Local recurrence of tumor at sites of intervention in malignant pleural mesothelioma

A practical approach to the diagnosis and management of malignant pleural effusions in resource-constrained settings

No pleural intervention in a patient with confirmed malignant pleural effusion (MPE) prolongs life, but even the recommended interventions for diagnosis and palliation can be costly and therefore unavailable in large parts of the world. However, there is good evidence to guide clinicians working in low- and middle-income countries on the most cost-effective and clinically effective strategies for the diagnosis and management of MPE. Transthoracic ultrasound-guided closed pleural biopsy is a safe method of pleural biopsy with a diagnostic yield approaching that of thoracoscopy. With the use of pleural fluid cytology and ultrasound-guided biopsy, ≥90% of cases can be diagnosed. Cases with an associated mass lesion are best suited to an ultrasound-guided fine needle aspiration with/without core needle biopsy. Those with diffuse pleural thickening and/or nodularity should have an Abrams needle (<1 cm thickening) or core needle (≥1 cm thickening) biopsy of the area of interest. Those with insignificant pleural thickening should have an ultrasound-guided Abrams needle biopsy close to the diaphragm. The goals of management are to alleviate dyspnoea, prevent re-accumulation of the pleural effusion and minimise re-admissions to hospital. As the most cost-effective strategy, we suggest early use of indwelling pleural catheters with daily drainage for 14 days, followed by talc pleurodesis if the lung expands. The insertion of an intercostal drain with talc slurry is an alternative strategy which is noninferior to thoracoscopy with talc poudrage.

Educational aims

To provide clinicians practising in resource-constrained settings with a practical evidence-based approach to the diagnosis and management of malignant pleural effusions.To explain how to perform an ultrasound-guided closed pleural biopsy.To explain the cost-effective use of indwelling pleural catheters.

Incidence and Risk Factors of Chest Wall Metastasis at Biopsy Sites in Patients with Malignant Pleural Mesothelioma

To investigate the incidence and risk factors of chest wall metastasis (CWM) at biopsy sites in patients with malignant pleural mesothelioma (MPM). This retrospective cohort study was conducted in 262 consecutive MPM patients who underwent multimodal treatment in which including neoadjuvant chemotherapy (NAC) and curative-intent surgery, from August 2009 to March 2021. CWM was evaluated radiologically (r-CWM) and pathologically (p-CWM). We also investigated the risk factors of p-CWM and the consistency between r-CWM and p-CWM. Of 262 patients, 25 patients were excluded from analysis due to missing data or impossibility of evaluation. Of the eligible 237 patients, pleural biopsy was performed via video-assisted thoracoscopic surgery in 197 (83.1%) and medical thoracoscopy in 40 (16.9%). Pleurodesis was performed after pleural biopsy in 74 patients (31.2%). All patients received NAC followed by curative-intent surgery. Radiological examination showed r-CWM in 43 patients (18.1%), while pathological examination showed p-CWM in 135 patients (57.0%). The incidence of p-CWM was significantly higher in the patients who received pleurodesis after pleural biopsy (77.0% vs. 47.9%, <0.001). Multivariate logistic regression analysis for p-CWM revealed that pleurodesis is an independent risk factor of p-CWM (adjusted hazard ratio, 3.46; 95% confidence interval, 1.84−6.52, <0.001). CWM at the biopsy site was pathologically proven in more than half of the patients (57.0%) who received NAC followed by curative-intent surgery, which was higher than the numbers diagnosed by radiological examinations (p-CWM: 57.0% vs. r-CWM: 18.1%). Pleurodesis after pleural biopsy is an independent risk factor of p-CWM.

Ultrasound-guided interventional radiology procedures in the chest

Ultrasonography is a very good tool for guiding different interventional procedures in the chest. It is the ideal technique for managing conditions involving the pleural space, and it makes it possible to carry out procedures such as thoracocentesis, biopsies, or drainage. In the lungs, only lesions in contact with the costal pleura are accessible to ultrasound-guided interventions. In this type of lung lesions, ultrasound is as effective as computed tomography to guide interventional procedures, but the rate of complications and time required for the intervention are lower for ultrasound-guided procedures.

