Pleurectomy and intraoperative brachytherapy and postoperative radiation in the treatment of malignant pleural mesothelioma

A Phase I Trial of Surgical Resection and Intraoperative Hyperthermic Cisplatin and Gemcitabine for Pleural Mesothelioma

INTRODUCTION

The primary objective of this single-institution phase I clinical trial was to establish the maximum tolerated dose of gemcitabine added to cisplatin and delivered as heated intraoperative chemotherapy after resection of malignant pleural mesothelioma.

METHODS

The extrapleural pneumonectomy (EPP) and pleurectomy/decortication (P/D) treatment arms were based on investigators' assessment of patient fitness and potential for macroscopic complete resection. Previously established intracavitary dosing of cisplatin (range 175-225 mg/m²) with systemic cytoprotection was used in combination with escalating doses of gemcitabine, following a 3-plus-3 design from 100 mg/m² in 100-mg increments.

RESULTS

From 2007 to 2011, 141 patients were enrolled and 104 completed treatment. The median age of those completing treatment was 65 years (range 43-85 years), and 22 (21%) were female. In the EPP arm (n = 59), 31 patients (53%) had the epithelioid histologic type and the median radiographic tumor volume was 236 cm³ (range 16-4285 cm³). In the P/D arm (n = 41), 29 patients (71%) had the epithelioid histologic type and the median tumor volume was 79 cm³ (range 6-1107 cm³). The operative mortality rate was 2%, and 35 and 22 serious adverse events were encountered among 27 patients (46%) and 16 patients (39%) in the EPP and P/D arms, respectively. Dose-limiting toxicity (grade 3 leukopenia) was observed in two patients who were receiving 1100 mg/m² of gemcitabine, thus establishing the maximum tolerated dose at 1000 mg/m², in combination with 175 mg/m² of cisplatin. The median overall and recurrence-free survival times in treated patients were 20.3 and 10.7 months, respectively.

CONCLUSIONS

Combination cisplatin and gemcitabine heated intraoperative chemotherapy can be administered safely and feasibly in the context of complete surgical resection of malignant pleural mesothelioma by EPP or P/D.

Treatment of Malignant Pleural Mesothelioma: American Society of Clinical Oncology Clinical Practice Guideline

Purpose To provide evidence-based recommendations to practicing physicians and others on the management of malignant pleural mesothelioma. Methods ASCO convened an Expert Panel of medical oncology, thoracic surgery, radiation oncology, pulmonary, pathology, imaging, and advocacy experts to conduct a literature search, which included systematic reviews, meta-analyses, randomized controlled trials, and prospective and retrospective comparative observational studies published from 1990 through 2017. Outcomes of interest included survival, disease-free or recurrence-free survival, and quality of life. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations. Results The literature search identified 222 relevant studies to inform the evidence base for this guideline. Recommendations Evidence-based recommendations were developed for diagnosis, staging, chemotherapy, surgical cytoreduction, radiation therapy, and multimodality therapy in patients with malignant pleural mesothelioma. Additional information is available at www.asco.org/thoracic-cancer-guidelines and www.asco.org/guidelineswiki .

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.

Multimodality therapy for malignant pleural mesothelioma: surgery plus chemoradiotherapy?

Malignant pleural mesothelioma, well known for its association with asbestos exposure, is an aggressive cancer of the pleura with poor prognosis if left untreated. There is no defined standard of care, but with curative surgery-based multimodality therapy, long-term survival has been documented. In addition to radiation and/or chemotherapy, multimodality therapy includes one of two operations (extrapleural pneumonectomy or radical pleurectomy/decortication) performed with the goal of resecting all gross disease. Ongoing trials are evaluating various treatment strategies involving radical resection, chemotherapy, radiation, intracavitary chemotherapy, photodynamic therapy and immunologic/biologic agents. Improvement in early diagnosis, targeted treatment and adjuvant therapy to control micrometastatic disease are needed to improve outcomes for patients with this challenging disease.

Surgical treatment of malignant pleural mesothelioma

Malignant Pleural Mesothelioma (MPM) remains a rare and lethal disease that is directly related to asbestos exposure in the vast majority of cases. While the total number of cases remains low compared to other malignancies, the worldwide incidence is expected to increase over the next twenty years. Currently, survival rates remain dismal and there is no standard therapy or consensus regarding treatment. However, over the last fifteen years there have been substantial improvements in the diagnosis and treatment of MPM, including easier and more accurate diagnostic techniques, improved methods of staging, more effective systemic therapy, a remarkable decrease in operative mortality, marked improvements in local control with adjuvant therapy, and perhaps most important, an emphasis on multidisciplinary care and multimodality clinical trials. Despite these advances, optimal therapy for these patients remains highly controversial and the role of surgery is actively debated. Most controversy centers on whether surgery increases survival and whether a survival benefit is best achieved with extrapleural pneumonectomy or pleurectomy/decortication within a multimodal regimen. To date, trimodality therapy that includes surgery, chemotherapy, and radiation offers the best survival advantage. It is generally accepted that the main goals of surgery, within the framework of a multimodality approach, is not only complete resection if possible, but more realistically, the resection of all macroscopic disease as an adjunct to the delivery of chemotherapy and radiation. The surgical options available to obtain this goal include extrapleural pneumonectomy (EPP) and pleurectomy/decortication (P/D). There are no randomized trials directly comparing EPP and P/D and the level of evidence supporting either technique remains low. Ultimately, the choice of operation depends on multiple factors including: disease stage, the patient's cardiopulmonary reserve, surgeon experience and philosophy, and the extent of planned adjuvant therapy. Yet, despite the inherent biases in most studies, the data thus far illustrates significant survival advantages with both P/D and EPP and surgeons should consider these approaches in select patients.

