray for the same spraying distance. Minimum spraying distance for nano-phantom is estimated to be 13 mm. Among the three spraying distances selected for the study, it has been observed that cryoablation decreases as the spraying distance increases. The proposed approach can be used to enhance the scope of cryospray in the treatment of larger lesions like Squamous cell carcinoma, keloids etc. without incorporating the device modifications.

Devices, techniques, traction, suturing, and countermeasures for endoscopic submucosal dissection complications

Endoscopic submucosal dissection (ESD) is widely performed to treat superficial colorectal tumors because it enables en bloc resection of various types of lesions. However, ESD sometimes leads to deleterious adverse events, such as perforation and delayed bleeding. Therefore, determining the precise preoperative indication for ESD is vitally important. Furthermore, small lesions with fibrosis and semi-large lesions can be managed using underwater endoscopic mucosal resection, and the “true” indication for ESD is for the treatment of larger lesions, for which ESD carries a higher risk. Here, we reviewed the devices, techniques (i.e., pocket creation method, water pressure method, and clip and flap method), traction (i.e., clip with line, pulley method, and clip with ring), suturing (i.e., line-assisted complete closure, loop clip, clip-on-clip closure method, mucosal incision around the mucosal defect, and hand-suturing), and countermeasures to address complications (i.e., bleeding after ESD, perforation, and post-ESD coagulation syndrome) that facilitate easier and safer ESD.

Hair Follicle as a Source of Pigment-Producing Cells for Treatment of Vitiligo: An Alternative to Epidermis?

To discuss the advantages and limitations of hair follicle-derived cell transplantation (FCT) in vitiligo, compared to the epidermal cell transplantation (ECT), and the knowledge gap which is required to be bridged. The papers relevant to the purpose was reviewed. Surgical approaches for treating vitiligo are based on the idea of replenishing lost melanocytes. Skin and hair follicles as the main sources of melanocytes have been applied for this purpose transferring the whole tissue or tissue-derived cell suspension to the vitiligo lesions. Considering the differences between hair follicle and epidermis in terms of the constituting cell populations, phenotype and function of melanocytes, and micro-environmental factors, different response of vitiligo patients to treatment with FCT or ECT would be expected theoretically. However, there is currently a lack of evidence on such a difference. However, ECT appears to be a more feasible, less time-consuming, and more comfortable treatment for both physicians and patients. Although the current evidence has not shown a significant difference between ECT and FCT in terms of efficacy, ECT appears to be more feasible specifically in the treatment of large lesions. However, further randomized controlled clinical trials with larger sample sizes and longer follow-up durations are required to be conducted to draw a definite conclusion on comparing FCT with ECT in terms of the safety, efficacy, durability of the therapeutic effects, and indications in vitiligo patients.

Stereotactic radiofrequency ablation of a variety of liver masses in children

Background and aims Surgical resection is currently the cornerstone of liver tumor treatment in children. In adults radiofrequency ablation (RFA) is an established minimally invasive treatment option for small focal liver tumors. Multiprobe stereotactic RFA (SRFA) with intraoperative image fusion to confirm ablation margins allows treatment for large lesions. We describe our experience with SRFA in children with liver masses. Methods SRFA was performed in 10 patients with a median age of 14 years (range 0.5–17.0 years) suffering from liver adenoma (n = 3), hepatocellular carcinoma (n = 1), hepatoblastoma (n = 2), myofibroblastic tumor (n = 1), hepatic metastases of extrahepatic tumors (n = 2) and infiltrative hepatic cysts associated with alveolar echinococcosis (n = 1). Overall, 15 lesions with a mean lesion size of 2.6 cm (range 0.7–9.5 cm) were treated in 11 sessions. Results The technical success rate was 100%, as was the survival rate. No transient adverse effects higher than grade II (Clavien and Dindo) were encountered after interventions. The median hospital stay was 5 d (range 2–33 d). In two patients who subsequently underwent transplant hepatectomy complete ablation was histologically confirmed. Follow-up imaging studies (median 55 months, range 18–129 months) revealed no local or distant recurrence of disease in any patient. Conclusions SRFA is an effective minimal-invasive treatment option in pediatric patients with liver tumors of different etiologies.