Prophylactic irradiation of tracts in patients with malignant pleural mesothelioma: A systematic review and meta-analysis of randomized trials

INTRODUCTION

The role of prophylactic irradiation of tracts (PIT) to prevent tumor seeding at the site of a diagnostic or therapeutic intervention in patients with malignant pleural mesothelioma (MPM) is controversial. This study aimed to determine the efficacy of PITs in preventing procedure tract metastases (PTM) after a chest wall procedure in MPM.

MATERIALS AND METHODS

We searched various databases from inception date to April 2020 for randomized controlled trials (RCTs) comparing PIT with no PIT in patients who had a chest wall procedure for MPM. We assessed the risk of bias of individual RCT using the RoB2 tool. The primary outcome was the occurrence of PTM. Meta-analysis was performed using random-effects model. We employed the GRADE approach to assess the certainty of the evidence.

RESULTS

We identified five RCTs including 737 patients. Two RCTs had a low risk of bias. PIT was associated with a significant reduction in the odds of PTM (odd ratio, 0.55; 95 % confidence interval, 0.32 to 0.95; P-value = 0.03; I² = 13 %; GRADE: moderate certainty). One RCT reported no difference in overall survival outcome with the use of PIT. None of the RCTs performed subgroup analyses. Sensitivity analyses showed similar results when limited to RCTs with low risk of bias.

CONCLUSION

PIT significantly reduces the occurrence of PTM in patients with MPM who had a diagnostic or therapeutic chest wall procedure.

Pleural mesothelioma: is the surgeon still there?

Malignant pleural mesothelioma (MPM) is a rare malignancy with some unique characteristics. Tumor biology is aggressive and prognosis is poor. Despite more knowledge on histology, tumor biology and staging, there is still a relevant discrepancy between clinical and pathologic staging resulting in difficult prediction of prognosis and treatment outcome, making treatment allocation more challenging than in most other malignancies. After years of nihilism in the late 80s, a period of activism started evaluating different treatment protocols combined with research driven mainly by academic centers; at the time, selection was based on histology and stage only. This period was important to gain knowledge about the disease. However, the interpretation of data was difficult since selection criteria and definitions varied substantially. Not surprisingly, until now there is no common agreement on best treatment even among specialists. Hence, a review of our current concepts is indicated and personalized treatment should become applicable in the future. Surgery was and still is an issue of debate. In principle, surgery is an effective approach as it allows macroscopic complete elimination of a tumor, which is relatively resistant to medical treatment. It helps to set the clock back and other therapies that have also just a limited effect can be applied sequentially before or after surgery. Furthermore, to date best long-term outcome is reported from surgical series in combination with other modalities. However, part of the community considers surgery associated with too high morbidity and mortality when balanced to the limited life expectancy. This criticism is understandable, since poor results after surgery are reported. The present article will review the indication for surgery and discuss the different procedures available for macroscopic complete resection-such as lung-preserving (extended) pleurectomy/decortication as well as extrapleural pneumonectomy to illustrate that 'The surgeon is still there!'

Prophylactic Irradiation of Tracts in Patients With Malignant Pleural Mesothelioma: An Open-Label, Multicenter, Phase III Randomized Trial

PURPOSE

Prophylactic irradiation to the chest wall after diagnostic or therapeutic procedures in patients with malignant pleural mesothelioma (MPM) has been a widespread practice across Europe, although the efficacy of this treatment is uncertain. In this study, we aimed to determine the efficacy of prophylactic radiotherapy in reducing the incidence of chest wall metastases (CWM) after a procedure in MPM.