Quantitative measurement of lung reexpansion in malignant pleural mesothelioma patients undergoing pleurectomy/decortication

RATIONALE AND OBJECTIVES

Malignant pleural mesothelioma (MPM) is a neoplasm that grows circumferentially along the pleura. The tumor and concurrent pleural effusion may reduce lung function by restricting or preventing lung expansion. The purpose of this study was to provide objective evidence that pleurectomy/decortication (P/D) allows trapped lung to reexpand, quantify the reexpansion based on computed tomography (CT) scans, and investigate whether the expansion persists after surgery.

MATERIALS AND METHODS

A database of 12 patients demonstrating unilateral MPM was collected. Each patient underwent a presurgical CT scan, surgical debulking by P/D, and two postsurgical CT scans (at 1 and 4 months). The lung volume was measured in each scan using an automated algorithm and compared for each patient across time.

RESULTS

An increase in the ipsilateral postsurgical lung volume was observed for 10 of 12 patients (83%) 1 month after surgery. The median ipsilateral volume increase was 44% relative to the presurgical ipsilateral volume and 21% relative to the contralateral volume. A statistically significant change in ipsilateral lung volume was not observed between 1‑month and 4‑month postsurgical scans, implying that the volume improvement persisted months after surgery.

CONCLUSIONS

Debulking of MPM with P/D substantially increased the ipsilateral lung volume relative to both the presurgical ipsilateral volume and the contralateral lung volume. This improvement persisted months after surgery.

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.

Surgical therapy of mesothelioma

The treatment of malignant pleural mesothelioma is controversial, particularly regarding the role of surgery. Though well accepted as a diagnostic modality, surgery is also frequently used to establish stage, provide palliation, and perhaps most controversially, to offer cytoreduction with the putative goal of delaying tumor progression and prolonging survival. Pleurectomy/decortication (PD) can achieve macroscopic complete resection; however, the ability to deliver effective postoperative radiation treatment is limited because of the risk of lung toxicity. Accordingly, it has been associated with higher rates of local recurrence compared to extrapleural pneumonectomy (EPP). Extrapleural pneumonectomy generally offers a more complete cytoreduction compared to PD but at the cost of increased morbidity and mortality. Adjuvant hemithoracic radiation is feasible following EPP and in most series local recurrence rates are lower after EPP than PD. There are no convincing data, however, to show that one procedure is superior to the other in terms of survival. Furthermore, no randomized data currently exist that demonstrate a survival benefit to any form of surgical cytoreduction over systemic treatment and supportive care. If cytoreductive surgery does have a beneficial effect on long-term survival, it will most likely be realized in patients with epithelioid tumors without nodal metastases.

Volumetric modulation arc radiotherapy compared with static gantry intensity-modulated radiotherapy for malignant pleural mesothelioma tumor: a feasibility study

PURPOSE

A planning study was performed to evaluate RapidArc (RA), a volumetric modulated arc technique, on malignant pleural mesothelioma. The benchmark was conventional fixed-field intensity-modulated radiotherapy (IMRT).

METHODS AND MATERIALS

The computed tomography data sets of 6 patients were included. The plans for IMRT with nine fixed beams were compared against double-modulated arcs with a single isocenter. All plans were optimized for 15-MV photon beams. The dose prescription was 54 Gy to the planning target volume. The planning objectives for the planning target volume were a minimal dose of >95% and maximal dose of <107%. For the organs at risk, the parameters were as follows: contralateral lung, percentage of volume receiving 5 Gy (V(5 Gy)) <60%, V(20 Gy) < 10%, mean <10.0 Gy; liver, V(30 Gy) <33%, mean <31 Gy; heart, V(45 Gy) <30%, V(50 Gy) <20%, dose received by 1% of the volume (D(1%)) <60 Gy; contralateral kidney, V(15 Gy) <20%; spine, D(1%) <45 Gy; esophagus, V(55 Gy) <30%; and spleen, V(40 Gy) <50%. The monitor units (MUs) and delivery time were scored to measure the treatment efficiency. The pretreatment portal dosimetry scored delivery to the calculation agreement with the Gamma Agreement Index.

RESULTS

RA and IMRT provided equivalent coverage and homogeneity. Both techniques fulfilled objectives on organs at risk with a tendency of RA to improve sparing. The conformity index was 1.9 +/- 0.1 for RA and IMRT. The number of MU/2 Gy was 734 +/- 82 for RA and 2,195 +/- 317 for IMRT. The planning vs. delivery agreement revealed a Gamma Agreement Index for IMRT of 96.0% +/- 2.6% and for RA of 95.7% +/- 1.5%. The treatment time was 3.7 +/- 0.3 min for RA and 13.4 +/- 0.1 min for IMRT.

CONCLUSION

RA demonstrated compared with conventional IMRT, similar target coverage and better dose sparing to the organs at risks. The number of MUs and the time required to deliver a 2-Gy fraction were much lower for RA, allowing the possibility to incorporate this technique in the treatment options for mesothelioma patients.

