Does PDT have potential in the treatment of COVID 19 patients?

The corona virus pandemic has ignited a proliferation of research aimed at prevention of spread, early diagnosis and treatment. Coincidentally, in recent years the Yorkshire Laser Centre has been engaged in developing the methodology of applying PDT in chronic bronchiectasis. Our methodology is based on Methylene Blue (MB) mediated PDT used topically within the airway. The novelty of the method is the use of a nebulizer to deliver the photosensitizer. We suggest that our protocol and methodology could be modulated for use in respiratory infections of COVID -19.

A Surgical View of Photodynamic Therapy in Oncology: A Review

Clinical photodynamic therapy (PDT) has existed for over 30 years, and its scientific basis has been known and investigated for well over 100 years. The scientific foundation of PDT is solid and its application to cancer treatment for many common neoplastic lesions has been the subject of a huge number of clinical trials and observational studies. Yet its acceptance by many clinicians has suffered from its absence from the undergraduate and/or postgraduate education curricula of surgeons, physicians, and oncologists. Surgeons in a variety of specialties many with years of experience who are familiar with PDT bear witness in many thousands of publications to its safety and efficacy as well as to the unique role that it can play in the treatment of cancer with its targeting precision, its lack of collateral damage to healthy structures surrounding the treated lesions, and its usage within minimal access therapy. PDT is closely related to the fluorescence phenomenon used in photodiagnosis. This review aspires both to inform and to present the clinical aspect of PDT as seen by a surgeon.

Autofluorescence bronchoscopy in volunteer asymptomatic smokers

We assess the sensitivity of autofluorescence bronchoscopy (AFB) compared to that of white light bronchoscopy (WLB) for identification of pre-invasive neoplastic changes of bronchial mucosa in asymptomatic heavy smokers. WLB was performed using a standard flexible fibre-optic bronchoscope, and AFB carried out using the Xillix LIFE Lung((R)) system. Positive AFB images were indicated in the bronchial tree from 51 of the 93 subjects in the study. Biopsies showed epithelial abnormalities in 27 (15 metaplasia, 12 inflammatory changes) of these. WLB showed abnormality in 1 subject but with no pathological changes revealed by cyto-histology. Therefore, the sensitivity of AFB to metaplasia was 75% compared to zero for WLB. AFB yields positive predictive values for metaplastic and overall mucosal changes of 29.4% and 52.9%, respectively. In summary, over 16% of asymptomatic smokers had metaplastic changes in their bronchial mucosa, and AFB proved more sensitive in revealing early changes than WLB.

Place of cryotherapy, brachytherapy and photodynamic therapy in therapeutic bronchoscopy of lung cancers

Cryotherapy, brachytherapy and photodynamic therapy (PDT) are three different methods proposed in the endoluminal treatment of lung cancers. The current article presents an overview of the specific indications and limits of each technique. These three methods were first proposed with palliative intent in inoperable patients with centrally located lung cancers. Now, the best indication is a curative intent in early stage lung cancers. Of the three, cryotherapy is the cheapest method. It induces cell necrosis in a 3-mm radius around the probe, and is suitable for treatment of superficial tumours. However, clinical trials are limited. In contrast, many clinical studies have confirmed the efficacy of PDT in treatment of superficial lung cancers. Brachytherapy can cure more aggressive tumours with deeper invasion into the bronchial wall. Unfortunately, no comparative studies have been published. Each of these methods induces a delayed tumour necrosis, and thus neither is indicated in the treatment of obstructive tumours with acute dyspnoea. In many situations, these methods should be complementary, particularly cryotherapy and brachytherapy or PDT and brachytherapy. The combination of these endoscopic methods with chemotherapy should be widely tested to promote the adjuvant role of the endoscopic methods in the treatment of lung cancers.

Bronchoscopic NdYAG laser treatment in lung cancer, 30 years on: an institutional review

We review our 21-year experience in bronchoscopic NdYAG laser for lung cancer and the relevant literature. Patients totaling 1,159 received 2,235 bronchoscopic treatments. The pre-requisite for laser therapy was the presence of >50% obstruction of the bronchial lumen. We use the rigid bronchoscope, with the patient under general anaesthetic and application of laser in its non-contact mode. Two patients (0.17%) died following the procedure, and 4.8% had non-fatal complications. Four to 6 weeks after treatment there was a 48% increase in bronchial calibre and an increase of 27% (mean) in forced vital capacity and 15% (mean) in forced expiratory volume in one second, respectively. These paralleled symptomatic relief and chest X-ray improvement. Literature review indicated results similar to ours in those centres with high volume activity. Thirty years on, bronchoscopic YAG laser therapy of lung cancer still has an important role in palliation of patients with inoperable lung cancer, particularly those requiring immediate relief of bronchial obstruction.