METHODS

After undergoing a chest wall procedure, patients with MPM were randomly assigned to receive prophylactic radiotherapy (within 42 days of the procedure) or no radiotherapy. Open thoracotomies, needle biopsies, and indwelling pleural catheters were excluded. Prophylactic radiotherapy was delivered at a dose of 21 Gy in three fractions over three consecutive working days, using a single electron field adapted to maximize coverage of the tract from skin surface to pleura. The primary outcome was the incidence of CWM within 6 months from random assignment, assessed in the intention-to-treat population. Stratification factors included epithelioid histology and intention to give chemotherapy.

RESULTS

Between July 30, 2012, and December 12, 2015, 375 patients were recruited from 54 centers and randomly assigned to receive prophylactic radiotherapy (n = 186) or no prophylactic radiotherapy (n = 189). Participants were well matched at baseline. No significant difference was seen in the incidence of CWM at 6 months between the prophylactic radiotherapy and no radiotherapy groups (no. [%]: 6 [3.2] v 10 [5.3], respectively; odds ratio, 0.60; 95% CI, 0.17 to 1.86; P = .44). Skin toxicity was the most common radiotherapy-related adverse event in the prophylactic radiotherapy group, with 96 patients (51.6%) receiving grade 1; 19 (10.2%), grade 2; and 1 (0.5%) grade 3 radiation dermatitis (Common Terminology Criteria for Adverse Events, version 4.0).

CONCLUSION

There is no role for the routine use of prophylactic irradiation to chest wall procedure sites in patients with MPM.

Is there a role for prophylactic radiotherapy to intervention tract sites in patients with malignant pleural mesothelioma?

Malignant pleural mesothelioma has a high morbidity and poor prognosis. Most patients undergo invasive pleural interventions to either facilitate diagnosis and/or alleviate symptoms from malignant pleural effusion. Procedure tract metastasis (PTM) are a well-known complication of pleural procedures in mesothelioma and there has been longstanding debate regarding the role of prophylactic irradiation of tracts in preventing them. This review summarises the existing evidence surrounding this controversial topic. Despite initial discrepancies amongst the results of 3 small, historical trials regarding the efficacy of prophylactic radiotherapy in mesothelioma, two large randomised-control trials have recently provided more clarity. The SMART trial, which randomised over 200 patients, found no benefit of prophylactic radiotherapy in reducing PTM incidence in their primary analysis, with a number needed to treat (NNT) of 25.1 to prevent a single painful PTM. Additionally, there was no benefit in terms of symptomology, health-related quality of life parameters or cost-effectiveness. This is supported by the preliminary results of the Prophylactic Irradiation of Tracts in Patients with Pleural Mesothelioma (PIT) trial, which randomised 375 patients and also found no evidence that prophylactic radiotherapy reduced PTM incidence, although the full results are still awaited. Combined analysis of these trials is planned, which will help clarify whether specific subpopulations may derive benefit from prophylactic radiotherapy, such as patients not receiving chemotherapy. Based on the currently available evidence there is no role for routine delivery of prophylactic radiotherapy to prevent PTM in mesothelioma. Instead holistic and vigilant follow-up of patients is recommended, aiming for adequate palliation of symptoms and support for patients. Should painful nodules develop these can be effectively treated with subsequent palliative radiotherapy. After years of uncertainty and debate, recent international guidelines have consistently advised against the use of prophylactic irradiation of tracts based on contemporary high-quality evidence.

Combined hyaluronate-based films loaded with pemetrexed and cisplatin for the treatment of malignant pleural mesothelioma: Preliminary evaluation in an orthotopic tumor recurrence model

Malignant pleural mesothelioma (MPM) is a rare malignancy characterized by a long latency period of 20-50 years after exposure to the main aetiology agent that is asbestos. MPM treatments include surgery, chemotherapy, and radiation therapy, with the combination pemetrexed and cisplatin being the standard chemotherapy approach. Despite this multimodality therapy one of the major issues after surgery is the high rate of local recurrence of the tumor. One possible approach would be the intrapleural application of implants loaded with anticancer drug to be applied during surgery to prevent local tumor recurrence. The implant proposed in the present work is a polymeric film of hyaluronic acid loaded with pemetrexed. The film developed is a hydrophilic, thin and flexible film sufficiently resistant to be applied intrapleurally adhering to the mesothelial surface. The release of pemetrexed from the film was found to be complete within2 h in phosphate buffered saline. In an orthotopic model of mesothelioma recurrence in rats, pemetrexed loaded films showed the same antitumor efficacy of pemetrexed disodium solutions administered intravenously or intrapleurally, while when administered in combination with cisplatin-loaded hyaluronate film, the implants almost completely prevented tumor recurrence. The local administration of drug-loaded polymer implants appears an ideal chemotherapy strategy especially for patients in which surgery is already selected as a viable therapeutic option.

