N.W.J. Kelleners-Smeets

Photodynamic Therapy in Bowen's Disease: Influence of Histological Features and Clinical Characteristics on Its Success

Background: In Bowens disease (BD) there is no consensus on optimal treatment. Photodynamic therapy (PDT) is an effective non-invasive treatment modality for BD with excellent cosmetic results. Objective: This retrospective study examines whether clinical and histological features of BD impact PDT response. Methods: Patients with previously untreated BD from 2002 until 2007 were identified at the Maastricht University Medical Centre. Patients treated with PDT were included. All histological slides were re-examined. Results: During the study period 98 tumours were treated with PDT. In univariate analysis severe atypia and higher age were associated with decreased probability of clinical clearance. Higher age was also associated with an increased risk of recurrence. In multivariate analysis severe atypia remained the only independent risk factor for therapy failure. Conclusion: In patients with BD, severe atypia and higher age are associated with an increased risk of treatment failure after PDT.

Correlation Between Histological Findings on Punch Biopsy Specimens and Subsequent Excision Specimens in Cutaneous Squamous Cell Carcinoma

Diagnosis and subsequent treatment of cutaneous squamous cell carcinoma are frequently based on punch biopsies. Regarding the current TNM classification and stage grouping for cutaneous squamous cell carcinoma, it is important to identify the high-risk features (infiltration depth >u20094 mm, perineural and/or lymphovascular invasion and poor differentiation). This study investigates the agreement of histological high-risk features and TNM grouping stage on 3 mm punch biopsies and subsequent surgical excision in 105 patients diagnosed with cutaneous squamous cell carcinoma. On punch biopsy, infiltration depth >u20094 mm is not identified in 83.3% (30/36), perineural invasion in 90.9% (10/11) and poor differentiation in 85.7% (6/7) of cases. The TNM stage was underestimated on punch biopsy in 15.4% (16/104). This study shows that on a 3 mm punch biopsy, high-risk features in cSCC can remain undetected and that the actual TNM stage is not identified in 1 out of 6 tumours.

Bowen's Disease: A Six-year Retrospective Study of Treatment with Emphasis on Resection Margins

Bowens disease is an in situ squamous cell carcinoma of the skin with various treatment modalities available. A major advantage of surgical excision is the opportunity to histologically examine the resection margins. There is no consensus about the most appropriate margin. This retrospective study evaluates the clearance rates achieved by excision with a 5 mm margin and estimates how that might change after fictitiously reducing the resection margin by 1 or 2 mm. Patients with histologically confirmed Bowens disease were selected at the Maastricht University Medical Centre from 2002 until 2007. Surgical margins and complete excision rates were evaluated and histological slides were re-examined. To our knowledge this is the first study investigating the safety margin for Bowens disease. As Bowens disease is not an invasive disease, minimisation of healthy tissue excision is desirable. Our data show that a hypothetical reduction of the safety margin from 5 mm to 4 or 3 mm decreases the complete excision rate from 94.4% to 87% and 74.1%, respectively.

Treatment of superficial basal cell carcinoma by topical photodynamic therapy with fractionated 5-aminolaevulinic acid 20% vs. two-stage topical methyl aminolaevulinate: results of a randomized controlled trial

Basal cell carcinoma (BCC) is the most common type of skin cancer and incidence rates are increasing. Photodynamic therapy (PDT) is a frequently used treatment, especially for superficial BCC (sBCC). Two topical photosensitizing agents are currently used to treat sBCC, namely 5‐aminolaevulinic acid (ALA) and its ester, methyl aminolaevulinate (MAL). Previous research showed a high efficacy for ALA‐PDT using a twofold fractionated illumination scheme in which two light fractions of 20 J cm−2 and 80 J cm−2 were delivered 4 h and 6 h after ALA application.