Nael Martini: a leader in thoracic surgical oncology

Nael Martini was one of the leading academic general thoracic surgeons of the late 20th century. His most notable contributions related to the surgical and multimodality treatment of lung cancer.

Radiation therapy options for malignant pleural mesothelioma

The role of radiation therapy (RT) in the curative treatment of malignant pleural mesothelioma remains undefined. No data clearly support treatment of unresected mesothelioma with definitive RT. Early reports showed that RT was associated with unacceptable toxicity, but recent limited data suggest that treatment with intensity-modulated radiation therapy (IMRT) may be tolerable. Adjuvant RT after pleurectomy is also challenging, and similarly, no clear efficacy has been demonstrated. Some approaches, such as IMRT to the circumferential pleural envelope, appear feasible, but the fact that this approach does not address the disease in the fissures is problematic. The best setting in which to deliver RT is after extrapleural pneumonectomy, but the large and irregular target volume and multiple and adjacent sensitive normal structures make this complex. The Memorial Sloan-Kettering Cancer Center matched photon/electron technique is associated with acceptable efficacy and toxicity, but is limited in that it does not achieve complete coverage of the target volume to the prescription dose. The best dosimetry is achieved using IMRT, and this approach is the most promising to date. However, the toxicity profile can be severe, and the relevant predictive factors for complications are not fully understood. For these reasons, physicians should exercise caution, and IMRT after extrapleural pneumonectomy is probably best offered only by experienced teams or on protocol until further data have been gathered. New techniques such as helical tomotherapy and/or IMRT with the addition of electrons may also have a role in future treatment. RT can palliate symptoms provided the disease is confined to a tolerable radiation field.

Compensator-based intensity-modulated radiation therapy for malignant pleural mesothelioma post extrapleural pneumonectomy

The present work investigated the potential of compensator‐based intensity‐modulated radiation therapy (CB‐IMRT) as an alternative to multileaf collimator (MLC)–based intensity‐modulated radiation therapy (IMRT) to treat malignant pleural mesothelioma (MPM) post extrapleural pneumonectomy.

Treatment plans for 4 right‐sided and 1 left‐sided MPM post‐surgery cases were generated using a commercial treatment planning system, XIO/CMS (Computerized Medical Systems, St. Louis, MO). We used a 7‐gantry‐angle arrangement with 6 MV beams to generate these plans. The maximum required field size was 30×40 cm. We evaluated IMRT plans with brass compensators (•Decimal, Sanford, FL) by examining isodose distributions, dose–volume histograms, metrics to quantify conformal plan quality, and homogeneity. Quality assurance was performed for one of the compensator plans.

Conformal dose distributions were achieved with CB‐IMRT for all 5 cases, the average planning target volume (PTV) coverage being 95.1% of the PTV volume receiving the full prescription dose. The average lung V20 (volume of lung receiving 20 Gy) was 1.8%, the mean lung dose was 6.7 Gy, and the average contralateral kidney V15 was 0.6%. The average liver dose V30 was 34.0% for the right‐sided cases and 10% for the left‐sided case. The average monitor units (MUs) per fraction were 980 MUs for the 45‐Gy prescriptions (mean: 50 Gy) and 1083 MUs for the 50‐Gy prescriptions (mean: 54 Gy).

Post surgery, CB‐IMRT for MPM is a feasible IMRT technique for treatment with a single isocenter. Compensator plans achieved dose objectives and were safely delivered on a Siemens Oncor machine (Siemens Medical Solutions, Malvern, PA). These plans showed acceptably conformal dose distributions as confirmed by multiple measurement techniques. Not all linear accelerators can deliver large‐field MLC‐based IMRT, but most can deliver a maximum conformal field of 40×40 cm. It is possible and reasonable to deliver IMRT with compensators for fields this size with most conventional linear accelerators.

PACS numbers: 87.56.ng, 87.56.N, 87.55.D, 87.55.dk

Extrapleural pneumonectomy versus pleurectomy/decortication in the surgical management of malignant pleural mesothelioma: results in 663 patients

OBJECTIVE

The optimal procedure for resection of malignant pleural mesothelioma is controversial, partly because previous analyses include small numbers of patients. We performed a multi-institutional study to increase statistical power to detect significant differences in outcome between extrapleural pneumonectomy and pleurectomy/decortication.

METHODS

Patients with malignant pleural mesothelioma who underwent extrapleural pneumonectomy or pleurectomy/decortication at 3 institutions were identified. Survival and prognostic factors were analyzed by the Kaplan-Meier method, log-rank test, and Cox proportional hazards analysis.

RESULTS

From 1990 to 2006, 663 consecutive patients (538 men and 125 women) underwent resection. The median age was 63 years (range, 26-93 years). The operative mortality was 7% for extrapleural pneumonectomy (n = 27/385) and 4% for pleurectomy/decortication (n = 13/278). Significant survival differences were seen for American Joint Committee on Cancer stages 1 to 4 (P < .001), epithelioid versus non-epithelioid histology (P < .001), extrapleural pneumonectomy versus pleurectomy/decortication (P < .001), multimodality therapy versus surgery alone (P < .001), and gender (P < .001). Multivariate analysis demonstrated a hazard rate of 1.4 for extrapleural pneumonectomy (P < .001) controlling for stage, histology, gender, and multimodality therapy.

