Radiotherapy in Malignant Pleural Mesothelioma

Intensity-Modulated Radiation Therapy Improves the Target Coverage Over 3-D Planning While Meeting Lung Tolerance Doses for All Patients With Malignant Pleural Mesothelioma

PURPOSE

To investigate high conformality on target coverage and the ability on creating strict lung dose limitation of intensity-modulated radiation therapy in malignant pleural mesothelioma.

PATIENTS AND METHODS

Twenty-four radiation therapy plannings were evaluated and compared with dosimetric outcomes of conformal radiation therapy and intensity-modulated radiation therapy. Hemithoracal radiation therapy was performed on 12 patients with a fraction of 1.8 Gy to a total dose of 50.4 Gy. All organs at risk were contoured. Radiotherapy plannings were differed according to the technique; conformal radiation therapy was planned with conventionally combined photon-electron fields, and intensity-modulated radiation therapy was planned with 7 to 9 radiation beam angles optimized in inverse planning. Strict dose-volume constraints were applied.

RESULTS

Intensity-modulated radiation therapy was statistically superior in target coverage and dose homogeneity (intensity-modulated radiation therapy-planning target volume 95 mean 100%; 3-dimensional conformal radiation therapy-planning target volume 95 mean 71.29%, P = .0001; intensity-modulated radiation therapy-planning target volume 105 mean 11.14%; 3-dimensional conformal radiation therapy-planning target volume 105 mean 35.69%, P = .001). The dosimetric results of the remaining lung was below the limitations on intensity-modulated radiation therapy planning data (intensity-modulated radiation therapy-lung mean dose mean 7.5 [range: 5.6%-8.5%]; intensity-modulated radiation therapy-lung V5 mean 55.55% [range: 47%-59.9%]; intensity-modulated radiation therapy-lung V20 mean 4.5% [range: 0.5%-9.5%]; intensity-modulated radiation therapy-lung V13 mean 13.43% [range: 4.2%-22.9%]).

CONCLUSION

With a complex and large target volume of malignant pleural mesothelioma, intensity-modulated radiation therapy has the ability to deliver efficient tumoricidal radiation dose within the safe dose limits of the remaining lung tissue.

Protocol for PIT: a phase III trial of prophylactic irradiation of tracts in patients with malignant pleural mesothelioma following invasive chest wall intervention

INTRODUCTION

Histological diagnosis of malignant mesothelioma requires an invasive procedure such as CT-guided needle biopsy, thoracoscopy, video-assisted thorascopic surgery (VATs) or thoracotomy. These invasive procedures encourage tumour cell seeding at the intervention site and patients can develop tumour nodules within the chest wall. In an effort to prevent nodules developing, it has been widespread practice across Europe to irradiate intervention sites postprocedure--a practice known as prophylactic irradiation of tracts (PIT). To date there has not been a suitably powered randomised trial to determine whether PIT is effective at reducing the risk of chest wall nodule development.

METHODS AND ANALYSIS

In this multicentre phase III randomised controlled superiority trial, 374 patients who can receive radiotherapy within 42 days of a chest wall intervention will be randomised to receive PIT or no PIT. Patients will be randomised on a 1:1 basis. Radiotherapy in the PIT arm will be 21 Gy in three fractions. Subsequent chemotherapy is given at the clinicians' discretion. A reduction in the incidence of chest wall nodules from 15% to 5% in favour of radiotherapy 6 months after randomisation would be clinically significant. All patients will be followed up for up to 2 years with monthly telephone contact and at least four outpatient visits in the first year.

ETHICS AND DISSEMINATION

PIT was approved by NRES Committee North West-Greater Manchester West (REC reference 12/NW/0249) and recruitment is currently on-going, the last patient is expected to be randomised by the end of 2015. The analysis of the primary end point, incidence of chest wall nodules 6 months after randomisation, is expected to be published in 2016 in a peer reviewed journal and results will also be presented at scientific meetings and summary results published online. A follow-up analysis is expected to be published in 2018.