Is bronchoscopic photodynamic therapy a therapeutic option in lung cancer?

This study addresses whether photodynamic therapy (PDT) is a valid therapeutic option in lung cancer treatment. A total of 24 articles were reviewed in two categories: advanced (G1) and early (G2) disease. Details considered included the following: 1) number of patients in each series; 2) staging; 3) methodology; 4) mortality; 5) morbidity; 6) survival; 7) relief of symptoms; and 8) concomitant treatments. G1 (636 patients) had severe endobronchial obstructive cancer and PDT was primarily for symptom relief. G2 (517 patients) had early stage cancer and were treated with PDT for curative intent. There was no procedure-related mortality in either group. G1 had a 5-28% incidence of skin sensitivity. Haemoptysis occurred in two series; one fatal, an incidence of 2.2%. Almost all patients had symptomatic relief. Patients with lower disease stage and better performance status had improved survival rates. G2 had a 8-28% incidence of sunburn. Three patients in one series (38 patients) had haemoptysis. Survival after 5 yrs in complete remission/response patients was 70%. This review suggests that bronchoscopic photodynamic therapy has indications in selected lung cancer patients with early or advanced stage disease. However, in the absence of a formal comparative study, no claim can be made of its superiority over other endobronchial therapies.

Photodynamic therapy (PDT) in esophageal cancer: a surgical view of its indications based on 14 years experience

The aim of this paper is to present the updated experience of the Yorkshire Laser Centre in PDT for esophageal cancer and to identify its role in specific subsets of patients. Also, in the light of this experience, to compare and contrast the results of PDT with appropriate subsets of patients treated in my esophageal surgery practice. 102 consecutive patients; 84 with advanced (Group A) and 18 with early (Group E) stage esophageal cancer undergoing endoscopic PDT were entered into a prospective study. Every patient had standard work up including clinical staging. PDT protocol was intravenous administration of Photofrin 2mg/kg body weight followed 24-72 hours later by endoscopic illumination using 630 nm laser light. Assessment of results was made on the basis of mortality, morbidity, patient satisfaction to treatment, symptom relief and survival. For comparison of PDT role with non PDT treated patients, reference is made to 3 previous publications comprising over 1100 patients [Moghissi, K., Br. J. Surg. 79, 935-937 (1992) (ref. 1); Sawant, D., Moghissi, K. Eur. J. Cardio-Thorac. Surg. 8, 113-117 (1994) (ref. 2); Sharpe, D. A. C., Moghissi, K. Eur. J. Cardiothorac. Surg. 10, 359-364 (1996) (ref. 3)]. There was no mortality associated with PDT. All patients expressed satisfaction to treatment. Post PDT complications consisted of photosensitivity skin reaction (sunburn) in 5 patients (5%) and esophageal stricture in 8 (8%) patients. Group A: There was significant symptom and dysphagia grade improvement. Mean survival was 9.5 months. Group E: There were no significant symptoms pre or post PDT and mean survival was 60.5 months. Comparison of PDT results in Group A with results of other palliative treatment methods, indicates that palliation can be achieved in all intraluminal cancer using PDT which is at least as good as other treatments. There is, in addition, advantage over other methods in patients with cervical esophageal cancer and in cases with re-growth of tumor obstructing previously placed stents. In early cases PDT appears capable of replicating surgical results in selected cases. PDT is an effective and safe treatment method in esophageal cancer. In advance disease it improves swallowing. In early stage disease it offers long survival and the prospect of cure in some patients. At present the role of PDT in early stage cancer should be limited to patients who are unsuitable for surgical resection. Therefore, PDT should be considered as a valid oncological option to be applied in selected cases.