[Prophylactic radiotherapy in a single fraction of 10Gy at intervention pleural site in patient with malignant pleural mesothelioma: A retrospective monocentric cohort study]

PURPOSE

Prophylactic radiotherapy to prevent procedure-tracts metastases from malignant pleural mesothelioma remains controversial and clinical practice varies. The purpose was to assess the efficacy of local radiotherapy in a single fraction of 10Gy in preventing malignant seeding at intervention pleural site in patients with malignant pleural mesothelioma.

MATERIAL AND METHODS

This is a retrospective cohort study, including patients with histological confirmed malignant pleural mesothelioma treated by prophylactic irradiation to prevent interventional site metastases with a unique fraction of 10Gy with 6 to 18MeV, from January 1990 to December 2013 in the institut de cancérologie de Lorraine (Nancy, France).

RESULTS

Ninety-one patients were treated by irradiation in intervention site, involving 120 intervention pleural sites, 91 thoracoscopies, 17 thoracotomies with chest drain and 12 CT or ultrasound guided needle biopsies. The median follow-up was 7 months (interquartile between 3 and 15 months). The overall survival was 43.5% at 12 months. The local progression free survival was 43.7% at 12 month. The incidence of local recurrence was 8% at 12 months. The median interval from radiotherapy to local recurrence was 4 months (2; 32). No grade II or higher toxicity was observed.

CONCLUSION

Irradiation of pleural intervention sites with a single fraction of 10Gy is effective, well tolerated, simple, fast and cost effective.

Radiotherapy for the treatment of malignant pleural mesothelioma

Malignant pleural mesothelioma is an aggressive disease that continues to be associated with poor outcomes. Although, traditionally this disease is considered to be resistant to radiotherapy, more recent evidence suggests that radiotherapy can produce positive outcomes. Over the past 15 years, the development of new, highly conformal radiotherapy techniques, such as intensity-modulated radiation therapy (IMRT), has enabled investigators to optimise the delivery of high-dose radiotherapy to the whole of the hemithorax. Prospective single-arm trials have shown that the median survival of patients who have completed high-dose hemithoracic radiotherapy after extrapleural pneumonectomy could reach 23·9-39·4 months independent of the chemotherapeutic response, suggesting that IMRT could potentially have an intrinsic benefit to this subset of patients. These observations have led to a change in practice, with the introduction of adjuvant pleural IMRT after pleurectomy-decortication and the development of induction-accelerated hemithoracic IMRT followed by extrapleural pneumonectomy. This Review focuses on recent observations on the role of radiotherapy in the treatment of malignant pleural mesothelioma, with particular emphasis on the results of clinical trials that evaluate the role of high-dose hemithoracic radiotherapy.

Video assisted thoracoscopic and open chest surgery in diagnosis and treatment of malignant pleural diseases