CONCLUSION

Patients who underwent pleurectomy/decortication had a better survival than those who underwent extrapleural pneumonectomy; however, the reasons are multifactorial and subject to selection bias. At present, the choice of resection should be tailored to the extent of disease, patient comorbidities, and type of multimodality therapy planned.

Biology and management of malignant pleural mesothelioma

Malignant mesothelioma is an aggressive tumour, with a poor prognosis and an increasing incidence as a result of widespread exposure to asbestos. The results of the treatments available are poor. Surgery and radiotherapy have a limited role in highly selected patients and systemic therapy is the only potential treatment option for the majority of patients. Despite some definite activity of the novel antifolates such as pemetrexed and raltitrexed, the results, even in combination with platinating agents, are still modest, with a median survival of approximately one year. The better understanding of the biology of mesothelioma makes the assessment of a number of targeted agents particularly interesting. Unfortunately, the targeted agents imatinib, gefitinib, erlotinib and thalidomide have been shown to be ineffective in unselected patients. Studies with anti-angiogenesis agents are ongoing. An improvement of the knowledge of major molecular pathways involved in malignant mesothelioma is needed in order to define proper targets for the systemic treatment of this disease.

Management of Malignant Pleural Mesothelioma

Malignant mesothelioma is increasing in incidence globally and has no known cure. Its unique clinical feature of local infiltration along tissue planes makes it a difficult neoplasm to manage. There have been few randomized controlled trials regarding treatment options, although these have increased in recent years, and results are eagerly awaited. This article summarizes important advances in the management of mesothelioma, especially diagnostic and therapeutic aspects.

A novel radiation therapy technique for malignant pleural mesothelioma combining electrons with intensity-modulated photons

BACKGROUND AND PURPOSE

To investigate the feasibility and potential benefits of combining electron and photon intensity modulated radiotherapy (IMRT) for patients with malignant pleural mesothelioma (MPM).

PATIENTS AND METHODS

The planning CT images of 11 MPM patients, six after extrapleural pneumonectomy (EPP) and five after pleurectomy/decortication (P/D), were used for this study. These cases were planned with photon IMRT alone and photon IMRT combined with electrons (IMRT+e). The latter approach incorporated the electron dose into the inverse planning optimization. The resulting doses to the planning target volume (PTV) and relevant critical structures were compared.

RESULTS

For all patients, the PTV was well covered and doses to critical structures were clinically acceptable for all patients with both techniques. However, IMRT+e exhibited a distinct advantage in reducing the doses to the liver, ipsilateral kidney, contralateral kidney, and heart (P=0.002, 0.003, 0.025, and 0.001, respectively).

CONCLUSIONS

This study showed that IMRT or IMRT+e is a viable treatment modality for MPM patients. Both plans can provide excellent target coverage and normal tissue sparing, but with the addition of electron beams, the critical structures can be further spared. Additional refining of the electron contribution is expected to further reduce radiation-induced morbidity.

["Therapeutic" pleural surgery]

Renewed interest in carcinological pleura surgery for the treatment of mesothelioma has resulted from an increased incidence of the tumor and also better control of postoperative mortality for an operation with a dramatic reputation. Techniques include pleurectomy, pleurodecrotication and wide pleuropneumectomy. To achive isolated resection of the parietal pleura or a combined resection of the parietal and visceral pleura with more or less wide resection of the diaphragm and pericardium. Indications depend on the tumor extension and the patient's status. Mortality, particularly for wide pleuropneumectomy is no well controlled by well-trained teams and is to the order of 5%. The rate of local recurrence is to the order of 10% and can warrant use of local treatments such as intrathoracic hyperthermic chemotherapy. Median survival for operated mesothelioma is 19 months with a 46% five-year survival for the tumors with the best prognosis. At the present time, radical surgical resection is the basis of local treatment for pleural mesothelioma.

Radiotherapy for mesothelioma

Three to four thousand cases of malignant pleural mesothelioma will occur in the United States this year. Single-modality therapy with radiation plays a role for palliation. Radiation can prevent tumor recurrence at drain/instrumentation sites and provide symptomatic relief of pain and other complaints. Combinations of surgery and radiation also have been attempted with curative intent. The best local control has been found--EPP followed by radiotherapy. Locoregional tumor recurrence can be dramatically reduced with combinations of extrapleural pneumonectomy and radiation therapy. Survival in aggressively treated early-stage patients is excellent. However, the preponderance of death from distant metastases makes the development of better systemic therapy essential. Better therapy also must be developed for patients who are not candidates for extrapleural pneumonectomy.

[Recent progress in treatment of malignant pleural mesothelioma]

Incidence of malignant pleural mesothelioma will rise until 2030-2040 because the elapsed time between exposure and diagnostic is up to several decades. Prognosis remains very poor with median survival less than one year and five-year survival not exceeding 5%. As compared to 1999, standart treatment adds chemotherapy with cisplatin and pemetrexed to local radiotherapy for prevention of local seeding after invasive diagnostic procedures. Despite various growth factors and their receptors are involved in malignant mesothelioma, first clinical trials of targeted therapies reported poor results. Multimodality therapy with extrapleural pneumonectomy and radiation therapy (+/-chemotherapy) can be of benefit in subgroups of patients but it cannot be recommended in a routine approach. As compared to bronchial carcinoma, inclusion of patients in clinical trials (using intensity-modulated radiation therapy) is the only way to somewhat improve results.