Treatment of endotracheal or endobronchial obstruction by non-small cell lung cancer: lack of patients in an MRC randomized trial leaves key questions unanswered. Medical Research Council Lung Cancer Working Party

Symptoms of endotracheal or endobronchial obstruction caused by non-small cell lung cancer (NSCLC) may be relieved with external beam radiotherapy (XRT) or endobronchial treatment. The comparative roles of these two methods need to be established. Patients with predominantly intraluminal obstruction of the trachea, a main bronchus or a lobar bronchus by unresectable NSCLC were randomized to XRT versus the clinician's choice of endobronchial treatment with brachytherapy, laser resection or cryotherapy, according to local availability and practice. Clinicians' assessments included symptoms of obstruction, WHO performance status, lung function tests and adverse effects of treatment. Patients completed a Rotterdam Symptom Checklist at all assessments and a daily diary card to record the severity of major symptoms during the first 4 weeks. To show a difference of 15% in the relief of breathlessness rates at 4 months (from 65% to 80%), 400 patients were required. In spite of our many previously successful lung cancer trials, and initial interest from clinicians in 24 UK centres, who estimated they could randomize 200 patients per year into the present trial, only 75 patients were randomized from seven centres over 3.5 years. Intake to the trial was therefore abandoned in November 1996 although an independent Data Monitoring and Ethics Committee had concluded in April 1996 that the scientific case for the trial was still strong; there were no competing trials; there were no design problems; and much had been done to promote the trial. The main reasons given by centres for the slow intake were: lack of referrals of untreated patients; patients being referred specifically for endobronchial treatment; patients having already received XRT; emergency endobronchial relief of obstruction being necessary; and XRT and endobronchial treatment being considered complementary and not as alternatives. The relative advantages and disadvantages of XRT versus endobronchial treatment remain to be determined. The lack of recruitment to this trial raises the issue of innovative techniques not being given the chance of proving their worth compared with traditional treatments.

The role of photodynamic therapy (PDT) in inoperable oesophageal cancer

OBJECTIVE

To evaluate the role of PDT in palliation of patients with inoperable oesophageal cancer and to identify subgroups in which this role is of particular significance.

METHODS

Sixty-five patients (37 male, 28 female) aged 42-89 (mean 65.6) with advanced and inoperable oesophageal cancer were the subjects of this study. Inoperability was due to advanced stage of the disease in 61 and because of general condition in 4. Fifty-eight (89%) had previous treatments, other than PDT. All patients had dysphagia of whom 20 could not swallow fluid. Pre-PDT clinical, radiological and endoscopic examinations were carried out. Performance status (PS) and clinical staging was assessed. PDT protocol consisted of: intravenous injection of 2 mg/kg; photofrin (or equivalent polyhaematoporphyrin) followed 24-72 h later by endoscopic illumination using 630 nm laser light.

MAIN OUTCOME MEASUREMENTS

(1) Relief of dysphagia generally and specifically in those with cervical and post-cricoid carcinoma who were previously treated by external beam radiotherapy (EBR) (n=6) and those with previous intubation or stent (n=9); (2) Survival.

RESULTS

There was no PDT related mortality. Three patients (4.6%) developed a mild skin photosensitivity reaction. Dysphagia was relieved in all patients. The mean and median survival of the 58 patients who have died was 7. 7 and 6 months respectively. Seven patients are alive from 2-30 months (mean 16). Survival was not significantly influenced by tumour histology, location in the oesophagus, severity of dysphagia on admission, or by previous therapy. Survival was significantly influenced by Performance Status prior to treatment (P=0.03 log rank, for PS < or =2 vs. PS=3), an most significantly by the stage of the disease (P=0.0001 log rank, for Stage III vs. Stage IV).

CONCLUSIONS

(1) PDT is safe and effective for palliation of dysphagia in inoperable oesophageal cancer. This is particularly important in post-cricoid and cervical oesophageal cancer previously treated by other methods and for patients with recurrent malignant obstruction who previously had intubation or stent placement. (2) Survival is influenced by better PS (< or =2) and in those with disease Stage III rather than patients in Stage IV. This study has not been able to determine the influence of complete tumour staging on survival because, apart from four patients, all others were Stages III and IV cancer.

Tracheal resection and reconstruction: a review of 82 patients

OBJECTIVE

To assess early and long term (>5 years) results of tracheal resection and reconstruction.