Percutaneous Ablation for Hepatocellular Carcinoma.

The purpose of this article is to discuss the use, comparative efficacy, and general technical considerations of percutaneous ablation, alone or in combination with other therapies, for the treatment of hepatocellular carcinoma (HCC). Percutaneous ablation is a mainstay treatment for early-stage HCC, offering survival comparable to that of surgical resection for small lesions. It can act as a primary curative therapy or bridge therapy for patients waiting to undergo liver transplant. New ablation modalities and combining tumor ablation with other therapies, such as transarterial chemoembolization, can improve clinical outcomes and allow treatment of larger lesions. Combining thermal ablation with systemic chemotherapy, including immunotherapy, is an area of future development.

Arthroscopic Surgical Technique for an Acute Talar Dome Osteochondral Lesion in a Professional Rugby League Player

Talar osteochondral lesions represent challenging clinical entities, particularly in high-demand athletes. Surgical treatment of large lesions often requires a 2-step procedure, or the use of osteotomy in the case of autologous osteochondral transfer, which can delay return to sport. A professional rugby league player underwent surgery for a complex injury to the ankle. A talar osteochondral lesion with a maximal diameter of 15 mm was treated in an arthroscopic fashion using the cartilage taken from the completely displaced osteochondral fragment. Cartilage was cut into chips and combined with bone graft product containing platelet-derived growth factor and a porous collagen scaffold. Autologous cartilage was then reimplanted arthroscopically. The patient was allowed full ankle motion from 2 weeks postoperatively, and weightbearing was commenced at 6 weeks. Follow-up imaging and functional outcomes, including return to sport, were assessed at regular intervals. The patient was able to return to professional rugby league by 23 weeks postoperatively. Magnetic resonance imaging at 16 months postoperatively showed restoration of the subchondral plate and osseous infill. At final follow-up, the patient remained pain free and was playing at preinjury level. This report describes good outcomes using a novel, 1-step cartilage repair technique to treat a large talar osteochondral lesion in a professional athlete. Level V: Expert opinion.

Trattamento dell’osteocondrite dissecante del ginocchio con scaffold osteocondrale biomimetico

The aim of this study was to evaluate the potential of a biomimetic osteochondral scaffold for the treatment of osteochondritis dissecans (OCD). Twenty-seven consecutive patients, affected by knee OCD, were treated with the implantation of an acellular collagen-hydroxyapatite scaffold and prospectively evaluated at 4 years of follow-up. A significant improvement in all clinical scores was obtained at up to the final follow-up. This osteochondral scaffold is a valid option for knee OCD, showing a good and durable clinical outcome even for the treatment of large lesions.

The optimization of treatment planning and ablation rate improvements on feasibility of pediatric MR-HIFU applications

Magnetic resonance-guided high intensity focused ultrasound (MR-HIFU) ablation provides a precise, non-invasive treatment for lesions in adults. In children, MR-HIFU’s potential remains largely unexplored, though its non-invasive and non-ionizing nature holds promise. Yet, pediatric patients pose challenges affecting treatment: young children require general anesthesia, exhibit wide ranges of anatomy, and have varying lesion sizes and locations. These demonstrate a need for standardized treatment approaches and physical aids to optimize patient position, reduce time-intensive repositioning, and thus reduce overall treatment time. Further improvement of ablation rate and reduction of risk are also possible via improved monitoring of skin temperature during ablation and mild hyperthermia. Improvements in treatment planning and volumetric rate may save time and allow for treatment of larger lesions, increase patient throughput, and possibly increase efficacy and lower cost. This study aims to quantify and examine how such improvements could increase the time allocated for direct ablation and produce better outcomes.

Microwave ablation of hepatocellular carcinoma.

