(BQ) Part 2 book Requisites in dermatology - Dermatologic surgery presents the following contents: Basic excisional surgery, suture techniques, sture materials, flaps, skin grafts, nail surgery, mohs micrographic surgery, surgical complications,...
Christine Poblete-Lopez Key Points • The simple excision is the bread and butter of any dermatologist’s surgical practice • Performed for diagnostic or therapeutic purposes, it is a relatively simple procedure that one should master • Knowledge of surgical anatomy is of utmost importance! • There are variations in the ellipse that are particularly useful in certain anatomic regions of the skin, such as the crescent, S-plasty and M-plasty excisions • If proper surgical technique and meticulous hemostasis are maintained, surgical complications can be minimized and a cosmetically elegant scar can result Introduction The simple excision is the foundation of cutaneous surgery Though seemingly complex to a novice, it should be mastered by any dermatologist seeking to perform this relatively simple procedure in an office-based setting Knowledge of surgical anatomy, tumor biology, local anesthetics, instrumentation, and suturing techniques is crucial prior to performing any cutaneous surgery In addition, a thorough preoperative evaluation is essential to help minimize postoperative complications When performed properly and meticulously, a fine cosmetically acceptable scar results Application The simple excision is designed to remove entire lesions for histopathologic examination, as well as surgical cure Whether it is a benign lesion that is troublesome (e.g cyst, lipoma, or dermato fibroma) or cosmetically bothersome (e.g nevus on the chin or cheek), or a lesion of uncertain biologic behavior (e.g clinically atypical nevus on the back), these lesions can be excised in an elliptical fashion to achieve definitive histopathologic 10 Chapter Basic excisional surgery diagnosis, as well as complete removal On the other hand, a surgical excision can be the definitive treatment of choice for selected malignant lesions that have been diagnosed on a prior biopsy However, in this case, margins for cure, as well as cosmetic and functional challenges regarding the final scar, must be taken into consideration, making the excision a bit more challenging For example, a well demarcated basal cell carcinoma on the extremity can usually be excised with a 4–5-mm margin of normal appearing skin around the circumference of the lesion A superficial spreading melanoma on the forearm with a Breslow level of 0.43 mm, for example, can be excised with a 10-mm margin down to the fascia See Table 10-� for general recommendations on margins of excision Techniques Orienting the ellipse Whether one is working on the head and neck region, or the trunk and extremities, a working knowledge of anatomic danger zones (see Chapter 1) and surface anatomy, with regard to relaxed skin tension lines, contour lines, and cosmetic units is essential (Figs 10-� & 10-2) Planning your incision lines along relaxed skin tension lines, natural skin lines, cosmetic units, and boundaries can increase the likelihood of a cosmetically acceptable scar, by providing optimal camouflage and allowing the wound to be closed under the least amount of tension Relaxed skin tension lines are formed by the pull of the underlying muscles at the site of their insertion on the overlying skin In general, the skin creases form in a pattern that is perpendicular to the direction of the underlying muscle contraction Wounds oriented parallel to the skin creases or skin tension lines close under less tension, and result in well camouflaged, thin scars Although Figures 10-1 and 10-2 show these lines 124 Dermatologic Surgery Table 10-1 General rules for margins of excision Preparing for the excision Type of lesion Margin (mm) Benign lesions 0–2 Atypical nevi 3–4 Nonmelanoma skin cancer (not an indication for Mohs surgery) 4–6 Melanoma (Breslow level ≤ 1 mm) 10 Melanoma (Breslow level >1 mm) 20–30 Planning the excision should be done with the patient upright, to minimize apparent distortion of the relaxed skin tension lines Marking of the planned excision should be done prior to infiltrating the anesthetic This minimizes distortion of the skin tension lines and avoids obscuring the lesion margins Prior to marking, the area should be cleansed with 70% isopropyl alcohol Any