TRIAL REGISTRATION NUMBER

ISRCTN04240319; NCT01604005; Pre-results.

Designing hybrid onconase nanocarriers for mesothelioma therapy: a Taguchi orthogonal array and multivariate component driven analysis

Onconase (ONC) is a member of a ribonuclease superfamily that has cytostatic activity against malignant mesothelioma (MM). The objective of this investigation was to develop bovine serum albumin (BSA)-chitosan based hybrid nanoformulations for the efficient delivery of ONC to MM while minimizing the exposure to normal tissues. Taguchi orthogonal array L9 type design was used to formulate ONC loaded BSA nanocarriers (ONC-ANC) with a mean particle size of 15.78 ± 0.24 nm (ζ = -21.89 ± 0.11 mV). The ONC-ANC surface was hybridized using varying chitosan concentrations ranging between 0.100 and 0.175% w/v to form various ONC loaded hybrid nanocarriers (ONC-HNC). The obtained data set was analyzed by principal component analysis (PCA) and principal component regressions (PCR) to decode the effects of investigated design variables. PCA showed positive correlations between investigated design variables like BSA, ethanol dilution, and total ethanol with particle size and entrapment efficiency (EE) of formulated nanocarriers. PCR showed that the particle size depends on BSA, ethanol dilution, and total ethanol content, while EE was only influenced by BSA content. Further analysis of chitosan and TPP effects used for coating of ONC-ANC by PCR confirmed their positive impacts on the particle size, zeta potential, and prolongation of ONC release compared to uncoated ONC-ANC. PCR analysis of preliminary stability studies showed increase in the particle size and zeta potential at lower pH. However, particle size, zeta potential, and EE of developed HNC were below 63 nm, 31 mV, and 96%, respectively, indicating their stability under subjected buffer conditions. Out of the developed formulations, HNC showed enhanced inhibition of cell viability with lower IC50 against human MM-REN cells compared to ONC and ONC-ANC. This might be attributed to the better cell uptake of HNC, which was confirmed in the cell uptake fluorescence studies. These studies indicated that a developed nanotherapeutic approach might aid in reducing the therapeutic dose of ONC, minimizing adverse effects by limiting the exposure of ONC to normal tissues, and help in the development of new therapeutic forms and routes of administration.

[Helical tomotherapy in the treatment of malignant pleural mesothelioma: The impact of low doses on pulmonary and oesophageal toxicity]

PURPOSE

To evaluate the adjuvant treatment of malignant pleural mesothelioma by helical tomotherapy and the impact of low doses on esophageal and pulmonary toxicity.

PATIENTS AND METHODS

Between June 2007 and May 2011, 29 patients diagnosed with malignant pleural mesothelioma received adjuvant radiotherapy by helical tomotherapy. The median age was 63 years (34-72). Histologically, 83 % of patients had epithelioid malignant pleural mesothelioma. Clinically, 45 % of patients were T3 and 55 % N0. Eighty six percent of the patients were treated by extrapleural pneumonectomy and 35 % received neoadjuvant chemotherapy with platinum and pemetrexed. The median dose in the pneumonectomy cavity was 50Gy at 2Gy/fraction.

RESULTS

The mean follow-up was 2.3 years after diagnosis. Overall survival at 1 and 2 years was 65 and 36 % respectively. The median survival from diagnosis was 18 months. Median lung volumes receiving 2, 5, 10, 13, 15 and 20Gy (V2, V5, V10, V13, V15 and V20) were 100, 98, 52, 36, 19 and 5 %. The median of the mean remaining lung dose was 11Gy. Two patients died of pulmonary complications, three patients had grade 3 lung toxicity, while esophageal grade 3-4 toxicity was observed in three other patients. No significant impact of clinical characteristics and dosimetric parameters were found on pulmonary toxicity, however a V10≥50 %, a V15≥15 % and mean lung dose of 10Gy or more had a tendency to be predictive of pulmonary toxicity (P<0.1). Moreover, in our analysis, the mean lung dose seems to have a significant impact on esophageal toxicity (P=0.03) as well as low doses to the controlateral lung: V5, V10 and V13 (P<0.05).