Hemithoracic radiation therapy after pleurectomy/decortication for malignant pleural mesothelioma

PURPOSE

To evaluate pleurectomy/decortication (P/D) and adjuvant radiotherapy (RT) in the treatment of malignant pleural mesothelioma (MPM).

METHODS AND MATERIALS

In a retrospective review, we included MPM patients treated with P/D and adjuvant RT at Memorial Sloan-Kettering Cancer Center from 1974 to 2003. When indicated, patients received intraoperative brachytherapy to residual tumor.

RESULTS

All 123 patients received external beam RT (median dose, 42.5 Gy; range, 7.2-67.8 Gy) to the ipsilateral hemithorax postoperatively. Fifty-four patients underwent brachytherapy (matched peripheral dose, 160 Gy). The median and 2-year overall survival for all patients was 13.5 months (range, 1-199 months) and 23%, respectively. One-year actuarial local control for all patients was 42%. Multivariate analysis for overall survival revealed radiation dose <40 Gy (p = 0.001), nonepithelioid histology (p = 0.002), left-sided disease (p = 0.01), and the use of an implant (p = 0.02) to be unfavorable. Two patients (1.6%) died from Grade 5 toxicity within 1 month of treatment.

CONCLUSIONS

Pleurectomy/decortication with adjuvant radiotherapy is not an effective treatment option for patients with MPM. Our results imply that residual disease cannot be eradicated with external RT with or without brachytherapy and that a more extensive surgery followed by external RT might be required to improve local control and overall survival.

A pilot trial of high-dose-rate intraoperative radiation therapy for malignant pleural mesothelioma

PURPOSE

To report results of a phase II trial of high-dose-rate intra-operative radiation therapy (HDR-IORT) for malignant pleural mesothelioma (MPM).

METHODS AND MATERIALS

Seven patients had extrapleural pneumonectomy with IORT (EPP/IORT) and 6 patients had pleurectomy/decortication with IORT (PD/IORT) between 1994 and 1996. IORT was delivered with 192Ir using a customized applicator with a remote afterloader. A median of 3 sites were treated to a median area of 143 cm2. A dose of 1500 cGy was prescribed at each site, with 1000 cGy delivered to the mediastinum. Postoperative external beam radiation therapy (EBRT) was given 3-5 weeks later. Median follow-up was 8 months (range, 1-84 months).

RESULTS

Five patients developed local failure. Two-year local control and survival rates were 35% and 23%, respectively. Mortality was 2/13 (15%), 1 from each surgical group. Serious complications requiring further intervention occurred in 3/6 (50%) of the EPP/IORT group and 1/5 (20%) of the PD/IORT group.

CONCLUSIONS

HDR-IORT after EPP for MPM is prohibitively toxic and has been abandoned, while its use with PD remains in question.

Pleurectomy and decortication for malignant mesothelioma

P/D in combination with other therapies remains an effective weapon in the thoracic surgeon's armamentarium for treating patients with MPM, particularly patients with limited lung function. A clear benefit has been demonstrated in terms of symptom relief. Further strategies aimed at eliminating residual disease in an effort to prevent locoregional recurrence and as potential curative therapies currently are being investigated.

Patterns of failure following surgical resection for malignant pleural mesothelioma