hair in and around the operative site that will interfere with the surgical procedure should be secured away from the operative field or clipped with scissors Preoperative shaving creates microabrasions in the skin and should be avoided due to increased risk of wound infection Lines of planned excision may now be drawn using a skin marking pen, fine-tipped permanent marker, or a wooden applicator dipped in gentian violet The surgical site is then anesthetized, including a sufficient margin to allow for wide undermining (Fig 10-� 4) The area is then prepped with an appropriate surgical scrub (e.g povidone–iodine, chlorhexidine) (see Chapter 2: Antisepsis) Chlorhexidine should be used with caution around the eye, as it can cause corneal ulceration, and avoided completely around the ear if there is chance of a tympanic membrane perforation Povidone–iodine should be avoided in patients with known allergy to iodine Universal precautions should be employed at this point, including the use of sterile gloves, masks, and eye protection for surgical personnel The surgical field is then draped with sterile towels, or disposable sheets, and the excision carried out under aseptic conditions in general, many variations exist Therefore, one should consider each patient individually In elderly patients, the lines are quite evident In younger individuals, asking them to make an exaggerated facial expression or pinching the skin and identifying the natural skin lines will aid in determining the axis of orientation If there is question as to optimal suture line orientation, the lesion should first be removed in a circular fashion, and undermined This maneuver allows the skin’s inherent elasticity to determine along which axis it will form an oval The surgeon can then extend the incision along this axis to form an ellipse Cosmetic subunit junction lines are formed at the borders of fixed structures on the face, and divide the face into cosmetic units that have similar skin color, texture, sebaceous gland quantity and quality, and hair content (see Fig 10-� 2) Excisions should be designed and contained within a single cosmetic unit and resultant scars planned so that they lie within cosmetic subunit junction lines This best maintains the normal anatomy of the face, in particular, as well as making the scar less conspicuous than one that crosses multiple cosmetic units Some surgeons even enlarge their excisions so that the resultant scar will lie along a subunit junction line, emphasizing the importance of these boundary lines over relaxed skin tension lines As a general rule, the length of the ellipse should be three to four times the width, and the tips drawn at an angle ranging from 30° to 75° (Fig 10-� 3) This ensures that the wound edges will come together without “dog ears” or redundancies at the apices of the ellipse, and that the scar will lay down flat against the skin If possible, the length of the ellipse should be drawn along the length of the lesion, to minimize the length of the scar However, there are times when a longer, well placed scar, such as one that is oriented within a contour line or along skin tension lines, will result in a more cosmetically acceptable scar than a shorter, more conspicuous, one Performing the excision For the majority of basic excisional surgery, a no 15 scalpel blade attached to a Bard Parker handle, is appropriate (see Chapter 4: Surgical instruments) For small, delicate excisions, the scalpel should be held vertically like a pen For larger excisions, it may be preferable to hold it horizontally, like a steak knife Prior to starting the incision, traction should be placed on the wound edges by the surgeon’s nondominant hand or by a surgical assistant Next, the skin is incised at a 90° angle, starting at the distal tip of the ellipse The incision should be carried out toward the surgeon, ideally with enough pressure to incise the skin up to the subcutaneous fat The angle of the scalpel is decreased to about 45° when incising along the curvature of the ellipse, with the belly of the blade in contact with the skin This is the sharpest part of the blade (Fig 10-� 5) Again, the angle of the blade is held at 90° when approaching the other apex of the ellipse (Fig 10-� 6) The incision is repeated a b c Figure 10-1 Relaxed skin tension lines (a) face; (b) trunk; (c) extremities Chapter Basic excisional surgery 10 125 126 