CONCLUSION

Helical tomotherapy is a promising technique in the multimodality treatment of malignant pleural mesothelioma. Low doses received by the contralateral lung appear to be the limiting factor. A dosimetric comparison with volumetric modulated arctherapy techniques would be interesting in this setting.

Radiotherapy for the treatment of pain in malignant pleural mesothelioma: a systematic review

Radiotherapy is commonly used to treat pain in malignant pleural mesothelioma (MPM). The purpose of this systematic review is to examine the evidence for this practice. Medline (1946-2013), Embase (1974-2013) and Central (The Cochrane Library Issue 9, 2012) databases were searched. Eligible studies met the following criteria: MPM (histological or radiological diagnosis), radiotherapy given with the intent of improving pain, response rates to radiotherapy reported, dose and fractionation reported and the relationship between radiotherapy and pain response explored. All studies had independent review and were graded according to evidence level. Eight studies met the eligibility criteria. Two studies were prospective single arm phase II studies while the remainder were retrospective case series. All were graded as either Level 2 or Level 3 evidence. Due to marked heterogeneity among studies, quantitative synthesis of results was not possible. No high quality evidence currently exists to support radiotherapy in treating pain in MPM. Studies focusing on clear pain endpoints and improving target delineation are needed. Such studies should also use modern radiotherapy techniques and concentrate on dose escalation.

Phase II trial of neoadjuvant pemetrexed plus cisplatin followed by surgery and radiation in the treatment of pleural mesothelioma

Background

Malignant pleural mesothelioma is an aggressive tumor that has a poor prognosis and is resistant to unimodal approaches. Multimodal treatment has provided encouraging results.

Methods

Phase II, open-label study of the combination of chemotherapy (pemetrexed 500 mg/m²+cisplatin 75 mg/m² IV every 21 days × 3 cycles), followed by surgery (en-bloc extrapleural pneumonectomy, 3–8 weeks after chemotherapy) and hemithoracic radiation (total radiation beam 54 Gy, received 4–8 weeks post-surgery). The primary endpoint was event-free survival, defined as the time from enrollment to time of first observation of disease progression, death due to any cause, or early treatment discontinuation.

Results

Fifty-four treatment-naïve patients with T1-3 N0-2 malignant pleural mesothelioma were enrolled, 52 (96.3%) completed chemotherapy, 45 (83.3%) underwent surgery, 22 (40.7%) completed the whole treatment including 90-day post-radiation follow-up. The median event-free survival was 6.9 months (95%CI: 5.0-10.5), median overall survival was 15.5 months (95%CI 11.0-NA) while median time-to-tumor response was 4.8 months (95%CI: 2.5-8.0). Eighteen (33.3%) and 13 (24.1%) patients were still event-free after 1 and 2 years, respectively. The most common treatment-emergent adverse events were nausea (63.0%), anemia (51.9%) and hypertension (42.6%).

Following two cardiopulmonary radiation-related deaths the protocol was amended (21 [38.9%] patients were already enrolled in the study): the total radiation beam was reduced from 54 Gy to 50.4 Gy and a more accurate selection of patients was recommended.

Conclusions

The combination of pemetrexed plus cisplatin followed by surgery and hemithoracic radiation is feasible and has a manageable toxicity profile in carefully selected patients. It may be worthy of further investigation.

Trial registration

Clinicaltrial.com registrationID #NCT00087698.