Parenchymal cancers of lung, breast, gastrointestinal tract and ovaries as well as lymphomas and mesotheliomas are among the most common cancer types causing malignant effusions, though almost all tumour types have been reported to cause a malignant effusion. The prognosis heavily depends on patients' response to systemic therapy however, regardless of the causing pathology and histopathologic form, malignant pleural disease is normally associated with a poor prognosis. To date, there are not sufficient data to allow accurate predictions of survival that would facilitate decision making for managing patients with malignant pleural diseases. Interventions are directed towards drainage of the effusion and, when appropriate, concurrent or subsequent pleurodesis or establishing long-term drainage to prevent re-accumulation. The rate of re-accumulation of the pleural effusion, the patient's prognosis, and the severity of the patient's symptoms should guide the subsequent choice of therapy. In contemporary medicine, not many cancers have managed to generate as intense debates concerning treatment, as malignant pleural mesothelioma. The relative advantages of surgery, radiation, chemotherapy and any combination of the three are continuously reassessed and reconsidered, even though not always based on scientific evidence. The aim of surgery in mesothelioma may be prolongation of life, in addition to palliation of symptoms. Longer recovery periods from more extensive surgical procedures could be justified, in carefully selected patients. Surgical options include: Video assisted thoracoscopic (VATS) pleurodesis, VATS partial pleurectomy (VATS PP)-both parietal and visceral; open pleurectomy decortication (PD)-with an extended option (EPD) and extrapleural pneumonectomy (EPP). Current evidence implies that EPD can be performed reliably in specialised centres with good results, both in terms of mortality and survival; however, no operation has yet been shown to be beneficial in a prospective randomized controlled clinical trial.

Nanoparticle drug-delivery systems for peritoneal cancers: a case study of the design, characterization and development of the expansile nanoparticle

Nanoparticle (NP)-based drug-delivery systems are frequently employed to improve the intravenous administration of chemotherapy; however, few reports explore their application as an intraperitoneal therapy. We developed a pH-responsive expansile nanoparticle (eNP) specifically designed to leverage the intraperitoneal route of administration to treat intraperitoneal malignancies, such as mesothelioma, ovarian, and pancreatic carcinomatoses. This review describes the design, evaluation, and evolution of the eNP technology and, specifically, a Materials-Based Targeting paradigm that is unique among the many active- and passive-targeting strategies currently employed by NP-delivery systems. pH-responsive eNP swelling is responsible for the extended residence at the target tumor site as well as the subsequent improvement in tumoral drug delivery and efficacy observed with paclitaxel-loaded eNPs (PTX-eNPs) compared to the standard clinical formulation of paclitaxel, Taxol®. Superior PTX-eNP efficacy is demonstrated in two different orthotopic models of peritoneal cancer-mesothelioma and ovarian cancer; in a third model-of pancreatic cancer-PTX-eNPs demonstrated comparable efficacy to Taxol with reduced toxicity. Furthermore, the unique structural and responsive characteristics of eNPs enable them to be used in three additional treatment paradigms, including: treatment of lymphatic metastases in breast cancer; use as a highly fluorescent probe to visually guide the resection of peritoneal implants; and, in a two-step delivery paradigm for concentrating separately administered NP and drug at a target site. This case study serves as an important example of using the targeted disease-state's pathophysiology to inform the NP design as well as the method of use of the delivery system. WIREs Nanomed Nanobiotechnol 2017, 9:e1451. doi: 10.1002/wnan.1451 For further resources related to this article, please visit the WIREs website.

Protocol for the surgical and large bore procedures in malignant pleural mesothelioma and radiotherapy trial (SMART Trial): an RCT evaluating whether prophylactic radiotherapy reduces the incidence of procedure tract metastases

INTRODUCTION

Patients with malignant pleural mesothelioma (MPM) may develop painful 'procedure tract metastasis' (PTM) at the site of previous pleural interventions. Prophylactic radiotherapy has been used to minimise this complication; however, three small randomised trials have shown conflicting results regarding its effectiveness. The surgical and large bore procedures in malignant pleural mesothelioma and radiotherapy trial (SMART Trial) is a suitably powered, multicentre, randomised controlled trial, designed to evaluate the efficacy of prophylactic radiotherapy within 42 days of pleural instrumentation in preventing the development of PTM in MPM.