The optimum therapeutic strategy for patients with localized malignant mesothelioma continues to evolve. For patients who are eligible candidates, surgical resection plays an important role. An encouraging 45% 5-year survival rate has been reported for patients with early-stage disease who undergo EPP and have the favorable features of epithelial histology and the absence of mediastinal lymph node involvement. Most patients present with more advanced disease, however, and the optimum local and systemic treatment for these patients has not been defined. No randomized trials evaluating the various surgical or adjuvant therapeutic approaches have been performed. Evaluation of treatment efficacy based on observed patterns of failure may suffer from treatment selection biases. Most studies also do not separate out the failure patterns based on the initial stage (clinical or pathologic) of the disease. Consequently, it is difficult to discern the potential impact of a given adjuvant therapy. Given these limitations, however, some consistent observations from the available data can be made. For patients who undergo P/D, local recurrence (within the surgically operated hemithorax) is the most common form of recurrence. Efforts to decrease the chance of local recurrence after P/D have included the use of intrapleural and intravenous chemotherapy, brachytherapy, and external beam radiation therapy. None of these adjuvant treatment trials was randomized, and when compared with historical controls, none of the treatments used suggested a consistent outcome benefit. After P/D, the use of radiation is limited by the potential toxicity of the underlying organs, most importantly, the intact lung. Doses required to treat mesothelioma effectively are above the doses that would lead to damage to the lung parenchyma. Cisplatin and mitomycin have been used as agents have modest activity against mesothelioma. The doses of cisplatin used may not have been optimal, although they were based on prior pharmacokinetic studies. Alternative approaches for patients who undergo P/D, such as the use of escalating doses of heated intrapleural cisplatin (given with a renal protecting agent, sodium thiosulfate, which provides the opportunity to deliver higher doses of chemotherapy), are being pursued by Sugarbaker et al. The availability of more active systemic chemotherapy agents or other intrapleural agents also may offer better therapeutic options for patients who undergo P/D. Recently, Vogelzang et al presented the findings of a large randomized study that compared cisplatin/premetrexed to cisplatin and demonstrated an improvement in response rate (41% for cisplatin/pemetrexed versus 19% for cisplatin) and median survival (12.1 versus 9.3 months, respectively; P = 0.020). Other chemotherapy regimens with encouraging activity in mesothelioma include the combination of cisplatin and gemcitabine, with response rates ranging from 16% to 48%. From a review of available data, patients with mesothelioma who have undergone P/D (with or without intrapleural chemotherapy) who are evaluated at the Dana Farber Cancer Institute and Brigham and Women's Hospital are offered therapy with systemic chemotherapy alone. After P/D, radiation is used only for palliative treatment. Patients who have undergone P/D are also appropriate candidates to receive chemotherapy or other novel therapeutic strategies being evaluated in clinical trials. For patients who have undergone EPP, the pattern of recurrence is predominantly a combination of local and distant failure (Table 1). The local recurrence rates, however, seem to be lower than rates seen after P/D. This observation may represent a shift of the natural history of the disease. Metastatic mesothelioma is often seen late in the course of the disease, but it may become the dominant source of disease after aggressive local surgical management. Many studies define abdominal recurrence as a site of distant recurrence, although this may represent transdiaphragmatic extension of the pleural mesothelioma. Advances in local therapy also may decrease the rate of abdominal recurrences. True distant recurrences (bone, central nervous system, contralateral hemithorax) remain less common. The lowest rate of local recurrence (13%), with a 4% local-only recurrence rate, was seen in the study by Rusch et al, who used 54 Gy hemithorax radiation as adjuvant therapy. This is the lowest rate of local recurrence after an EPP that has been reported. Baldini et al reported a 50% local recurrence rate, with a 13% local-only rate, after trimodality therapy. One possibility for the differences between these two reports is the lower dose of radiation (30.6 Gy) used in the latter study. In the study by Rusch et al, distant failures predominate, and the patients are appropriate candidates for systemic chemotherapy, which could be administered either as neoadjuvant or adjuvant therapy. Kestenholz et al currently are performing a phase II clinical trial of neoadjuvant cisplatin and gemcitabine administered for three cycles followed by EPP and adjuvant radiation therapy. A similar approach also is being pursued in an ongoing clinical trial using neoadjuvant cisplatin/pemetrexed for four cycles before EPP followed by 54 Gy of adjuvant hemithorax radiation. Alternatively, patients who have undergone EPP could be treated with adjuvant chemotherapy in addition to adjuvant radiation therapy. Currently, patients evaluated at the Dana Farber Cancer Institute and Brigham and Women's Hospital who have undergone EPP are offered adjuvant chemotherapy followed by hemithorax radiation to 54 Gy in an effort to maximize local and distant control rates. Further clinical studies are needed for all patients with mesothelioma to define the optimum surgery and duration and types of adjuvant therapy. The appropriate multimodality approaches most likely will differ based on disease stage, histology, and patient performance status. intrapleural chemotheraphy treatments. These two For Patients who have undergone EPP, the pattern

External beam radiation therapy for the treatment of pleural mesothelioma

Technical challenges in the treatment of pleural mesothelioma with radiotherapy remain. When there is limited or no resection of disease, delivery of high-dose RT to the entire hemithorax in the setting of an intact lung has not been shown to be associated with any survival benefit, and the toxicity is clearly significant. Conversely, the use of palliative RT delivered to limited fields (less than hemithorax) can provide pain relief in 50% to 70% of cases. After pleurectomy and decortication, delivery of a tumoricidal dose of radiation to potential microscopic mesothelioma is similarly problematic. Details of various sophisticated radiation techniques, such as photon and electron matching, intraoperative RT, and the use of multiple small treatment beams using IMRT, have been published, and the former two techniques have been used. Although these approaches are innovative and creative, they have significant limitations in terms of the total dose that can be delivered, dose homogeneity, and the ability to cover fully all the areas at risk (e.g., fissures). Finally, implementation of RT after EPP permits delivery of higher doses than in the post-pleurectomy setting using treatment techniques such as photon/electron matching and IMRT. The dosimetry remains limited by the surrounding normal structures (heart and liver, particularly). Studies have shown that it is feasible to deliver nominal doses of 50 to 54 Gy after EPP, and local control rates have improved . Although the target volumes may not be covered fully by these doses, it is a significant improvement over lower dose treatment plans. In the future, it is reasonable to continue to pursue aggressive surgical resection with EPP and further refine these complex radiotherapy techniques. Treatment with novel agents, such as alimta, in the neoadjuvant setting also may further enhance local and systemic control of pleural mesothelioma.

Chemotherapy for malignant pleural mesothelioma: past results and recent developments

This review summarises results of previously conducted clinical trials and subsequently presents data arising from all phase II-III studies on chemotherapy for malignant pleural mesothelioma (MPM) published since the last relevant overview. While response rates exceeding 30% have barely been achieved with established cytotoxic drugs in MPM therapy, novel chemotherapeutic agents and their combinations appear somewhat more promising. This applies especially to the antimetabolites, and in particular to pemetrexed which produced response rates of up to 45% in combination with platinum compounds. Raltitrexed combined with oxaliplatin has also been shown to be effective, and gemcitabine--applied as a single agent or in combination with cisplatin--as well as vinorelbine appear to improve quality of life in patients presenting with MPM. Data can now be more precisely analysed by increasingly implemented randomised studies, applying a standardised staging system, and distinguishing prognostic groups. While chemotherapy for MPM remains a challenging task, important steps have clearly been made in the past years to combat this aggressive disease. Publication of results from a phase III trial of pemetrexed with cisplatin in a peer reviewed journal may soon establish a standard of care.

