Limitations of ALA-PDT as a reliable therapy for AK in clinical practice

Liquid nitrogen cryotherapy effectively and safely improves response of thick actinic keratoses lesions by 5-aminolevulinic acid-based photodynamic therapy: A randomized, prospective, single-blind trial

BACKGROUND

Actinic keratoses (AK) may progress into squamous cell carcinoma. Many combination therapies were used to improve the clearance rate. However, there are limited studies on the efficacy and safety of lesion-directed Liquid nitrogen cryotherapy combined with field-directed photodynamic therapy (PDT).

OBJECTIVE

This study is aimed to determine the efficacy and safety of Liquid nitrogen cryotherapy combined with PDT in Chinese patients with actinic keratosis.

METHODS

A total of 61 patients with AK were selected at the Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College between August 2018 and August 2023. They were randomly divided into PDT plus Liquid nitrogen cryotherapy group (LN-PDT) and control PDT group (C-PDT) with 30 patients and 31 patients, respectively. 27 patients in the LN-PDT group and 28 patients in the C-PDT group completed the clinical sessions. Efficacy, adverse effects, and cosmetic outcomes were recorded and compared between the two groups.

RESULTS

3 months after the final treatment, the clearance rates for total AK lesions were 97.4 % (449/461) in the LN-PDT group and 93.4 % (456/488) in the C-PDT group (P < 0.05). For grade I AK lesions, the clearance rates were 99.2 % (234/237) for the LN-PDT group and 98.3 % (237/241) for the C-PDT group (P >0.05). For grade II lesions, the clearance rates were 97.5 % (156/160) for the LN-PDT group and 91.9 % (172/186) for the CPDT group (P < 0.05). For grade III lesions, the clearance rates of the LN-PDT and C-PDT groups were 87.5 % (58/64) and 78.7 % (47/61), respectively (P < 0.05). The two groups had no significant differences in pain, erythema, edema, hyperpigmentation and scarring. Cosmetic outcomes mainly were excellent or good in both groups with no significant difference.

CONCLUSION

Liquid nitrogen cryotherapy combined with PDT showed higher efficacy on grade II and grade III AK lesions than PDT alone. The two groups have similar adverse effects and cosmetic outcomes.

Photodynamic Therapy in the Treatment of Cancer-The Selection of Synthetic Photosensitizers

Photodynamic therapy (PDT) is a promising cancer treatment method that uses photosensitizing (PS) compounds to selectively destroy tumor cells using laser light. This review discusses the main advantages of PDT, such as its low invasiveness, minimal systemic toxicity and low risk of complications. Special attention is paid to photosensitizers obtained by chemical synthesis. Three generations of photosensitizers are presented, starting with the first, based on porphyrins, through the second generation, including modified porphyrins, chlorins, 5-aminolevulinic acid (ALA) and its derivative hexyl aminolevulinate (HAL), to the third generation, which is based on the use of nanotechnology to increase the selectivity of therapy. In addition, current research trends are highlighted, including the search for new photosensitizers that can overcome the limitations of existing therapies, such as heavy-atom-free nonporphyrinoid photosensitizers, antibody-drug conjugates (ADCs) or photosensitizers with a near-infrared (NIR) absorption peak. Finally, the prospects for the development of PDTs are presented, taking into account advances in nanotechnology and biomedical engineering. The references include both older and newer works. In many cases, when writing about a given group of first- or second-generation photosensitizers, older publications are used because the properties of the compounds described therein have not changed over the years. Moreover, older articles provide information that serves as an introduction to a given group of drugs.

Photodynamic Therapy for Eye, Ear, Laryngeal Area, and Nasal and Oral Cavity Diseases: A Review

Photodynamic therapy (PDT) has emerged as a promising modality for the treatment of various diseases. This non-invasive approach utilizes photosensitizing agents and light to selectively target and destroy abnormal cells, providing a valuable alternative to traditional treatments. Research studies have explored the application of PDT in different areas of the head. Research is focusing on a growing number of new developments and treatments for cancer. One of these methods is PDT. Photodynamic therapy is now a revolutionary, progressive method of cancer therapy. A very important feature of PDT is that cells cannot become immune to singlet oxygen. With this therapy, patients can avoid lengthy and costly surgeries. PDT therapy is referred to as a safe and highly selective therapy. These studies collectively highlight the potential of PDT as a valuable therapeutic option in treating the head area. As research in this field progresses, PDT may become increasingly integrated into the clinical management of these conditions, offering a balance between effectiveness and minimal invasiveness.

Combined Carbon Dioxide Laser with Photodynamic Therapy for Nodular Basal Cell Carcinoma Monitored by Reflectance Confocal Microscopy

Introduction: Basal cell carcinoma (BCC) represents around 80% of all malignant skin cancers worldwide, constituting a substantial burden on healthcare systems. Due to excellent clearance rates (around 95%), surgery is the current gold-standard treatment. However, surgery is not always possible or preferred by patients. Numerous non-surgical therapies, sometimes combined, have been associated with promising tumor free survival rates (80-90%) in non-melanoma skin cancers (NMSCs). Most research has enrolled superficial basal cell carcinomas (sBCCs), with limited recent studies also involving low-risk nodular BCCs (nBCCs). Given lower efficacy rates compared to surgery, close monitoring during the follow-up period is essential for patients treated with non-surgical therapies. Monitoring with dermoscopy is constrained by low sensitivity rates. Reflectance confocal microscopy (RCM) is more sensitive in monitoring non-surgically treated NMSCs. Case presentation: A 41-year-old woman with a single nBCC relapse following photodynamic therapy (PDT) located on the dorsum of the nose presented to our center. Given the aesthetically sensitive location of the lesion and the patient's preference for a non-surgical approach, a combined treatment of CO2 laser and PDT was prescribed. A superpulsed CO2 laser (power: 0.5-3 W, frequency: 10 Hz, spot size 2 mm) with two PDT sessions (2 weeks apart) were conducted. At 6 weeks follow-up, monitoring performed with RCM revealed a reduction but not eradication of basaloid tumor islands. Another 2 sessions of PDT were recommended. At 3, 12 and 30 months of follow-up, the nasal dorsum area of the previous nBBC lesion was noted to be slightly hypopigmented (observed clinically), with a mild erythematous background (observed by dermoscopy). RCM evaluation confirmed the absence of RCM BCC criteria. The cosmetic outcome was very much improved. Conclusions: Combined CO2 laser and PDT for the treatment of a localized nBCC on the dorsum of the nose of a 41-year-old proved to offer tumor free survival at 30-month follow-up, as monitored with RCM. RCM is useful for the evaluation of non-surgical therapies as it has comparably higher sensitivity than dermoscopy and is especially useful in cases of suspected late recurrence. Further studies are needed to validate ongoing tumor free survival following this combined nonsurgical approach in the treatment of nBCC.