Long-term outcomes of aminolevulinic acid photodynamic therapy for treatment of recalcitrant laryngeal premalignant lesions

Mucosal Injection of the Silicon Phthalocyanine Pc 4 in a Rabbit Model-A Pilot Study

OBJECTIVE

The silicon phthalocyanine Pc 4 is a photosensitizing agent previously shown to be a promising treatment for cutaneous neoplasms using photodynamic therapy (PDT). Based on prior preclinical studies, we believe Pc 4-PDT has potential as a targeted treatment of human recurrent respiratory papillomatosis or laryngeal leukoplakia by direct injection into mucosal surfaces.

METHODS

This was a proof-of-concept pilot study assessing direct mucosal injection of Pc 4 into buccal and vocal fold mucosae in a rabbit model. Five New Zealand white rabbits underwent tattooing of bilateral buccal mucosae to delineate injection sites, followed by submucosal injections of control and Pc 4 solutions. Rabbits were monitored for post-injection tolerance. Punch biopsies were obtained from injected mucosa and assessed histopathologically. Once the buccal mucosa was found to be tolerant, vocal folds of three rabbits were injected. The rabbits were then sacrificed, and laryngeal tissue was assessed histopathologically.

RESULTS

All rabbits tolerated injection of Pc 4 and control solutions into buccal mucosa with no evidence of gross visual inflammatory changes and no changes in behavior or masticatory function. Histopathologic analysis of Pc 4 injected buccal and control mucosal tissue revealed mild focal histological changes and no stigmata of diffuse inflammatory reactions. The histopathologic analysis of Pc 4 injected into laryngeal tissue revealed similar findings with addition of mild eosinophilia in one sample.

CONCLUSION

Direct mucosal injection of Pc 4 in rabbit buccal and vocal fold mucosae appears to be well tolerated with no gross inflammatory changes, and only mild histopathologic inflammatory changes observed.

LEVEL OF EVIDENCE

NA Laryngoscope, 135:270-276, 2025.

Malignant Transformation in Glottic Dysplasia Treated With Photoangiolytic LASER - A Systematic Review and Meta-analysis

OBJECTIVE

This systematic review and meta-analysis seeks to characterize the rate of malignant progression among patients with laryngeal dysplasia treated with photoangiolytic laser and compare to prior systematic reviews of conventional surgical approaches.

METHODS

OVIDMedline, Pubmed, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Google Scholar were searched, including terms related to patients with vocal fold dysplasia who were treated by angiolytic laser ablation. Some articles already known to authors or identified through hand searching were included.

RESULTS

Six articles with 155 cases were included. Two studies used potassium titanyl phosphate exclusively, one solely used the pulsed dye laser, and three studies utilized both laser types during the study period. The pooled overall mean of malignant progression for patients with laryngeal dysplasia treated with photoangiolytic laser was 12%, as calculated by conducting a meta-analysis of single arm proportion.

CONCLUSION

Laryngeal dysplasia is a premalignant lesion which confers a risk of progression to malignancy. After biopsy to establish the diagnosis there are multiple surgical techniques available for treatment with the goal of lesion eradication and voice preservation. In our review, there is a low malignant transformation rate for patients treated via with photoangiolytic laser.

A study on the correlation of Doppler ultrasound in the diagnosis of cervical lymph nodes in patients with laryngeal and hypopharyngeal cancers: An observational study

The objective was to assess the diagnostic efficacy of Doppler ultrasound in detecting cervical lymph nodes in patients diagnosed with laryngeal and hypopharyngeal cancers. Patients undergoing surgery for laryngeal and hypopharyngeal cancers in the Otolaryngology Department from January 2021 to January 2023 were included. Two groups, with equal numbers, underwent ultrasound examination and intensive CT examination in the experimental and control groups, respectively, along with routine cervical lymph node dissection. A resident with over 6 years of clinical experience in the otolaryngology department performed routine bilateral cervical lymph node palpation. Sensitivity, specificity, and validity were compared among different examination methods. The McNemar test assessed specificity and sensitivity between palpation, color Doppler ultrasonography, and enhanced CT, while the Kappa concordance test evaluated the concordance between the 2 examination methods. Data were statistically analyzed using SPSS 23.0. Palpation showed a diagnostic sensitivity (DS) of 52.83% and specificity of 91.11% for all patients with cervical lymph node metastasis. Ultrasonography demonstrated a DS of 77.78% and specificity of 81.82% in patients with cervical lymph node metastasis, while intensive CT had a DS of 75.86% and specificity of 60.00%. Statistical significance (P < .05) was observed in the sensitivity between palpation and ultrasonography, and between palpation and enhanced CT. The specificity between enhanced CT and ultrasonography (P = .021) and between palpation and enhanced CT scan (P = .003) both showed statistical significance (P < .05). Doppler ultrasound yields diagnostic results highly consistent with pathological diagnoses in patients with laryngeal and hypopharyngeal cancers. Utilizing Doppler ultrasound can enhance the accuracy of diagnosing these cancers, aiding physicians in devising more suitable treatment plans for patients.

5-Aminolevulinic Acid Fluorescence-Guided Surgery in Head and Neck Squamous Cell Carcinoma

OBJECTIVES

To determine the utility of 5-aminolevulinic acid (5-ALA) fluorescence for resection of head and neck carcinoma.

METHODS

In this prospective pilot trial, 5-ALA was administered as an oral suspension 3-5 h prior to induction of anesthesia for resection of head and neck squamous cell carcinoma (HNSCC). Following resection, 405 nm blue light was applied, and fluorescence of the tumor as well as the surgical bed was recorded. Specimen fluorescence intensity was graded categorically as none (score = 0), mild (1), moderate (2), or robust (3) by the operating surgeon intraoperatively and corroborated with final pathologic diagnosis.