A method to visualize the uncertainty of the prediction of radiobiological models

A method for quantitative visualization of the uncertainty in the predicted tumor control probability (TCP) and normal tissue complication probability (NTCP) in radiotherapy has been developed. Uncertainties of TCP and NTCP due to inter-individual variation of the underlying radiosensitivity parameters was simulated by sampling the prescribed dose from a uniform distribution and the radiosensitivity-parameters from a Gaussian distribution. The result is visualized as a scatter-plot superimposed to the population-based dose response curves using the prescribed dose as the common dosimetric variable. In addition, probability histograms are derived quantifying the probability of specific TCP- or NTCP-values for individual patients from the underlying population. The method is exemplified with a pleural mesothelioma case with the lung as organ at risk. A prescribed dose of 54 Gy together with radiosensitivity variations of 6% (tumor) and 10% (normal tissue) results in a TCP of 85% (range 68-94%, 90% confidence interval, CI) and an NTCP of 4% (range 3-6%, 90% CI), respectively. Increasing the radiosensitivity variation of the tumor to 15% and reducing the lung tolerance dose by 25% results in values of 84% (range 51-97%, 90% CI) for TCP and 9% (range 6-12%, 90% CI) for NTCP. Increasing the dose to 60 Gy leads to TCP- and NTCP-values of 93% (range 69-100%, 90% CI) and 12% (range 8-17%, 90% CI), respectively. The new method visualizes the uncertainty of TCP- and NTCP-values and hence of the therapeutic window. This can help the clinician to assess the treatment plan for the individual patient.

Serum concentration of integrin-linked kinase in malignant pleural mesothelioma and after asbestos exposure

OBJECTIVES

Integrin-linked kinase (ILK) is an intracellular protein implicated in chronic inflammation and neoplastic transformation. In a recently accomplished pilot study, we showed that ILK can be detected in the serum of patients with benign and malignant chest diseases, including malignant pleural mesothelioma (MPM). Interestingly, average serum ILK concentrations were 10 times higher in MPM patients when compared with the rest of the study population, and a diagnostic test solely based on serum ILK concentration could discriminate between MPM and non-MPM with considerable accuracy. This study aimed to investigate whether serum ILK concentration could also be used to discriminate between MPM and asbestos exposure only.

METHODS

Using a self-developed sandwich enzyme-linked immunosorbent assay, we measured serum ILK concentrations in 101 MPM patients, and 96 asbestos-exposed, but healthy insulation workers. Seventy-three MPM patients had an epitheloid subtype (72.3%), and 42 had a Stage I or II disease (41.6%).

RESULTS

When compared with asbestos-exposed individuals, MPM patients of all clinical stages had significantly higher (mean ± standard deviation, median) serum ILK concentrations (10.7 ± 13.6, median 7 ng/ml vs 3.1 ± 4.6, median 1.4 ng/ml; P < 0.001). Among MPM patients, the serum ILK concentration was significantly higher at advanced disease stages III + IV than at early stages I + II (13.7 ± 15.9, median 8.5 ng/ml vs 6.7 ± 7.8, median 3.5 ng/ml; P = 0.02). Using serum ILK to discriminate between MPM patients and asbestos-exposed individuals yielded an area under the curve of 0.69 (95% confidence interval 0.63-0.76). The corresponding sensitivity and specificity for a cut-off of 4.49 ng/ml ILK are 61.4 and 80.2%, respectively.

CONCLUSIONS

These data show significant differences between MPM patients and asbestos-exposed but healthy individuals concerning their serum ILK concentration. Furthermore, since ILK levels are increased in advanced MPM stages in comparison with early MPM stages, we suggest evaluating its potential use as a marker of disease progression in MPM.