Risk Factors for Surgical Site Infections in Dermatological Surgery

Current literature on risk factors for surgical site infection (SSI) in dermatological surgery in the absence of antibiotic prophylaxis is limited. The aim of this study was to retrospectively evaluate patients presenting for dermatological surgery. A total of 1,977 procedures were reviewed. SSI was clinically suspected in 79 (4.0%) patients and confirmed by culture in 38 (1.9%). Using the strictest definition of SSI (clinical symptoms with positive culture) significantly higher risk of SSI was found for location on the ear (odds ratio (OR) 6.03, 95% confidence interval (95% CI) 2.12-17.15), larger defects (OR 1.08 per cm2 increase, 95% CI 1.03-1.14), closure with flaps (OR 6.35, 95% CI 1.33-30.28) and secondary intention (OR 3.01, 95% CI 1.11-8.13). These characteristics were also associated with higher risk of clinically suspected SSI regardless of culture results with slightly lower ORs. In conclusion, the risk of acquiring a SSI is increased in surgeries performed on the ear, in larger wounds and in defects closed with flaps or healed by secondary intention.

Preoperative management of antithrombotic medication in Mohs micrographic surgery.

© 2015 The Authors. doi: 10.2340/00015555-2090 Journal Compilation

Subtyping Basal Cell Carcinoma by Clinical Diagnosis Versus Punch Biopsy

International guidelines on the diagnosis and treatment of basal cell carcinoma (BCC) recommend a punch biopsy in the majority of clinically suspected BCC prior to treat ment. This is to confirm diagnosis and to identify the histological subtype (superficial, nodular, aggressive), which is necessary to know for optimal treatment selection (1, 2). A punch biopsy can detect the most aggressive subtype in 84–92% of cases, but has the disadvantages of discomfort for the patient and costs for the health care system (3–5). In contrast, clinical diagnosis is a painless, and possibly money-saving procedure (6). However, the difference in diagnostic accuracy of BCC subtyping between punch biopsy and clinical diagnosis has never been evaluated. This study compares the diagnostic accuracy of clinical assessment and histological diagnosis by punch biopsy for subtyping of BCC. Furthermore, we evaluated the impact of omitting the punch biopsy on treatment recommendations.

使用分级5-氨基酮戊酸20%和二级局部氨基乙酰丙酸甲酯通过局部光动力疗法来治疗表浅性基底细胞癌:随机对照试验结果

光动力疗法(PDT)常用于治疗表浅性基底细胞癌(sBCC)。它通过将卟啉前体膏涂抹于所影响的皮肤部位,并盖上敷料来治疗。几小时后揭开闭合的敷料,使用高强度的可见光照射皮肤部位,使癌细胞死亡。荷兰有两种卟啉前体,分别为5‐氨基酮戊酸20% (ALA)和氨基乙酰丙酸甲酯(MAL)。在传统MAL PDT中,皮肤每隔一周照射一次(光治疗)。对于ALA,皮肤每隔两小时接受两次不同的照射。这被称为分级ALA‐PDT。在这项来自荷兰的研究中,我们调查了这种分级ALA‐PDT是否优于传统MAL‐PDT。162名患者被随机分成两组。82名患者使用分级ALA‐PDT治疗,80名患者使用传统MAL‐PDT。12个月后,ALA‐PDT组有6起治疗失败(sBCC复发),MAL‐PDT组有13起治疗失败。尽管MAL‐PDT组的治疗失败数量高出一倍,但这一差异不具有统计显著性。其次,我们调查了两个治疗组的疼痛分数,因为PDT据悉会引起严重的灼烧感。我们发现与MAL‐PDT相比,ALA‐PDT会导致更剧烈的疼痛和更多副作用,例如红斑(红疹,如晒斑)、伤口/糜烂和囊泡(小水泡)。因此,对于治疗sBCC,相比MAL‐PDT,ALA‐PDT趋向于有更好的疗效,尽管差异并不显著。

A Clinical Prediction Model for Surgical Site Infections in Dermatological Surgery

To adequately identify patients at risk for surgical site infection in dermatological surgery and effectively prescribe antibiotic prophylaxis, a prediction model may be helpful. Such a model was developed using data from 1,407 patients who underwent dermatological surgery without antibiotic prophylaxis. The multivariable logistic regression model included type of closure, tumour location and defect size as risk factors. Bootstrapping was used for internal validation. The overall performance of the model was good, with an area under the curve of 84.1%. The decision curve analysis showed that the model is potentially useful if one is willing to treat more than 8 patients with antibiotic prophylaxis to avoid one infection. For those who prefer more restrictive use of antibiotic prophylaxis, a default strategy of treating no patients at all with prophylaxis would be the best choice. External validation of the model is required before it can be widely applied.