Dermatologic Surgery Lateral ridge of nose Infraorbital crease Nasofacial sulcus Nasoalar crease Nasal ala Nasal tip Melolabial crease Philtral crest Vermillion border Labiomental crease a Figure 10-2 Contour lines and cosmetic units cm 30º cm Figure 10-3 Dimensions of the ellipse b Figure 10-5 With the nondominant hand providing tension opposite the side of incision, the tip of the blade is used to incise the apex of the ellipse (a) and the belly of the blade incises the curvature of the ellipse (b) Figure 10-4 Anesthetizing a previously marked planned excision Chapter Basic excisional surgery 10 Figure 10-6 The angle of the blade during incision Variations of the ellipse Crescentic excision Figure 10-7 Avoid “fishtail” or “cross-hatching” Sometimes also referred to as the “pregnant belly,” the crescentic excision takes advantage of sides of unequal length, and results in a curvilinear scar As the arc of the crescent determines the resultant scar, the ellipse could be oriented along curved skin tension lines or cosmetic subunit junction lines The wound should be closed using the rule of halves, thereby minimizing any resulting Burrow’s triangles from the unequal sides Areas of potential use include the cheek (along the malar eminence) and the chin, for example (Fig 10-� 9) S-plasty excision Correct Also called “lazy S,” the S-plasty excision is useful when performing an excision along a convex surface, for example the forearm, shin, or jaw This minimizes the contraction and buckling seen along the length of the scar Similarly, closing the wound with the rule of halves is helpful (Fig 10-10) M-plasty excision Figure 10-8 “Staircasing” at the other side of the ellipse Care should be taken to avoid “cross-hatching” or “fishtails” at the apices of the ellipse (Fig 10-� 7) Try to avoid multiple shallow incisions, in order to minimize 8) “stair-casing” of the wound margins (Fig 10-� The M-plasty excision is effective in reducing the length of scar when it would otherwise encroach on a neighboring functional or cosmetic structure This may be planned prior to the excision, or may be used in repairing a redundant standing cone (or “dog ear”) deformity At the apex of the ellipse used to perform the M-plasty, a tip stitch may be helpful to minimize necrosis of the tip (Fig 10-11) 127 128 Dermatologic Surgery Figure 10-9 Crescentic excision a Figure 10-10 S-plasty excision Specimen removal and undermining Once you have incised through the full thickness of the skin, the lesion is transected at its base, sharply, with the blade, or bluntly with dissecting scissors, at the level of the subcutaneous fat (Fig 10-12 & Table 10-� 2) To aid removal of the specimen, a skin hook or toothed forceps is used to pick up the distal apex of the ellipse, and the base is transected as described Try to remove the specimen with uniform thickness and avoid beveling the wound edges when making your incision, to minimize “scooping” or “boating” of the specimen and wound edges, as this will ultimately affect the proper apposition of the wound edges (Fig 10-13) Undermining serves a number of purposes that result in a more cosmetically pleasing scar: • It reduces the tension on the wound edges • It creates a horizontal scar band that parallels the skin surface • It restores the contour of the skin surrounding the excision b Figure 10-11 M plasty excision (a) Design of the M plasty and end result; (b) M plasty excision illustrating tip stitch a Chapter Basic excisional surgery 10 b Figure 10-12 Sharp or blunt transection of the base of the specimen Figure 10-13 Avoid “boating” or “scooping” the specimen a b Figure 10-14 Blunt undermining of the wound edges using the closed–open technique Note the use of a skin hook to minimize trauma to the skin edge Undermining is performed by blunt dissection of the surrounding wound edge, around the entire border of the excision, including the apices of the ellipse The level for undermining is dictated by the anatomic location of the wound (see Table 10-� 2) This may be done using a blunt-tipped dissecting scissors (see Chapter 4: Surgical instruments), or sharply with caution using the blade Using the scissors, the closed to open technique is used (Fig 10-14) To minimize damage to the wound edge, a skin hook is used to visualize the field and expose the level of undermining The scissors is 129 130 Dermatologic Surgery Table 10-2 