SEOM guidelines for the treatment of malignant pleural mesothelioma

Mesothelioma is a rare malignant tumour. Asbestos is the principal aetiological agent of malignant pleural mesothelioma (MPM) (≈80% of cases). The incidence of MPM is still increasing and will peak within the next 10 years. There are three main histological types of MPM: epithelial (≈60%), sarcomatous and mixed. There is no standard approach for patients with MPM. Surgery (radical extra-pleural pneumonectomy or pleurectomy/decortication) may be part of the initial treatment for carefully selected patients, generally combined with neoadjuvant or adjuvant chemotherapy and/or adjuvant radiotherapy, and should only be performed by experienced thoracic surgeons as part of a multidisciplinary team. Radiotherapy could be used as prophylaxis to reduce the incidence of recurrence at sites of diagnoses or therapeutic instrument insertion, in a multimodal treatment to improve locoregional control and to palliate symptoms. Based on the better compliance of neoadjuvant chemotherapy, lower rate of surgical morbidity and the possibility to select the optimal patients to be submitted to surgery, a neoadjuvant strategy is a better option than adjuvant chemotherapy, although there is no standard optimal sequence and types of treatment for multimodal therapy. In patients with no resectable disease, chemotherapy is the best option with platinum and pemetrexed or raltitrexed. At this time there is no widely approved salvage therapy.

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.

ZDHHC8 knockdown enhances radiosensitivity and suppresses tumor growth in a mesothelioma mouse model

Mesothelioma is an aggressive tumor caused by asbestos exposure, the incidence of which is predicted to increase globally. The prognosis of patients with mesothelioma undergoing conventional therapy is poor. Radiation therapy for mesothelioma is of limited use because of the intrinsic radioresistance of tumor cells compared with surrounding normal tissue. Thus, a novel molecular-targeted radiosensitizing agent that enhances the radiosensitivity of mesothelioma cells is required to improve the therapeutic efficacy of radiation therapy. ZDHHC8 knockdown reduces cell survival and induces an impaired G(2) /M checkpoint after X-irradiation in HEK293 cells. In the present study, we further analyzed the effect of the combination of ZDHHC8 knockdown and X-irradiation and assessed its therapeutic efficacy in mesothelioma models. SiRNA-induced ZDHHC8 knockdown in 211H and H2052 mesothelioma cells significantly reduced cell survival after X-irradiation. In 211H cells treated with ZDHHC8 siRNA and X-irradiation, the G(2) /M checkpoint was impaired and there was an increase in the number of cells with micronuclei, as well as apoptotic cells, in vitro. In 211H tumor-bearing mice, ZDHHC8 siRNA and X-irradiation significantly suppressed tumor growth, whereas ZDHHC8 siRNA alone did not. Immunohistochemical analysis showed decreased cell proliferation and induction of apoptosis in tumors treated with ZDHHC8 siRNA and X-irradiation, but not with ZDHHC8 siRNA alone. These results suggest that ZDHHC8 knockdown with X-irradiation induces chromosomal instability and apoptosis through the impaired G(2) /M checkpoint. In conclusion, the combination of ZDHHC8 siRNA and X-irradiation has the potential to improve the therapeutic efficacy of radiation therapy for malignant mesothelioma.

PET-guided dose escalation tomotherapy in malignant pleural mesothelioma

PURPOSE

To test the feasibility of salvage radiotherapy using PET-guided helical tomotherapy in patients with progressive malignant pleural mesothelioma (MPM).

PATIENTS AND METHODS

A group of 12 consecutive MPM patients was treated with 56 Gy/25 fractions to the planning target volume (PTV); FDG-PET/CT simulation was always performed to include all positive lymph nodes and MPM infiltrations. Subsequently, a second group of 12 consecutive patients was treated with the same dose to the whole pleura adding a simultaneous integrated boost of 62.5 Gy to the FDG-PET/CT positive areas (BTV).

RESULTS

Good dosimetric results were obtained in both groups. No grade 3 (RTOG/EORTC) acute or late toxicities were reported in the first group, while 3 cases of grade 3 late pneumonitis were registered in the second group: the duration of symptoms was 2-10 weeks. Median overall survival was 8 months (1.2-50.5 months) and 20 months (4.3-33.8 months) from the beginning of radiotherapy, for groups I and II, respectively (p=0.19). A significant impact on local relapse from radiotherapy was seen (median time to local relapse: 8 vs 17 months; 1-year local relapse-free rate: 16% vs 81%, p=0.003).

CONCLUSIONS

The results of this pilot study support the planning of a phase III study of combined sequential chemoradiotherapy with dose escalation to BTV in patients not able to undergo resection.