METHODS AND ANALYSIS

203 patients with a histocytologically proven diagnosis of MPM, who have undergone a large bore pleural intervention (thoracic surgery, large bore chest drain, indwelling pleural catheter or local anaesthetic thoracoscopy) in the previous 35 days, will be recruited from UK hospitals. Patients will be randomised (1:1) to receive immediate radiotherapy (21 Gy in 3 fractions over 3 working days within 42 days of the pleural intervention) or deferred radiotherapy (21 Gy in 3 fractions over 3 working days given if a PTM develops). Patients will be followed up for 12 months. The primary outcome measure is the rate of PTM until death or 12 months (whichever is sooner), as defined by the presence of a clinically palpable nodule of at least 1 cm diameter felt within 7 cm of the margins of the procedure site as confirmed by two assessors. Secondary outcome measures include chest pain, quality of life, analgaesic requirements, healthcare utilisation and safety (including radiotherapy toxicity).

ETHICS AND DISSEMINATION

The trial has received ethical approval from the Southampton B Research Ethics Committee (11/SC/0408). There is a Trial Steering Committee, including independent members and a patient and public representative. The trial results will be published in a peer-reviewed journal and presented at international conferences.

TRIAL REGISTRATION NUMBER

ISRCTN72767336.

Diagnostic accuracy of 18F-FDG-PET and PET/CT in the differential diagnosis between malignant and benign pleural lesions: a systematic review and meta-analysis

RATIONALE AND OBJECTIVES

To systematically review and meta-analyze published data about the diagnostic accuracy of fluorine-18-fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET) and PET/computed tomography (CT) in the differential diagnosis between malignant and benign pleural lesions.

METHODS AND MATERIALS

A comprehensive literature search of studies published through June 2013 regarding the diagnostic performance of (18)F-FDG-PET and PET/CT in the differential diagnosis of pleural lesions was carried out. All retrieved studies were reviewed and qualitatively analyzed. Pooled sensitivity, specificity, positive and negative likelihood ratio (LR+ and LR-) and diagnostic odds ratio (DOR) of (18)F-FDG-PET or PET/CT in the differential diagnosis of pleural lesions on a per-patient-based analysis were calculated. The area under the summary receiver operating characteristic curve (AUC) was calculated to measure the accuracy of these methods. Subanalyses considering device used (PET or PET/CT) were performed.

RESULTS

Sixteen studies including 745 patients were included in the systematic review. The meta-analysis of 11 selected studies provided the following results: sensitivity 95% (95% confidence interval [95%CI]: 92-97%), specificity 82% (95%CI: 76-88%), LR+ 5.3 (95%CI: 2.4-11.8), LR- 0.09 (95%CI: 0.05-0.14), DOR 74 (95%CI: 34-161). The AUC was 0.95. No significant improvement of the diagnostic accuracy considering PET/CT studies only was found.

CONCLUSIONS

(18)F-FDG-PET and PET/CT demonstrated to be accurate diagnostic imaging methods in the differential diagnosis between malignant and benign pleural lesions; nevertheless, possible sources of false-negative and false-positive results should be kept in mind.

Clinical indications and results after chest wall resection for recurrent mesothelioma

OBJECTIVE

The ipsilateral hemithorax is the most common site of recurrence after surgical resection for malignant pleural mesothelioma. Salvage treatment has generally been ineffective. We reviewed the outcomes after resection of isolated ipsilateral chest recurrence after cytoreductive surgery in patients with malignant pleural mesothelioma.

METHODS

Patients with malignant pleural mesothelioma who underwent initial surgical resection at our institution from 1988 to 2011 and were subsequently treated for localized recurrence with an additional chest resection were identified and their data retrospectively reviewed.

RESULTS

A total of 1142 patients underwent either extrapleural pneumonectomy (n = 794) or pleurectomy/decortication (n = 348). Of the patients who returned for follow-up, 47 (4.1%) had chest wall recurrence amenable to resection. The location of recurrence was predominantly incisional (49%) and/or costophrenic (38%). The median time to recurrence after either extrapleural pneumonectomy or pleurectomy/decortication was 16.1 months (range, 2.7-58.2). No 30-day mortality was found for chest wall resection, and the median length of stay in the hospital was 3 days (range, 0-12). The median overall survival duration after chest wall resection correlated positively with the time to recurrence (epithelial: median, 8.9, 17.2, and 35.8 months for a time to recurrence of <12, 12 to <24, and ≥24 months, respectively; biphasic: median, 2.7 and 15.9 months for a time to recurrence of <10 and ≥10 months, respectively).