Promising early local control of malignant pleural mesothelioma following postoperative intensity modulated radiotherapy (IMRT) to the chest

PURPOSE

Malignant pleural mesothelioma often recurs locally in spite of aggressive resection by extrapleural pneumonectomy and conventional radiotherapy. This may be due to failure to recognize the extent of clinical target volume (CTV) or suboptimal dose delivery to a target that abuts the heart, esophagus, liver, lung, kidney, and spinal cord. We report how these geometric/dosimetric constraints were overcome by exploiting intensity-modulated radiotherapy in the first cohort patient.

MATERIALS AND METHODS

Twenty-eight patients who had undergone extrapleural pneumonectomy were treated with intensity-modulated radiotherapy. The CTV included the surgically violated inner chest wall, insertion of diaphragm, pleural reflections, and deep margin of the incision. CTV delineation was facilitated by intraoperative radio-opaque marking. Motion was assessed. CTV doses were 45-50 Gy with boosts taken to 60 Gy.

RESULTS

Despite the large, irregular CTV (median, 4151 cc; range, 2667-7286 cc), an average of 97% of the CTV was covered to the target dose (range, 92%-100%). Respiratory motion was minimal because of immobility of the prosthetic diaphragm. Normal tissue dose constraints were met. The commonest effects were nausea/vomiting (89%) and dyspnea (80%). Esophagitis was absent (59% of patients) or mild (34% grade 1/2). At median follow-up of 9 months (range, 5-27 months), local control within the contoured target was 100%. One-year survival, disease-specific survival, and disease-free survival are 65%, 91%, and 88%, respectively.

CONCLUSIONS

Intensity-modulated radiotherapy after extrapleural pneumonectomy is tolerable and seems effective, at least at this early point. As local control improves, systemic metastases become more common, and it may be appropriate to add novel agents to further improve the therapeutic ratio.

Intensity-modulated radiation therapy: a novel approach to the management of malignant pleural mesothelioma

PURPOSE

Malignant pleural mesothelioma (MPM) causes symptoms and death mainly due to local progression, even after combined modality treatment. Poor local control after conventional radiotherapy may be due to the low dose of radiation that has been administered or to restriction of the target volume to avoid critical organs. Intensity-modulated radiation therapy (IMRT) has the potential to overcome these geometric/dosimetric constraints.

METHODS AND MATERIALS

Seven patients with MPM who had an extrapleural pneumonectomy (EPP) were treated with adjuvant IMRT. The clinical target volume (CTV) included the surgically violated area inside the chest wall with particular attention to the insertion of the diaphragm, pleural reflections, and the deep margin of the thoracotomy incision. Treatment was delivered by intensity-modulated 6-MV photon beams using dynamic multileaf collimation.

RESULTS

The CTV ranged from 2667 to 7286 mL. The average CTV covered to 50 Gy was 94% (range, 92% to 98%). Respiratory motion was minimal. The average volume of the boost areas covered by 60 Gy was 92% (range, 82% to 99%). Dose-volume constraints for normal tissue were met in almost all cases. Acute toxicity was mild to moderate. The most severe side effects were anorexia, nausea or vomiting, and dyspnea. Esophagitis was absent or mild. After a minimum of 13 months follow-up care there were no cases of disease recurrence within the ipsilateral hemithorax.

CONCLUSION

Treatment of the extensive operative area after an EPP is feasible using IMRT. Input from the radiologist and from the surgeon in the planning process facilitates definition of the high dose volumes. In light of patients' tolerance to post-EPP IMRT, it may be feasible to incorporate systemic therapy, including novel biologic therapies into the treatment regimen.

Surgical treatment of malignant pleural mesothelioma: a review

Despite many years of clinical research, there is still no effective therapy for malignant pleural mesothelioma (MPM). Untreated, the prognosis is poor, with a median survival of < 1 year. Single-agent or combination chemotherapy as well as radiotherapy have not shown persistent improvements in response or survival. In general, MPM is a disease confined to the pleural cavity for a long time before metastasizing. Therefore, focus on local treatment seems rational. Surgical resection has been considered the mainstay of treatment by some. However, surgery alone results in high recurrence rates, and the survival benefit remains questionable. In recent years, the emphasis has been on surgery combined with adjuvant therapies. In this article, the present state of surgical management of MPM will be reviewed.

Chemotherapy for malignant pleural mesothelioma: past results and recent developments

This review summarises the results of previously conducted clinical trials, and subsequently presents data arising from all phase II-III studies on chemotherapy of malignant pleural mesothelioma (MPM) published since the last relevant overview. While response rates exceeding 30% have barely been achieved with established cytotoxic drugs in MPM therapy, novel chemotherapeutic agents and their combinations appear more promising. This applies especially to the antimetabolites, and in particular to pemetrexed that produced response rates of up to 45% in combination with platinum compounds. Raltitrexed combined with oxaliplatin has also been shown to be effective, and gemcitabine-applied as a single agent or in combination with cisplatin-as well as vinorelbine appear to improve the quality of life in patients presenting with MPM. Data can now be more precisely analysed by increasingly implemented randomised studies, applying a standardised staging system, and distinguishing prognostic groups. While chemotherapy for MPM remains a challenging task, important steps have clearly been made in the past years to combat this aggressive disease. The publication of pemetrexed with cisplatin phase III results in a peer-reviewed journal may soon establish a standard of care.