Helical tomotherapy for resected malignant pleural mesothelioma: dosimetric evaluation and toxicity

This study evaluated adjuvant helical tomotherapy after extrapleural pneumonectomy ± neo-adjuvant chemotherapy in 24 patients with malignant pleural mesothelioma. Toxicity was judged acceptable despite 2 cases (8%) of suspected grade 5 pneumonitis. With a mean follow-up of 7 months, 5 patients had distant and 2 local and distant failure.

Mesothelioma at era of helical tomotherapy: results of two institutions in combining chemotherapy, surgery and radiotherapy

PURPOSE

There is a scarce clinical experience about adjuvant helical tomotherapy (HT) in patients affected by malignant pleural mesothelioma (MPM) even though it appears as a useful technique to treat complex volume as the pleural cavity, and seems to have better dose distribution than the "classic" intensity modulated radiotherapy (IMRT).

METHODS AND MATERIALS

Twenty-four patients received adjuvant radiotherapy (RT) by HT from August 1st, 2007 to December 1st, 2009 at Curie Institute (Paris) and René Gauducheau Cancer Center (Nantes). Thirteen patients had neoadjuvant chemotherapy. Extrapleural pleuropneumonectomy (EPP) was done in 23 patients. Median dose to PTV was 50Gy [48.7-55.9Gy] (2Gy/fraction). Acute and long term toxicities, disease free survival (DFS), overall survival (OS) and relapses are presented.

RESULTS

Average follow up after RT was 7 months. The disease was staged mostly as T2-T3, N1-N2. Nineteen patients had epithelial type histology. Most patients tolerated radiotherapy with grade 1-2 side effects: redness of the skin, light cough or dyspnea, fatigue, nausea and odynophagia, mild increase of the post-operative thoracic pain. Grade 3 pneumonitis was suspected in 2 patients. Two grade 5 pneumonitis were also suspected. Eleven patients had a follow up of more than 6 months and no long term side effects related with HT were noted. At 24 months, 51.8% of patients were free of disease. Thirty percent of patients relapsed, with 2 patients presenting local relapses. Two patients died from recurrence.

CONCLUSION

With limited follow up, HT has comparable toxicity to those observed with traditional IMRT. Higher radiation dose and good coverage results in excellent local control.

[Value of tomotherapy in malignant pleural mesothelioma: first clinical results]

INTRODUCTION

There is little clinical data about the place of helicoidal tomotherapy (HT) in the treatment of malignant pleural mesothelioma (MPM). This new form of intensity modulated radiotherapy (IMRT) has great theoretical advantages in large and complex volumes when compared to "traditional" forms of radiotherapy.

PATIENTS AND METHODS

Fourteen patients diagnosed with MPM received adjuvant radiotherapy by HT. The patients were treated at the Curie Institute and the René Gauducheau Centre, starting in August 12007. All patients had a complete initial staging, an extrapleural pneumonectomy (EPP), and a minimum follow-up of six months. The median dose prescribed to the surgical cavity was 50 Gy (48-54 Gy) in 2 Gy (1.80-2.07) fractions. High dose regions received concomitant 57 Gy (54-69 Gy) in 2.16 Gy (2.00-2.30 Gy) fractions.

RESULTS

Median follow-up was 12.6 months after ending HT. Seven patients received neoadjuvant chemotherapy (cisplatin or carboplatin, and pemetrexed). Eight patients were staged pT3 and five were staged pN1-2. HT was well tolerated. Two patients had suspected G5 radiation pneumonitis within 6 months of ending HT. Of the 12 patients who survived treatment, six relapsed (in average 5.1 months after HT): distant. Four relapses were distant; two relapses were both local and distant. Three patients died after their initial relapse. After initial diagnosis, the median survival was 18.4 months. A learning curve was observed in the optimization of the dosimetric parameters.

