Zaid Hamdoon

In vitro examination of suspicious oral lesions using optical coherence tomography

We compared findings of optical coherence tomography (OCT) with histopathological results of suspicious oral lesions to assess the feasibility of using OCT to identify malignant tissue. Thirty-four oral lesions from 27 patients had swept-source frequency-domain OCT. Four variables were assessed (changes in keratin, epithelial, and sub-epithelial layers, and identification of the basement membrane) and from this we calculated whether or not there were architectural changes. These data were then compared with histopathological results. Two clinicians, who were unaware of the clinical and histopathological diagnoses, decided whether biopsy was necessary. The basement membrane was recognised in only 15 oral lesions. OCT could identify diseased areas but could not provide a diagnosis or differentiate between lesions. The two clinicians, who recommended biopsy agreed in all cases. This pilot study confirms the feasibility of using OCT to identify architectural changes in malignant tissues.

Photodynamic therapy outcome for oral dysplasia

Photodynamic therapy (PDT) is a minimally invasive surgical intervention used in the management of tissue disorders. It can be applied before, or after, any of the conventional modalities, without compromising these treatments or being compromised itself.

Photodynamic therapy outcome for T1/T2 N0 oral squamous cell carcinoma

This new prospective clinical study assessed the oncological outcomes following surface illumination mTHPC‐photodynamic therapy of T1/T2 N0 oral squamous cell carcinoma (OSCC) patients.

Photodynamic therapy in the management of potentially malignant and malignant oral disorders

Photodynamic therapy (PDT) is a minimally-invasive surgical tool successfully targeting premalignant and malignant disorders in the head and neck, gastrointestinal tract, lungs and skin with greatly reduced morbidity and disfigurement. The technique is simple, can commonly be carried out in outpatient clinics, and is highly acceptable to patients. The role of photodynamic therapy in the management of oral potentially malignant disorders and early oral cancer is being discussed.

Optical coherence tomography-guided photodynamic therapy for skin cancer: Case study

Photodynamic therapy (PDT) has been identified as a successful therapy for skin cancer. This case study investigates the role of optical coherence tomography (OCT) in lesion (squamous cell carcinoma) mapping, assisting the surgeon to correctly deliver PDT and monitor the outcome. Optical coherence tomographic images were acquired pre-treatment to assess tumour extent and margins to enable guidance of the PDT. Tomographic images taken post-PDT up to 6 months revealed complete response to the treatment and no recurrence. OCT-guided PDT is one of the promising approaches to efficiently discriminate between tumor involved and noninvolved margins. It reduces the untoward healthy tissue necrosis and provides an encouraging monitoring of the healing process.

Disulfonated tetraphenyl chlorin (TPCS2a)-induced photochemical internalisation of bleomycin in patients with solid malignancies: a phase 1, dose-escalation, first-in-man trial

BACKGROUND Photochemical internalisation, a novel minimally invasive treatment, has shown promising preclinical results in enhancing and site-directing the effect of anticancer drugs by illumination, which initiates localised chemotherapy release. We assessed the safety and tolerability of a newly developed photosensitiser, disulfonated tetraphenyl chlorin (TPCS2a), in mediating photochemical internalisation of bleomycin in patients with advanced and recurrent solid malignancies. METHODS In this phase 1, dose-escalation, first-in-man trial, we recruited patients (aged ≥18 to <85 years) with local recurrent, advanced, or metastatic cutaneous or subcutaneous malignancies who were clinically assessed as eligible for bleomycin chemotherapy from a single centre in the UK. Patients were given TPCS2a on day 0 by slow intravenous injection, followed by a fixed dose of 15 000 IU/m(2) bleomycin by intravenous infusion on day 4. After 3 h, the surface of the target tumour was illuminated with 652 nm laser light (fixed at 60 J/cm(2)). The TPCS2a starting dose was 0·25 mg/kg and was then escalated in successive dose cohorts of three patients (0·5, 1·0, and 1·5 mg/kg). The primary endpoints were safety and tolerability of TPCS2a; other co-primary endpoints were dose-limiting toxicity and maximum tolerated dose. The primary analysis was per protocol. This study is registered with ClinicalTrials.gov, number NCT00993512, and has been completed. FINDINGS Between Oct 3, 2009, and Jan 14, 2014, we recruited 22 patients into the trial. 12 patients completed the 3-month follow-up period. Adverse events related to photochemical internalisation were either local, resulting from the local inflammatory process, or systemic, mostly as a result of the skin-photosensitising effect of TPCS2a. The most common grade 3 or worse adverse events were unexpected higher transient pain response (grade 3) localised to the treatment site recorded in nine patients, and respiratory failure (grade 4) noted in two patients. One dose-limiting toxicity was reported in the 1·0 mg/kg cohort (skin photosensitivity [grade 2]). Dose-limiting toxicities were reported in two of three patients at a TPCS2a dose of 1·5 mg/kg (skin photosensitivity [grade 3] and wound infection [grade 3]); thus, the maximum tolerated dose of TPCS2a was 1·0 mg/kg. Administration of TPCS2a was found to be safe and tolerable by all patients. No deaths related to photochemical internalisation treatment occurred. INTERPRETATION TPCS2a-mediated photochemical internalisation of bleomycin is safe and tolerable. We identified TPCS2a 0·25 mg/kg as the recommended treatment dose for future trials. FUNDING PCI Biotech.