RESULTS

Seven patients underwent resection with 5-ALA. Five (83%) were male with an age range of 33-82 years (mean = 60). Sites included nasal cavity (n = 3), oral cavity (n = 3), and the larynx (n = 1). All specimens demonstrated robust fluorescence when 5-ALA was administered 3-5 h preoperatively. 5-ALA fluorescence predicted the presence of perineural invasion, a positive margin, and metastatic lymphadenopathy. Two patients had acute photosensitivity reactions, and one patient had a temporary elevation of hepatic enzymes.

CONCLUSIONS

5-ALA induces robust intraoperative fluorescence of HNSCC, capable of demonstrating a positive margin, perineural invasion, and metastatic nodal disease. Although no conclusions are there about the safety of this drug in the head and neck cancer population, our study parallels the extensive safety data in the neurosurgical literature. Future applications may include intraoperative assessment of margin status, diagnostic accuracy, and impacts on survival.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:741-748, 2024.

Office-Based Photodynamic Therapy Using Locally Applied 5-aminolevulinic Acid and 635 nm Laser for Laryngeal Leukoplakia

OBJECTIVE

Photodynamic therapy (PDT) is a minimally invasive method with strong tissue selectivity and nonthermal effects. We aim to investigate the efficacy of an in-office method utilizing PDT with local application of 5-aminolevulinic acid (ALA) and 635 nm diode laser for treating laryngeal leukoplakia.

STUDY DESIGN

Retrospective cohort study.

SETTING

Outpatient clinic-tertiary medical center.

METHODS

This study reviewed 32 patients with laryngeal leukoplakia, including 11 recurrent cases after surgery. All the procedures were performed in an office setting under topical anesthesia. Fifteen percent ALA solution was locally applied to the lesion through a flexible laryngoscope. Light illumination was performed using a 635 nm diode laser through a 400 μm optic fiber. The power density was 165 mW/cm² to reach 100 J/cm² . Results of laryngostroboscopy and voice evaluation during follow-up were collected.

RESULTS

The mean follow-up was 7.91 ± 4.83 (3-18) months. Thirty-nine procedures were performed, including 1 session for 27 patients, 2 sessions for 3 patients, and 3 sessions for 2 patients. The total response rate was 96.875% (31/32), including complete responses in 26 (81.25%) patients, partial responses in 5 patients (15.625%), and no response in 1 patient (3.125%). It appeared that PDT selectively eliminated the leukoplakia without affecting lamina propria and the surrounding normal mucosa remained unharmed. Scores of Voice Handicap Index-10, jitter, shimmer, and harmonic-to-noise ratio were significantly improved after PDT.

CONCLUSION

Office-based PDT is an effective, repeatable, and practical method for treating laryngeal leukoplakia. Local application of ALA is sufficient to achieve photodynamic reactions. PDT could eliminate laryngeal leukoplakia selectively while protecting the normal laryngeal structure.

Long-term effect of photodynamic therapy on oral squamous cell carcinoma and epithelial dysplasia

BACKGROUND

Oral squamous cell carcinoma (OSCC) treatment consists mainly of surgery, chemotherapy, and radiotherapy, alone or in combination. Epithelial dysplasia (ED) is also treated with surgery. However, these treatments can induce functional and/or aesthetic disturbances. Photodynamic therapy (PDT) can preserve organs. Although short-term studies have shown good progress, long-term evaluations have not yet been conducted. This study aimed to clarify the long-term effects of PDT on OSCC and ED.

METHODS

Patients who underwent PDT with the first (porfimer sodium) or second generation photosensitizers (talaporfin sodium) for early OSCC (T1 and T2) and ED were included in this study. The long-term prognosis was assessed.

RESULTS

Twenty-three patients were included. Complete response (CR) was observed in 19 patients (82.6%) and partial response (PR) in 4 patients (17.4%) 4 weeks after PDT. Regarding long-term progress, local region recurrence occurred in 11 of 19 CR cases (57.9%), and the term of recurrence was 27.4 ± 30.4 months. Surgical resection was performed in all local recurrence and PR cases, and 3 patients died of the underlying disease.

CONCLUSIONS

PDT provides a good outcome in the short term, but its long-term effects are limited.

Long-term voice outcomes of laryngeal framework surgery for unilateral vocal fold paralysis

OBJECTIVE

To evaluate the short- and long-term voice outcomes after unilateral medialization thyroplasty (MT) and unilateral medialization thyroplasty with arytenoid adduction (MT + AA) in patients with unilateral vocal fold paralysis.

METHODS

Voice outcomes were assessed preoperatively, and postoperatively at 3 and 12 months according to a standardized protocol. Voice assessment was performed using Voice Handicap Index (VHI), GRBAS Grade, Maximum Phonation Time (MPT), s/z-ratio and subjective numeric rating scales on voice quality, effort, performance and influence on life.

RESULTS

Sixty-one patients were included (34 MT and 27 MT + AA). Significant pre- to postoperative improvements were seen in all voice outcome parameters. No significant differences in post-operative values were identified between the groups.

CONCLUSION

Based on our findings, we conclude that patients with unilateral vocal fold paralysis who undergo MT and MT + AA achieve comparable and significant long time voice improvement, although voices do not completely normalize. We also conclude that this does not mean that AA is a superfluous procedure, but can indicate the accurate identification of patients in need of the additional AA procedure based on clinical parameters.