Planes of undermining Location Plane of undermining Face Superficial fat Scalp Subgaleal Neck Superficial fat Trunk and extremities Mid to deep subcutaneous fat above muscular fascia Hands and feet Immediately subdermal inserted with its tips closed, and then opened to separate fibrous attachments aside, as well as cutting the intervening fibers The extent of undermining depends on the laxity of the surrounding skin In general, the width of undermining is the distance equal to, or up to double the length of, the short axis of the ellipse For example, excision of a lesion with a diameter of a 1 cm would necessitate undermining 1–2 cm laterally Ultimately, undermining is done to the extent that is necessary to facilitate placement of subcutaneous/intradermal sutures with minimal tension Obtaining hemostasis Complete hemostasis should be achieved to minimize the risk of hematoma formation after surgery One should be very meticulous, taking into consideration the effects of epinephrine during the procedure and its expected vasodilatation postoperatively This can be achieved using electrodessication and electrocoagulation techniques For small bleeding vessels, a direct touch to the vessels using the handheld electrode is sufficient When larger vessels are transected, use of a tissue forceps to elevate and isolate the vessel is helpful The electrode is then touched to the distal aspect of the forceps, which transmits the energy b c Figure 10-15 (a) Direct touch to smaller vessels; (b) isolation of larger vessels with tissue forceps; (c) transmission of energy by touching the electrode tip to the tissue forceps Figure 10-16 “Figure of 8” technique of suture ligation to the isolated vessel (Fig 10-15) This minimizes extensive tissue destruction in the surrounding area, as well as optimizing the ability of the electrode to coagulate in a drier wound bed Be meticulous but not be overzealous in coagulating the bleeding, especially that seen along the epidermal/dermal wound edge (resulting from visible telangiectasias), as this may increase the risk infection and prolonged healing, and adversely affect the resultant appearance of the scar Even larger bleeding vessels, especially visible arteries, are more reliably treated with suture ligation, using the figure-of-eight technique (Fig 10-16) Using an absorbable suture, such as chromic, the vessel is visualized and isolated with a fine-tipped hemostat, and the suture is passed in and across the vessel in a diagonal and out, and again, from the opposite side, in and across the vessel in a diagonal and out, and tied off as the hemostat is removed This effectively clamps the actively bleeding vessel Closing the surgical wound Once meticulous hemostasis is achieved, and wide undermining is performed, the wound is ready for closure The goal of closure is to produce a a Figure 10-17 Layered closure of the excision Chapter Basic excisional surgery 10 well approximated and everted wound edge with minimal tension, thereby resulting in a cosmetically elegant scar The nature of the surrounding skin, and the size and depth of the wound, will determine which suture material and closure technique is appropriate (see Chapter 12: Suture materials) In general, excision of full-thickness lesions necessitates a layered closure, which consists of a buried inverted layer of absorbable intradermal/ subcutaneous sutures and a percutaneous layer of suture, tissue adhesive or adhesive tapes (Fig. 10-17) The intradermal/subcutaneous sutures provide the support following removal of the percutaneous sutures, when the wound has only achieved 5% of its final tensile strength A layered closure (see Chapter 11: Suture techniques) achieves the following: • Allows elimination of any potential dead space, thereby minimizing the risk of hematoma or seroma formation, which can serve as a nidus for infection • Approximates the wound edges with proper eversion • Reduces the tension along the wound edges, thereby resulting in a well healed scar Dog ear repair Burrow’s triangles, standing cone deformity, and “dog ears” – all refer to redundant skin that is formed from wounds with apical angles greater than 30°, or those with unequal lengths at the time of closure In general, this tissue redundancy is located at the apices of the ellipse, but may occur along the length of the longer wound edge The repair is performed by pulling the redundant