CONCLUSIONS

Chest wall resection is a safe and effective therapeutic option in the management of localized chest wall recurrence of malignant pleural mesothelioma. The time to recurrence appears to be predictive of the expected survival benefit in both epithelial and biphasic malignant pleural mesothelioma.

Radiotherapy applications of patients with malignant mesothelioma: A single center experience

BACKGROUND

In the management of malignant pleural mesothelioma, radiotherapy has been used for the purpose of prophylaxis to reduce the incidence of recurrence at surgical insertion sites or palliate the symptoms.

AIM

The purpose of the study was to evaluate the techniques and effectiveness of radiotherapy in malignant pleural mesothelioma.

MATERIALS AND METHODS

Forty-four (18 female, 26 male) patients diagnosed with malignant pleural mesothelioma were retrospectively evaluated. All patients had surgery or thoracoscopic biopsy for diagnosis, staging or treatment and all received palliative or prophylactic radiotherapy. Fifty-seven percent of the patients received chemotherapy.

RESULTS

Prophylactic radiation was applied to 27 patients with 4-15 MeV electron energies. The median radiotherapy dose was 30 Gy with 3 Gy daily fraction dose. During treatment, 12 patients had grade 1 erythema according to the RTOG scale. In 3 (12%) patients, a local failure at treatment field was observed. Palliative radiotherapy was applied to 17 patients for pain palliation. The median radiation dose was 40 Gy with 2 Gy daily fraction dose by using 6-18 MV photon and/or 4-12 MeV electron energies. Two patients had grade 1 erythema and one patient had grade 2 odynophagy according to the RTOG scale. For 10 (59%) patients, palliation of chest pain was delivered. No late toxicity was observed for all cases.

CONCLUSION

Our experience showed that prophylactic and palliative radiotherapy are effective and safe therapy modalities in malignant pleural mesothelioma in preventing seeding metastasis at intervention sites or relieving pain. Prospective randomized studies are still needed to determine the benefits of radiotherapy application and to indicate optimum dose schemes.

Should all patients who have mesothelioma diagnosed by video-assisted thoracoscopic surgery have their intervention sites irradiated?

A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was whether patients diagnosed with mesothelioma by video-assisted thoracoscopic surgery should have their intervention sites irradiated to prevent metastatic seeding. Altogether 334 papers were found using the reported search, of which nine represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. There is no general consensus in the literature. Four studies recommend prophylactic irradiation therapy (PIT), while three studies stated that PIT was unnecessary. A systematic review identified only three suitable randomized controlled trials (RCTs) from the literature. One trial found that 23% of radiotherapy (RT) patients developed tract metastases compared to 10% of control patients (P=0.748) with an estimated hazard ratio (RT to control) of 1.28 (95% CI: 0.29-5.73). Time from procedure to tract metastases was in fact shorter in patients treated with RT (2.4 months RT vs. 6.4 months control, non-significant). Another trial found that seeding of metastatic tumour to the intervention site occurred in 7% of RT sites vs. 10% of control sites (P=0.53). Freedom from tract metastasis survival was also non-significant between RT and control arms (P=0.82). However, the third trial reported a significantly greater incidence of intervention site metastases in control vs. RT patients (40% vs. 0%, respectively, P<0.001). Non-randomised studies found mixed results. One reported that median survival between patients with and without local metastases was not significantly different (P=0.64) while another article described no local metastases in PIT sites. None of the studies reported significant skin or side reactions and treatment was generally well tolerated. Based on the available evidence, we conclude that PIT is not currently justified.

What is the role of radiotherapy in malignant pleural mesothelioma?

OBJECTIVE

A review of the evidence supporting the use of radiotherapy in patients with mesothelioma was performed.

METHODS

Relevant publications were searched for on Medline.