Structural validation of oral mucosal tissue using optical coherence tomography

BackgroundOptical coherence tomography (OCT) is a non-invasive optical technology using near-infrared light to produce cross-sectional tissue images with lateral resolution.ObjectivesThe overall aims of this study was to generate a bank of normative and pathological OCT data of the oral tissues to allow identification of cellular structures of normal and pathological processes with the aim to create a diagnostic algorithm which can be used in the early detection of oral disorders.Material and methodsSeventy-three patients with 78 suspicious oral lesions were referred for further management to the UCLH Head and Neck Centre, London. The entire cohort had their lesions surgically biopsied (incisional or excisional). The immediate ex vivo phase involved scanning the specimens using optical coherence tomography. The specimens were then processed by a histopathologist.Five tissue structures were evaluated as part of this study, including: keratin cell layer, epithelial layer, basement membrane, lamina propria and other microanatomical structures. Two independent assessors (clinician and pathologist trained to use OCT) assessed the OCT images and were asked to comment on the cellular structures and changes involving the five tissue structures in non-blind fashion.ResultsCorrect identification of the keratin cell layer and its structural changes was achieved in 87% of the cohort; for the epithelial layer it reached 93.5%, and 94% for the basement membrane. Microanatomical structures identification was 64% for blood vessels, 58% for salivary gland ducts and 89% for rete pegs. The agreement was “good” between the clinician and the pathologist.OCT was able to differential normal from pathological tissue and pathological tissue of different entities in this immediate ex vivo study. Unfortunately, OCT provided inadequate cellular and subcellular information to enable the grading of oral premalignant disorders.ConclusionThis study enabled the creation of OCT bank of normal and pathological oral tissues. The pathological changes identified using OCT enabled differentiation between normal and pathological tissues, and identification of different tissue pathologies.Further studies are required to assess the accuracy of OCT in identification of various pathological processes involving the oral tissues.

CO2 lasers in the management of potentially malignant and malignant oral disorders

The CO2 laser was invented in 1963 by Kumar Patel. Since the early 1970s, CO2 laser has proved to be an effective method of treatment for patients with several types of oral lesions, including early squamous cell carcinoma.Laser surgery of oral premalignant disorders is an effective tool in a complete management strategy which includes careful clinical follow-up, patient education to eliminate risk factors, reporting and biopsying of suspicious lesions and any other significant lesions. However, in a number of patients, recurrence and progression to malignancy remains a risk. CO2 laser resection has become the preferred treatment for small oral and oropharyngeal carcinomas. Laser resection does not require reconstructive surgery. There is minimal scarring and thus, optimum functional results can be expected.New and improved applications of laser surgery in the treatment of oral and maxillofacial/head and neck disorders are being explored. As more surgeons become experienced in the use of lasers and as our knowledge of the capabilities and advantages of this tool expands, lasers may play a significant role in the management of different pathologies.

Adenoid cystic carcinoma of the tongue base treated with ultrasound-guided interstitial photodynamic therapy: A case study

Adenoid cystic carcinoma is a malignant neoplasm arising from the salivary glands. It accounts for 10-15% of all salivary gland neoplasms, representing 1-2% of malignant neoplasms of the head and neck. It is characterized by slow growth, diffuse invasion and potential to produce distant metastases, mainly to the lungs and bone. We present a case of adenoid cystic carcinoma of the base of tongue treated with ultrasound guided transcutaneous interstitial photodynamic therapy (PDT) as a salvage treatment.

Photodynamic therapy in the management of basal cell carcinoma: Retrospective evaluation of outcome

INTRODUCTION Photodynamic therapy (PDT) is a relatively new method of treating various kinds of pathologies. In this retrospective study, a total of 148 patients with basal cell carcinoma (BCC) were treated with surface illumination methyl aminolevulinate - photodynamic therapy (MAL-PDT) or meta-tetrahydroxyphenylchlorin (mTHPC-PDT). Comparisons with the clinical features, rate of recurrence and overall outcome were made. MATERIALS AND METHODS Surface illumination PDT was offered under local or general anaesthesia. For thin BCCs, the 16% strength cream (MAL) was applied topically 3h prior to tissue illumination. A single-channel 628nm diode laser was used for illumination and light was delivered at 100J/cm2 per site. For thick BCCs, 0.05mg/kg mTHPC was administered intravenously prior to tissue illumination. A single-channel 652nm diode laser was used for illumination and light was delivered at 20J/cm2 per site. Lesion response evaluation was carried out according to RECIST. RESULTS The MAL-PDT sub-group included 86 patients with 127 thin BCCs; 80 patients had complete response (CR) after one round of treatment. The mTHPC-PDT sub-group included 62 patients with 116 thick BCCs; 60 patients had complete response after one round of treatment. Statistically significant factors associated with complete response to MAL-PDT included superficial BCC histotype (P<0.001), ≤0.5mm tumour thickness (P<0.001) and lack of ulceration (P<0.001). While for the mTHPC-PDT sub-group, both superficial and nodular types responded significantly better than invasive type (P<0.001); the lack of ulceration was insignificant factor in achieving complete response. CONCLUSION PDT achieved high efficacy in the treatment of basal cell carcinomas with greatly reduced morbidity and disfigurement. The technique is simple, can commonly be carried out in outpatient clinics, and is highly acceptable to patients.