tissue perpendicular to the direction of closure, incising one half of the tissue until another apex is reached This incised flap is draped over the incision, and the other half of b 131 132 Dermatologic Surgery a b Figure 10-18 Management of dog ear deformity 246 Dermatologic Surgery Photodynamic therapy Electron excited state (S1 ) Triplet state (T1 ) Singlet oxygen ( 1O2 ) Phosphorescence Tumor diagnosis Absorption Fluorescence Oxygen ( O2) Photosensitizer (PpIX) Electron ground state (S0) Light Figure 20-1 Diagram showing energy levels of photosensitizer excitation (adapted from Hasan et al 2006) Table 20-1 FDA-approved systems for PDT Topical agent Brand name Manufacturer Light source Indication Available in USA δ-Aminolevulinic acid HCl, 20% solution Levulan Kerastick DUSA, USA Blu-U, 417 nm (approx.), noncoherent Actinic keratosis (nonhyperkeratotic, fluorescent on head and scalp), 2000 Yes Methyl aminolevulinate, 16% cream Metvix PhotoCure ASA, Norway Aktilite, 634 nm (approx), lightemitting diode, noncoherent Actinic keratosis, 2004 No IX (PpIX) rapidly accumulates in these cells (Fig 20-2) Some dysplastic cells also exhibit decreased ferrochelatase activity and lower the ferric ion concentration, which promotes further accumulation of PpIX Dermatology is an ideal arena for the development of PDT because photosensitizers can be applied topically, avoiding some potential adverse events such as the generalized photosensitivity associated with the systemic delivery of photosensitizers PDT of the skin also adds a second degree of selectivity In addition to preferentially increased ALA uptake and PpIX production by malignant or damaged cells, light delivery can be easily directed to encompass only involved sites Light source In choosing a light source for PDT, three key criteria need to be considered Light must be able to penetrate the tissue containing the photosensitizer Light energy must be able to be delivered mechanistically to the tissue of interest In cutaneous applications, this is usually accomplished easily However, careful considerations must be made regarding the depth of penetration of these light sources Generally, longer wavelengths penetrate more deeply into tissue This may be of importance when considering the condition being treated (see Controversies – Light source) Chapter Photodynamic therapy 20 Cytosol Mitochondrion Heme Fe ferrochelatase Glycine + Succinyl CoA Protoporphyrin IX ALA synthase protoporphyrinogen IX oxidase Protoporphyrinogen δ-Aminolevulinic acid coproporphyrinogen III oxidase Coproporphyrinogen III δ-Aminolevulinic acid Coproporphyrinogen III uroporphyrinogen decarboxylase ALA dehydratase Uroporphyrinogen III Porphobilinogen Hydroxymethylbilane Figure 20-2 Heme synthesis pathway 4.0 3.5 The wavelength must be sufficiently absorbed by the photosensitizer used Blu-U 417 nm Absorption 3.0 Each photosensitizer has a specific absorption spectrum The ideal wavelength used should be well absorbed by PpIX but not by other endogenous chromophores While PpIX readily absorbs light in the Soret band (414 nm), so too other compounds Laser sources used in PDT protocols typically are chosen to lie within secondary absorption peaks of PpIX, such as those at approximately 630 and 570–580 nm Light must be delivered in sufficient energy to activate the photosensitizer Figure 20-3 PpIX spectrum from 300 to 800 nm Blu-U, noncoherent (blue) light source Oxygen Oxygen is critical to the generation of singlet oxygen species This may be of clinical relevance in hypoxic tissues 1.5 1.0 0.5 300 400 500 600 700 800 Wavelength (nm) Absorption The light source chosen must have a sufficiently high energy output to make the delivery of sufficient light doses clinically feasible Numerous such sources have been reported, and not necessarily have to be fancy or expensive In fact, early topical PDT experiments were conducted using a slide projector bulb The absorption spectrum of PpIX with an overlay of a few of the more commonly used light sources can be seen in Figures 20-3 & 20-� 2.5 2.0 0.60 0.55 0.50 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0.10 450 IPL 515–1200 nm KTP 532 nm PDL 585 nm PDL 595 nm 500 550 600 650 700 750 Wavelength (nm) Figure 20-4 PpIX spectrum above 450 nm IPL, intense pulsed light; KTP, potassium titanyl phosphate (green) light source; PDL, pulsed dye laser 247 248 Dermatologic Surgery