Although surgical resection is still the optimal treatment option for early-stage hepatocellular carcinoma (HCC) in patients with well compensated cirrhosis, thermal ablation techniques provide a valid non-surgical treatment alternative, thanks to their minimal invasiveness, excellent tolerability and safety profile, proven efficacy in local disease control, virtually unlimited repeatability and cost-effectiveness. Different energy sources are currently employed in clinics as physical agents for percutaneous or intra-surgical thermal ablation of HCC nodules. Among them, radiofrequency (RF) currents are the most used, while microwave ablations (MWA) are becoming increasingly popular. Starting from the 90s', RF ablation (RFA) rapidly became the standard of care in ablation, especially in the treatment of small HCC nodules; however, RFA exhibits substantial performance limitations in the treatment of large lesions and/or tumors located near major heat sinks. MWA, first introduced in the Far Eastern clinical practice in the 80s', showing promising results but also severe limitations in the controllability of the emitted field and in the high amount of power employed for the ablation of large tumors, resulting in a poor coagulative performance and a relatively high complication rate, nowadays shows better results both in terms of treatment controllability and of overall coagulative performance, thanks to the improvement of technology. In this review we provide an extensive and detailed overview of the key physical and technical aspects of MWA and of the currently available systems, and we want to discuss the most relevant published data on MWA treatments of HCC nodules in regard to clinical results and to the type and rate of complications, both in absolute terms and in comparison with RFA.

Intraosseous pseudotumour of the talus in a child with severe haemophilia

We report a case of a large pseudotumour in the right talus of an 11-year-old boy with severe haemophilia A. The described intraosseous lesion was treated with surgical curettage and autologous bone grafting. Twenty months postoperatively computed tomography scan showed no signs of recurrence. Forty months postoperatively radiological studies confirmed satisfactory incorporation of the graft, no evidence of bone growth disturbance and improvement of Pettersson score of the ankle joint. At the same time, regarding his clinical situation, he was able to fully participate in his daily activities, presenting painless and almost full range of motion of his right ankle joint. Surgical intervention seems to be the best option in treating a big pseudotumour of the talus during childhood. As conservative management in the treatment of large lesions may fail, disastrous complications like a pathological fracture may happen. Anatomical reconstruction of a talus when pseudotumour and pathological fracture coexist is a major challenge for an orthopaedic surgeon.

Investigation of intracranial peripheral dose arising from the treatment of large lesions with Leksell GammaKnife®Perfexion™

This investigation involves quantifying the extent of intracranial peripheral dose arising from simulated targets situated in the skull-base or upper-spine region using the Leksell GammaKnife Perfexion treatment unit. For each of three spherical target volumes--denoted as Vs (4 cm3), VM (18 cm3), and VL (60 cm3)--three treatment plans were manually generated, one for each of the three collimator sizes--4, 8, and 16 mm. Each of the plans was delivered to a spherical dosimetry phantom with an insert containing EBT Gafchromic film. The total dose at 70 mm from the targets' edges, %D(70 mm), was measured as a function of elevation angle and expressed as a percentage of the prescription dose. The film insert was placed centered in the median sagittal plane (Leksell X = 100) and %D(70 mm) was measured for the angular range from 0 degree (superior/along Z axis) to 90 degrees (anterior/along Y axis). For a given collimator i, the irradiation time ti to treat a spherical target of volume V using the 50% isodose line was observed to follow a power-law relationship of the form ti = Ai(V/ Vi)n where Ai was the maximum dose divided by collimator dose rate and Vi was the volume encompassed by the 50% isodose line for a single shot. The mean value of n was 0.61 (range: 0.61-0.62). Along the superior (Z) direction (angle=0 degree) and up to angles of around 30 degrees, the %D(70 mm) was always highest for the 4 mm plans, followed by the 8 mm, followed by the 16 mm. In this angular range, the maximum measured %D(70 mm) was 1.7% of the prescription dose. The intracranial peripheral dose along the superior direction (combined scatter and leakage dose) resulting from irradiation of upper-spine or base-of-skull lesions is measured to be less than 2% of the prescription dose, even for very large (60 cm3) targets. The results of this study indicate that, for a given target volume, treatment plans consisting of only 4 mm shots yield larger peripheral dose in the superior direction than 8 mm shot only plans, which in turn yield larger peripheral dose than 16 mm shot only plans.