PATIENTS AND METHODS

Eighty-two patients amongst 144 with a variety of tracheal lesions, undergoing resection and reconstruction referred to a single surgeon. A retrospective study, the patients were grouped into: Group 1 neoplastic (n = 55) subdivided into: primary tracheal malignancy (PTM, 16), secondary tracheal malignant (STM, 38), benign tracheal neoplasia (BTN, 1); 21 patients in this group had tracheal patch grafts made of Marlex mesh and pericardium; six had a bifurcation resection. Group 2 consisted of non-neoplastic (27) sub-divided into: post-intubation injuries (PII, 24) and traumatic or congenital fistula of the trachea (CTL, 3); 23 patients in this group had circumferential, and the remaining four had partial circumferential, excision of the trachea followed by reconstruction. One patient in this group had tracheal patch graft. Hospital mortality/morbidity, relief of symptoms, recurrence of lesions and long-term survival are considered.

RESULTS

Group 1: Five patients (9%) died in hospital; 12 patients, four (two with patch graft) in the PTM, seven (three with patch graft) in the STM group and one in the BTT group survived between 7 and 22 years, one patient is undergoing endoscopic laser. Group 2: There was one death 2 months after surgery. Two patients had recurrence of stricture, one requiring T tube stent, the other endoscopic laser therapy; 24 patients (one with patch graft) remain well between 7 and 22 years.

CONCLUSION

Tracheal resection and reconstruction is attended by good functional results. The long-term outcome for malignant disease relates to the histology and tumour staging. Patch grafting using a composite prosthesis of Marlex mesh and pericardium has a chance of long-lasting success when used in selected patients.

The place of bronchoscopic photodynamic therapy in advanced unresectable lung cancer: experience of 100 cases

OBJECTIVES

The objectives of the study were: (1) to evaluate effectiveness of photodynamic therapy (PDT) for symptom palliation in patients with inoperable lung cancer; (2) to determine survival benefit in a subset of patients.

METHODS

One hundred patients, 68 male, 32 female, aged 44-81 years (mean 62.5) with advanced inoperable bronchogenic cancer and endobronchial luminal obstruction were prospectively studied. Eighty-two percent had previous chemo/radiotherapy. The pre-treatment protocol consisted of: clinical, radiological and bronchoscopic examination, pulmonary function testing, assessment of WHO performance status and clinical staging. Treatment protocol was: intravenous injection of 2 mg/kg body weight of photofrin/polyhaematoporphyrin and interstitial illumination using 630 nm laser light 24-72 h later. Follow-up was at 6-8 weeks for 1 year. Then every 3-6 months if applicable. Repeat PDT as necessary.

RESULTS

All patients were stage IIIa-IV. The histology of the tumour was: non small cell in 90 and small cell in 10. There was no treatment related mortality. Mean endoluminal obstruction fell from 85.8% to 17.5%, mean forced vital capacity (FVC) and forced expiratory volume in 1s (FEVI) improvement was 430 ml and 280 ml, respectively. Ninety patients died from 6 weeks to 37 months, mean and median survival: 9 months and 5 months, respectively. Ten patients are alive from 13 to 72 months, mean 36 months, median 29 months. Overall 2-year survival was 19%. Multivariant analysis indicated that age, sex, histology and stage of disease did not influence survival significantly but performance status did. Patients with WHO < 2 had mean and median survival of 17.8 and 14 months versus WHO > 2, 6.9 mean and 4 months median survival (log-rank P < 0.0001).

CONCLUSIONS

(1) PDT is effective in palliation of inoperable advanced lung cancer. (2) Subset of patients with a better performance status have added survival benefit.

Historical prospective cohort study of the recurrence of pain after discontinuation of treatment with danazol or a gonadotropin-releasing hormone agonist

OBJECTIVE

To determine the duration of time to the recurrence of pain attributable to endometriosis after the discontinuation of treatment with danazol or a GnRH agonist (GnRH-a) in patients who have had a satisfactory response to the treatment.

DESIGN

Retrospective study.

SETTING

Nine academic medical centers in three countries.

PATIENT(S)

Three hundred twenty-seven women with diagnosed and staged endometriosis who were treated with at least 6 months of danazol or a GnRH-a and who experienced significant pain relief with therapy.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Duration of pain relief after completion of treatment as determined by a patient-initiated report of pain recurrence or increase in pain severity requiring intervention.

RESULT(S)

The median time to the recurrence of pain was 6.1 months for patients treated with danazol and 5.2 months for patients treated with a GnRH-a.

CONCLUSION(S)

Although there was a lack of uniformity in treatment effects across sites, the analyses have taken into account major covariant effects. The time to the recurrence of endometriosis-associated pain after danazol treatment was slightly longer than that after GnRH-a treatment.