Medical treatment options A variety of dermatologic conditions amenable to medical therapies have been treated with topical PDT (Box 20-1) To date in the USA, only treatment of nonhypertrophic actinic keratoses of the head and scalp is Food and Drug Administration B ox - Medical treatment options other than PDT Actinic keratoses Topical 5-fluorouracil Topical imiquimod Topical diclofenac B ox - Topical retinoids (tretinoin, adapalene, tazarotene) Dermatologic uses for photodynamic therapy Squamous cell carcinoma in situ (Bowen’s disease, erythroplasia of Queyrat) FDA approved Topical 5-fluorouracil Actinic keratoses (approval is for nonhypertrophic actinic keratosis of head and scalp) Topical imiquimod Commonly used in North America or Europe Squamous cell carcinoma (SCC) in situ Basal cell carcinoma (superficial or nodular subtypes) Oral acitretin (chemoprevention) Superficial basal cell carcinoma Topical imiquimod Photorejuvenation Acne vulgaris Small case series, anecdotal reports, or investigational Acne inversa (hidradenitis suppurativa) Verrucae vulgaris Chemoprevention of nonmelanoma skin cancer Cutaneous T-cell lymphoma Cutaneous B-cell lymphoma Keratoacanthoma Rosacea/rhinophyma Molluscum contagiosum Actinic cheilitis Morphea/lichen sclerosus Scleroderma Psoriasis Lichen planus Gorlin’s syndrome (basal cell nevus syndrome) Perioral dermatitis Sebaceous hyperplasia Melasma Alopecia areata (FDA) approved Current international consensus guidelines support the use of topical PDT for the treatment of actinic keratoses, SCC in situ (Bowen’s disease), and superficial BCC Specifically MAL-PDT is recommended for the treatment of nodular BCC Medical treatment alternatives to the afore-mentioned are listed in Box 20-2 Surgical approach There is a great deal of variation in published ALA-PDT treatment protocols Variations in tissue pretreatment (e.g mild chemical peels or curettage), ALA formulation, ALA application time, light source, light dose, or treatment frequency may have significant effects on outcome However, general consensus guidelines have been published for topical ALA-PDT and are listed below Topical ALA-PDT treatment algorithm (Fig 20-5) Pretreatment Dermatophytoses • Continue current topical and systemic medications • Consider pretreatment of hypertrophic actinic keratoses or severe photodamage with a short course of 5-fluorouracil or imiquimod Cutaneous leishmaniasis Light sources Extramammary Paget’s disease • Commonly used light sources are listed in Table 20-2 • Blue light: 15 min when used as single light source, 5–8 min when used in addition to intense pulsed light (IPL) or laser for increased photobleaching Darier’s disease Hailey–Hailey disease Infected leg ulcers Nevus sebaceous Disseminated superficial actinic porokeratosis Port wine stain • Avoid purpuric settings with pulsed dye laser (PDL) • Double pulsing of PDL may be used in the treatment of sebaceous skin, rhinophyma, or rosacea Post-treatment • Titanium dioxide or zinc oxide sunblock • Patient to avoid direct sun exposure for 48–72 h • Apply moisturizers as needed • Patient education should include expectation of desquamation and mild to moderate erythema for 48–72 h Chapter Photodynamic therapy 20 Wash with soap and water or alcohol swab Microdermabrasion (single pass) or acetone scrub (enhances uniform penetration of ALA) Prepare 20% ALA Crush ampules and shake Kerastick for Apply ALA evenly with firm pressure Timing of treatments 30–60-min incubation time Photoprotection • Two to five treatments, 2–4 weeks apart • Vary incubation time and light dose on follow-up treatments to optimize therapeutic effect Remove ALA with soap and water Wipe with alcohol Pearls • Superficial crust and/or scale may be removed via curettage prior to application of ALA to permit increased and more uniform tissue absorption • Though adequate for the treatment of actinic keratoses, acne, and photodamage, short ALA incubation/contact times (30–60 min) may not be adequate for the treatment of other conditions • The most common adverse event is patient iscomfort during light exposure and for a few d hours post-treatment Most patients describe stinging, burning, and/or pruritus • Pain seems to increase with the amount of surface area treated • Ice and cooling devices may help with pain during and immediately after treatment Topical anesthetics seem to provide little, if any, benefit (see Controversies) Furthermore, ALA is unstable at basic pH The use of topical anesthetics such as EMLA (pH 9) should be avoided • Avoid sun exposure post-treatment for 24–48 h atients should wear sunscreen/sunblock, P preferably titanium dioxide or zinc oxide • Newer PDT protocols, aimed at increased PDT efficacy, tolerability, or convenience, include intralesional injection of ALA, fractionated light dosing, induction of keratinocyte differentiation, and “ambulatory PDT” in which patients wear a battery-operated light source at home Comparative outcomes Variation in treatment parameters makes a direct comparison of most PDT trials difficult at best Despite this, consistent success demonstrated with ALA-PDT in the treatment of actinic keratosis and Figure 20-5 Treatment algorithm for topical ALA-PDT nonmelanoma skin cancer (in-situ SCC, superficial BCC, nodular BCC) has prompted recent international consensus support for the use of PDT for the treatment of these entities Representative studies using topical ALA are listed in Table 20-3, with a comparison of respective clearance rates Studies vary significantly in the degree of pretreatment to respective lesions prior to the application of photosensitizer (i.e curettage) Additionally, different follow-up periods make a true assessment of tumor clearance rates difficult The reader is referred to the original reports to make their own judgments regarding these issues Finally, we have omitted a large number of the trials for nonmelanoma skin cancer conducted in Europe using topical MAL-PDT, which is not currently available in the USA There may be potential benefits for MAL-PDT compared with ALA-PDT when treating tumors as described in the next section Controversies Vehicle As mentioned above, numerous formulations of topical photosensitizers have been reported in the literature The only currently FDA-approved formulation of topical PDT available in the USA is Levulan Kerastick (DUSA Pharmaceuticals) Methylation of ALA (MAL) appears to increase absorption of the molecule, presumably leading to increased PpIX production For this reason, some advocate MAL-PDT over ALA-PDT for the treatment of nonmelanoma skin cancer It is unclear, however, whether this leads to substantial 249 250 Dermatologic Surgery Table 20-2 Light sources used for PDT Condition Preferred Alternate Other Actinic keratosis Blue light PDL, IPL Green, yellow, red IPL Blue, PDL Green, yellow Superficial BCC Photodamage Blue for type VI skin Acne PDL + blue (5 min) Blue (8 min) Green, red, yellow, IPL Sebaceous skin PDL, blue IPL Green, yellow, red Rosacea Rhinophyma Blue, noncoherent light source with main peak at 417 nm (Blu-U); IPL, intense pulsed light; PDL, pulsed dye laser (585, 595 nm) Table 20-3 Reported topical PDT regimens using 20% δ-ALAa Indication No of patients/ lesions Application time Light source and dose AK 36/70 14–18 h 243/1909 Results Reference Blue light (417 nm), 2–10 J/cm2, 3–10 mW/cm2 66% CR (88% with 2nd treatment) Jeffes et al (2001) 14–18 h Blue light (417 nm), 10 mW/cm2 83% CR Piacquadio et al (2004) 41/3622 14–18 h open, or 3–4 h occluded FL-PDL (595 nm) laser, 7.5 J/cm2 65–100% CR AlexiadesArmenakas & Geronemus (2003) 24/>4 lesions per patient 1h Blue light (417 nm), 1000 s 50% CR Smith et al (2003) FL-PDL (595 nm), 7.5 J/cm2 SCC in situ (Bowen’s) 32/multiple 15–20 h Blue light (417 nm), 1000 s 94% CR Goldman & Atkin (2003) 18/>4 lesions per patient 1–3 h (± 40% urea for days) Blue light (417 nm), 10 J/cm2 94% CR at 2 h, 87% CR at 1 h Touma et al (2004) 50 lesions 6–8 h 630-nm argonpumped dye laser (repeated qod) 84% CR Calzavara-Pinton (1995) 17 1h IPL, 560-nm filter, 28–32 J/cm2 68% CR Avram & Goldman (2004) 19/20 4h Xenon arc lamp (300 W), 125 J/cm2, 70 mW/cm2 75% after treatment, 100% after treatments Morton et al (1996) 16/61 4h Xenon arc lamp (300 W) 20/33 4h Morton et al (2000) 540 ± 15-nm filter (green) 72% CR, 48% 12 months 630 ±15-nm filter (red) 94% CR, 88% 12 months Xenon arc lamp (300 W), 630 ±15-nm filter, 100 J/cm2, 50–90 mW/cm2 88% CR, weeks Salim et al (2003) Continued Chapter Photodynamic therapy 20 Table 20-3 Reported topical PDT regimens using 20% δ-ALAa—cont’d Indication No of patients/ lesions BCC, superficial 80 lesions 21/80 Application time Light source and dose Results Reference 90% CR, 2–3 months Kennedy et al (1990) 4–6 h Nd:YAG pumped dye laser (630 nm), 60 J/cm2,