CONCLUSION

Helicoidal tomotherapy is a reliable, quite well tolerated, and efficient way of treating MPM patients after an EPP.

Detection of integrin-linked kinase in the serum of patients with malignant pleural mesothelioma

OBJECTIVE

Integrin-linked kinase, which is relevant to neoplastic transformation, is highly expressed in malignant pleural mesothelioma. Recently, detection of integrin-linked kinase in serum of patients with ovarian cancer has been reported. This study asks whether integrin-linked kinase can also be detected in serum of patients with malignant pleural mesothelioma and whether serum level has diagnostic or prognostic relevance for that disease.

METHODS

A sandwich enzyme-linked immunosorbent assay was designed to detect integrin-linked kinase and applied to serum samples from 46 patients with malignant pleural mesothelioma, 98 patients with other malignant chest disease, and 23 patients with benign chest disease. Integrin-linked kinase serum concentration and clinical data were correlated statistically.

RESULTS

Median serum integrin-linked kinase concentration was significantly higher in malignant pleural mesothelioma (8.89 ng/mL) than in other malignant chest disease (0.66 ng/mL) or benign chest disease (0.78 ng/mL, P < .001). There was no relevant correlation of serum integrin-linked kinase with cell lysis parameters (R(2) < 0.1). Serum integrin-linked kinase concentration greater than 2.48 ng/mL had diagnostic sensitivity of 80%, specificity of 95%, positive predictive value of 85.7%, negative predictive value of 92.7%, and overall accuracy of 91% for distinction between malignant pleural mesothelioma and other diseases. Serum integrin-linked kinase concentration in malignant pleural mesothelioma was independent of histologic subtype or asbestos exposure. There was no statistically significant impact of serum integrin-linked kinase concentration on prognosis.

CONCLUSIONS

Integrin-linked kinase can be detected in serum of patients with malignant pleural mesothelioma and may be a diagnostic marker for the disease.

Pleural malignancies

Pleural malignancies, primary or metastatic, portend a grim prognosis. In addition to the serious oncologic implications of a pleural malignancy, these tumors can be highly symptomatic. A malignant pleural effusion can cause dyspnea, secondary to lung compression, or even tension physiology from a hydrothorax under pressure. The need to palliate these effusions is a seemingly straightforward clinical scenario, but with nuances that can result in disastrous complications for the patient if not attended to appropriately. Solid pleural malignancies can cause great pain from chest wall invasion or can cause a myriad of morbid symptoms because of the invasion of thoracic structures, such as the heart, lungs, or esophagus. This article reviews pleural malignancies, the purely palliative treatments, and the treatments that are performed with definitive (curative) intent.

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.

Intensity-Modulated Radiation Therapy with Simultaneous Integrated Boost in Unresected Left-Sided Pleural Mesothelioma: A Case Report

A 77-year-old male patient with unresected malignant pleural mesothelioma, clinical stage T3N0M0 according to the New International Staging System for Diffuse Malignant Pleural Mesothelioma, received intensity-modulated radiotherapy (IMRT) with a simultaneous integrated boost (SIB) after 6 cycles of chemotherapy with cisplatin and pemetrexed. SIB-IMRT delivered 40.5 Gy (1.5 Gy/fraction) to the left pleura and 50 Gy (1.85 Gy/fraction) to the sites of macroscopic disease. Radiotherapy was well tolerated. Two months after the end of radiotherapy the patient showed grade 2 lung toxicity (febrile episodes accompanied by dry cough) that was successfully treated with steroid therapy. Local control lasted for 2 years after SIB-IMRT. Then the tumor recurred marginally to the radiation field and the patient underwent chemotherapy with pemetrexed. Three years from the diagnosis, the patient is alive and in good general condition. He only takes prednisone 5 mg/daily for exertional dyspnea. To the best of our knowledge this is the first reported use of SIB-IMRT in unresected malignant pleural mesothelioma. Considering the dosimetric advantages of SIB-IMRT and the clinical results observed in our patient, additional evaluation of this technique seems justified.