Lentigo Maligna—Outcomes of Treatment with Q-Switched Nd:YAG and Alexandrite Lasers

Surgical excision is considered the criterion standard treatment for lentigo maligna (LM) but may sometimes be unsuitable for elderly people or in the treatment of large lesions. To evaluate the role of Q-switched neodymium-doped yttrium aluminium garnet (QS:Nd:YAG) and alexandrite lasers in the treatment of LM. QS:NdYAG and alexandrite lasers were used to treat histologically proven LM in 22 patients who were considered unsuitable for wide surgical excision or declined it. Patients were assessed at 6-month intervals for a maximum period of 5 years. Complete clinical response was achieved in 12 patients after one to four treatments and a follow-up of 2 to 5 years after last treatment. Excellent cosmesis was achieved in all patients. LM melanoma developed in two lesions, which were subsequently excised. Recurrence occurred in four patients. Although QS:Nd:YAG and alexandrite laser treatment of LM produced long-term clearance in 12 of the 22 patients, the ease and speed of this treatment and excellent cosmetic outcome achieved make this a suitable alternative to surgical excision, especially in elderly people, in treatment of large lesions, or in patients who refuse surgical treatment.

Teratoid Cyst of Floor of the Mouth: A Clinicopathologic Study of 20 Chinese Patients

The aim of this study is to document the clinicopathologic features of teratoid cyst of the floor of the mouth in 20 Chinese patients, who were treated in Wuhan University. The 20 teratoid cysts were analyzed. All cases were confirmed by pathology. English literature was also reviewed. Our investigations showed that both sexes were equal to have these cysts. The age at diagnosis ranged from 25 days to 34 years, and the greatest frequency was within the first decade. It was found that the congenital cysts were most commonly diagnosed in the midline. All cases were treated by cystectomy, using 1 of the 2 approaches: extraoral or intraoral. Whenever, combined approaches were used in 2 cases. In all, 16 patients were followed-up, and 2 patients had recurrences. The intraoral approach was also effective for the treatment of large lesions and led to very good cosmetic and functional results.

005������Topical photodynamic therapy in dermatology ��� 3 years experience at Beaumont Hospital

Topical photodynamic therapy (PDT) involves selective photosensitization of a target tissue by means of a topical agent, which is then activated by light to effect an oxygen dependent cytotoxic reaction. Premalignant and malignant skin conditions including actinic keratosis, squamous cell carcinoma in situ (Bowen's disease), and superficial basal cell carcinoma (BCC) have been effectively treated with PDT. A number of studies support the use of topical PDT in the treatment of acne, warts, psoriasis and T-cell lymphoma. There are many case reports and small series, with varying results, in a wide variety of other non-malignant applications. We report our experience of topical PDT over a 3 year period. We selected patients to participate in an open study of ALA-PDT on the basis of failure of, or unsuitability for conventional therapy. One hundred and ten patients participated in the study, with a mean age of 73 years. One hundred and twenty-nine lesions were treated, which consisted of 95 lesions of Bowen's disease, 21 superficial BCC's, nine patients with multiple actinic keratosis and four with porokeratosis. Patients were assessed at 3, 6 and 12 month intervals. Clearance and recurrence rules, adverse events and patient preference (where lesions had been treated previously) were recorded, Clearance rates for actinic keratosis, Bowen's disease and BCC were 87.5%, 84%, and 57%, respectively. Seventy-four percent of patients had a single treatment. Fourteen percent had two, and the remainder had up to four treatements in total. Though topical PDT has not proven to be superior to conventional methods, it is well tolerated with excellent cosmetic results. It is of particular value in the treatment of large lesions, in those with poorly vascularised skin, and in areas of diffuse actinic damage. Careful patient selection, prior debulking of lesions, and newer more selective agents with enhanced penetration, promise to further improve outcome.