RESULTS

In a Medline search on radiotherapy and mesothelioma, 611 hits were obtained. A limited number of prospective phase II trials of radiotherapy as part of trimodality protocols for early disease and in the palliation of pain were found, along with three small randomized controlled trials of port-site prophylaxis.

CONCLUSION

No randomized data exist to support the use of radiotherapy after radical surgery, although there are a large number of publications describing its use as an integral part of therapy, including seven phase II studies. One ongoing trial is randomizing patients to radiotherapy or not after extrapleural pneumonectomy. None of these studies provided any assessment of radiotherapy independent of the other modalities investigated, nor did any formally assess intensity-modulated radiotherapy. There have been several reports of excessive toxicity with this technique, and its use should be limited to phase I studies until the basis of this toxicity is better understood. Three trials have looked at port-site prophylaxis, one supporting its use and two showing no evidence of benefit. Two studies addressed pain control prospectively, one showing definite but short-lived benefits. Implications. Radiotherapy is widely used in treating mesothelioma with little supporting evidence. More randomized trials are required to justify this use in all three common settings for its use.

Biopsy techniques for the diagnosis of mesothelioma

The incidence of mesothelioma continues to increase in the Western world and is likely to do so until 2011-2015. It commonly presents with breathlessness secondary to a pleural effusion, and whilst guidelines still advise thoracocentesis as the first line investigation, the sensitivity of this is low and a tissue diagnosis is usually required. Abrams needle biopsy also has a low diagnostic yield and high complication rate and is not recommended in guidelines on the investigation of mesothelioma. Computed tomography-guided biopsy or thoracoscopy both have a comparable sensitivity and low complication rates. Local anaesthetic thoracoscopy is increasingly used by respiratory physicians and has a comparable diagnostic sensitivity to Video-Assisted Thoracoscopic Surgery (VATS) without the need for a general anaesthetic. The requirement for prophylactic radiotherapy after pleural procedures in cases of mesothelioma is contentious, as the results from early trials suggesting it reduces tract seeding have been disputed by more recent trials.

Management of malignant pleural mesothelioma

Malignant pleural mesothelioma is a rare neoplasm arising from the surface serosal cells of the pleural cavity. More than 80% of cases of malignant pleural mesothelioma have been attributed to asbestos exposure. In its natural course median survival is 4 to 12 months. If untreated most of patients die due to local complications of the disease. Surgery improves local control but is not sufficient as a single treatment modality. The recommended treatment strategy for a select group of patients is multimodal therapy that includes surgery, radiotherapy and chemotherapy.

Prophylactic radiotherapy to intervention sites in mesothelioma: a systematic review and survey of UK practice

BACKGROUND AND PURPOSE

Patients with malignant pleural mesothelioma (MPM), who undergo chest instrumentation, may develop seeding at the site of intervention, leading to subcutaneous tumour. This is believed to be reduced by the common practice of prophylactic irradiation to intervention tracts (PIT). However, evidence to support PIT is currently inadequate and contentious.

MATERIALS AND METHODS

We carried out a systematic search of published literature for articles relating to the incidence of chest wall intervention tract metastases and the use of PIT in mesothelioma. In addition, a survey of current practice was conducted in 54 UK oncology centres.

RESULTS

Fourteen studies revealed an incidence of chest wall intervention tract metastases of 0-48% with a trend toward a higher rate of metastases for more invasive procedures. Three randomised controlled trials (RCTs), two prospective non-randomised studies and five retrospective series met the eligibility criteria to evaluate the role of PIT in MPM. Of the three RCTs, two did not support the use of PIT. None of the RCTs included patients who had received systemic chemotherapy. Of the oncology centres responding to the survey, 75% practiced PIT, and 80% would be interested in a trial to determine the efficacy of PIT.

CONCLUSIONS

No consensus has been reached to support the use of PIT. However, most centres in the UK still offer PIT. There was widespread interest in a randomised controlled trial to establish PIT efficacy in the era of effective systemic chemotherapy for malignant pleural mesothelioma.