Endoscopic laser therapy in malignant tracheobronchial obstruction using sequential Nd YAG laser and photodynamic therapy

BACKGROUND

Because the survival after treatment of advanced inoperable endo-tracheobronchial carcinoma is so poor, a pilot study was undertaken to evaluate the combined cumulative effect on survival of neodymium yttrium aluminium garnet (Nd YAG) laser followed by photodynamic treatment used endoscopically.

METHODS

Seventeen patients who presented between January 1992 and March 1996 with inoperable tracheobronchial lesions causing more than 50% endoluminal obstruction were selected to enter the pilot study. Initially they had bronchoscopic Nd YAG laser treatment to debulk the tumour, and this was followed six weeks later by photodynamic therapy to treat the residual tumour.

RESULTS

All patients had symptomatic relief and at least a partial response, and seven had a complete response for 3-6 months. Eight of the 17 (47%) survived for at least two years and 11 (65%) survived for a year or more. The median survival of the 10 patients who had died by the time of writing was 18.5 months (range 5-39), 95% confidence interval (CI) 9.9 to 29.5.

CONCLUSIONS

Combined Nd YAG laser and endoscopic photodynamic therapy may be an effective palliative treatment for patients with inoperable endotracheobronchial cancer.

The role of post-operative radiotherapy in non-small-cell lung cancer: a multicentre randomised trial in patients with pathologically staged T1-2, N1-2, M0 disease. Medical Research Council Lung Cancer Working Party

The role of post-operative radiotherapy for patients with non-small-cell lung cancer (NSCLC) is unclear despite five previous randomised trials. One deficiency with these trials was that they did not include adequate TNM staging, and so the present randomised trial was designed to compare surgery alone (S) with surgery plus post-operative radiotherapy (SR) in patients with pathologically staged T1-2, N1-2. M0 NSCLC. Between July 1986 and October 1993, 308 patients (154 S, 154 SR) were entered from 16 centres in the UK. The median age of the patients was 62 years, 74% were male, > 85% had normal or near normal levels of general condition, activity and breathlessness, 68% had squamous carcinoma, 52% had had a pneumonectomy, 63% had N1 disease and 37% N2 disease. SR patients received 40 Gy in 15 fractions starting 4-6 weeks post-operatively. Overall there was no advantage to either group in terms of survival, although definite local recurrence and bony metastases appeared less frequently and later in the SR group. In a subgroup analysis, in the N1 group no differences between the treatment groups were seen, but in the N2 group SR patients appeared to gain a one month survival advantage, delayed time to local recurrence and time to appearance of the bone metastases. There is, therefore, no clear indication for post-operative radiotherapy in N1 disease, but the question remains unresolved in N2 disease.

Resectional surgery in carcinoma of the oesophagus and cardia: what influences long-term survival?

OBJECTIVE

Our objectives were to determine factors which influence survival after resectional surgery in patients with cancer of the oesophagus and cardia.

PATIENTS AND METHOD

562 consecutive patients with primary cancer of the oesophagus or gastric cardia (oesophago-gastric junction) undergoing resectional surgery and reconstruction of the oesophagus were studied. Operative approach depended on tumour location, the aim being complete resection of the tumour and associated lymph nodes. Postoperative staging was based on tumour, nodes and metastasis (TNM) classification.

RESULTS

There were 342 males and 220 females, aged 61.8 +/- 12.8 years. Histology of the tumours was: squamous cell carcinoma 49%, adenocarcinoma 47.5% and other tumours 3.5%. The location of tumours within the oesophagus was: cervical (n = 32), upper thoracic (n = 18), middle thoracic (n = 241) and lower thoracic and gastric cardia (n = 271). Of the tumours 16% were stage I, 10% stage II and 74% stage III. Hospital mortality rate was 9% overall, significantly higher in cervical tumours (cervical tumours versus lower and or middle oesophageal tumours: P < 0.05), the elderly (age > 75 years versus age < 75 years: P < 0.05) and stage III disease (stage III versus stage I: P < 0.001). The overall 5-year survival rate was 18%. There was no correlation between tumour histology, location or type of operation and long-term survival. Survival disease-free for 5 years or more was 73% for stage I, 15.8% for stage II and 6% for stage III. The only significant correlation was between the stage of disease and long-term survival (stage I versus stage III P < 0.001, stage I versus stage II P < 0.05).

CONCLUSIONS

Immediate results are affected by a number of factors but long-term survival is related entirely to the stage of the tumour.