Human papillomavirus infection and the size and grade of cervical intraepithelial neoplastic lesions associated with failure of therapy

OBJECTIVE: This investigation was designed to identify specific risk factors associated with treatment failure for cervical intraepithelial neoplasia. METHOD: A cohort of 436 women was assessed for the presence of co-factors associated with therapy failure. The risk factors included the HP V infection status of the patient, a previous history of genital condyloma and the size of cervical lesions. RESULT: The treatment outcome was not related to the treatment modality (P = 0.058). Thirteen (8.1%) women failed laser therapy while 15 (5.4%) women failed cryotherapy. While treatment failure occurred only in the presence of HP V infection (P = 0.036), failure was not related to infection by a specific genotype. Therapy failure was associated with treatment for CIN II (RR 4.157) and CIN III (RR 2.053) relative to CIN I and treatment of large lesions (P = 0.014). CONCLUSION: The determination of the relative area occupied by cervical lesions may have prognostic value in identifying women who are at risk for treatment failure.

Role of the Gamma Knife in the treatment of large lesions.

A virtual reality dose planning system, DosePlan(R), has been devised to increase the speed and accuracy of multishot dose planning for larger lesions treated in the Leksell Gamma Knife. The accuracy of the dose-planning was sophisticated further by a number of additional quality assurance procedures during the radiological definition of the target. Some aspects of the experience in Chicago are described in respect to the first 600 patients treated in the Gamma Knife. Only 35.4% had a maximum diameter of 35 mm or less. The size of the lesions required multiple-shot dose plans, with an average of 8.9 shots per patient and a tendency to an increasing number of shots with increasing experience. Some specific cases are illustrated to show the effectiveness of the dose-planning methods described.

Variables associated with the development of complications from radiosurgery of intracranial tumors

Between 5/21/86 and 11/1/89, we treated 64 recurrent or inoperable intracranial tumors in 60 patients (40 primary, 24 metastatic) with stereotactic radiosurgery using a modified 6 MeV linear accelerator at the Joint Center for Radiation Therapy. Patients were followed until death or 1/1/90. The median follow-up was 8 months (2–43 months). Fourteen patients experienced complications from 12 hours to 7 months (median 3 months, but only two patients more than 4 months) following radiosurgery. To determine variables related to complication, we calculated integral dose-volume histograms for 61 64 lesions and the surrounding CT-defined normal tissue. We excluded 16 lesions in 15 patients for follow-up < 4 months (12 patients) or insufficient treatment information (3 patients). The variables for which higher values were associated with significantly more toxicity in a univariate score test were: a) tumor dose inhomogeneity ( p < 0.00001), b) maximum tumor dose ( p = 0.00002), c) number of isocenters ( p = 0.00002), d) maximum normal tissue dose ( p = 0.00005) and e) tumor volume ( p = 0.0001). These variables were all highly correlated with tumor dose inhomogeneity (coefficients of rank correlation 0.75 -0.81). Tumor dose inhomogeneity had a much higher loglikelihood in a logistic model than any other single variable and a higher loglikelihood than any other two variables combined. None of the 21 patients with metastatic lesions experienced a complication. When we excluded the metastatic lesions, the above five variables remained significant in univariate tests. The mean tumor dose, number of treatment arcs, total degrees of arc, tumor location, previous radiotherapy, tumor geometry, pretreatment performance status, collimator size, and age were not significantly associated with toxicity. We conclude that radiosurgery of intracranial tumors is associated with a low risk of complications for lesions < 10cc treated with a single isocenter to maximum tumor doses < 25 Gy with tumor dose inhomogeneity < 10 Gy, but that treatment of larger lesions will require new treatment strategies which reduce the tumor dose inhomogeneity associated with multiple isocenter treatments.