Radical pleurectomy/decortication and intraoperative radiotherapy followed by conformal radiation with or without chemotherapy for malignant pleural mesothelioma

OBJECTIVES

We performed a retrospective review of the efficacy and morbidity of radical pleurectomy/decortication and intraoperative radiotherapy followed by external beam radiation therapy with or without chemotherapy for diffuse malignant pleural mesothelioma.

METHODS

A total of 32 patients with diffuse malignant pleural mesothelioma were initially evaluated between January 1995 and September 2000. Three patients were excluded from analysis because of unresectable disease. Two patients died postoperatively, and one patient had recurrent disease previously treated at an outside institution. Of the remaining 26 patients included in the analysis, 24 received intraoperative radiotherapy. External beam radiation therapy was generally started 1 to 2 months after resection and delivered by means of 3-dimensional conformal radiation therapy or with inverse treatment planning intensity-modulated radiation therapy. When given, chemotherapy consisted of 2 to 3 cycles of cyclophosphamide, doxorubicin (Adriamycin), and cisplatin initiated 1 to 2 months after completion of radiation.

RESULTS

At the time of data analysis, 5 of 26 patients were alive. The median follow-up was 9.7 months (range, 2-67.6 months). The median overall survival and progression-free interval from the time of the operation were 18.1 and 12.2 months, respectively. The Kaplan-Meier estimates of overall survival and freedom from progression at 1 year were 64% and 50%, respectively. The site of failure was mostly locoregional. However, there were 4 abdominal failures and 1 contralateral lung failure.

CONCLUSIONS

Radical pleurectomy/decortication with aggressive radiotherapy with or without chemotherapy might offer an alternative treatment option to those who cannot tolerate extrapleural pneumonectomy.

Malignant mesothelioma: options for management

In the past, there has been a tendency to think of diffuse malignant pleural mesothelioma as one disease in therapeutic terms, regardless of histological type and tumor stage. This does not happen with other tumors, yet it is equally illogical and inappropriate in mesothelioma. As with other tumors, early diagnosis-while the disease is still in stage I, or even at an in situ stage-must be the goal so that therapy can be maximized, particularly if immunotherapy or gene therapy is to be used. Patients with pure epithelial mesothelioma have a better prognosis and respond better to trimodality therapy. Stage I patients who meet fitness criteria should be offered the option of radical surgery in combination with chemotherapy and radiotherapy. Further research is required to determine the optimum neoadjuvant and adjuvant modalities, particularly the timing of individual drugs, use of hyperthermia, and route of administration. The place of immunotherapy and gene therapy as adjunctive treatments also remains to be defined. For example, it may be possible to reduce tumor bulk and perhaps downstage the disease with immunotherapy before radical surgery, if treatment is started early enough. Gene therapy may have a role either preoperatively or in destroying the microscopic disease that remains after radical surgery. These and other combinations of treatment need to be tested in well-designed clinical trials, probably on a multicenter basis (to enroll a sufficient number of patients). Finding the means to improve treatment for sarcomatous and mixed histology mesothelioma remains a challenge. At present, radical surgery does not seem worthwhile for these patients when combined with currently employed chemotherapy and radiotherapy; however, chemotherapy combinations used for treating other sarcomas need to be evaluated as adjunctive therapy before radical surgery is abandoned altogether as a mode of treatment. A collaborative approach involving thoracic surgeons, basic scientists and oncologists, and physicians with experience in treating mesothelioma is essential. Despite its increasing frequency, mesothelioma is still a relatively rare tumor, so treatment should be concentrated in relatively few supraregional centers to maximize expertise and allow innovative treatment combinations to be implemented with the greatest chance of success. Evaluation of new therapeutic approaches will be achieved more rapidly if these supraregional centers collaborate in multicenter trials. The nihilistic approach of simply waiting until the mesothelioma epidemic eventually begins to decline spontaneously in 20 or 30 years is untenable in view of the hundreds of thousands of deaths that will result if no effective treatment is found.

Phase II trial of a single weekly intravenous dose of ranpirnase in patients with unresectable malignant mesothelioma

PURPOSE

A multicenter phase II trial of ranpirnase (Onconase; Alfacell Corp, Bloomfield, NJ) as a single agent was conducted to further assess the safety and clinical efficacy of this novel antitumor ribonuclease. Patients with unresectable and histologically confirmed malignant mesothelioma (MM) were eligible.

PATIENTS AND METHODS

One hundred five patients with Eastern Cooperative Oncology Group performance status 0 to 2 were enrolled onto the study. Thirty-seven percent of patients had not responded to prior chemotherapy. The primary end point of the study was survival. Tumor responses and time to progression were also assessed. The Cancer and Leukemia Group B (CALGB) prognostic group criteria were used to define a treatment target group (TTG). Both the intent-to-treat (ITT) and the TTG populations were analyzed for survival.

RESULTS

Median survival times of 6 months for the ITT and 8.3 months for the TTG populations were observed. The 1- and 2-year survival rates were 34.3% and 21.6% for ITT, respectively, and 42% and 26.8% for TTG, respectively. Among the 81 patients assessable for tumor response, four had partial responses, two had minor regressions, and thirty-five experienced stabilization of previously progressive disease. Patients with responses and stable disease demonstrated markedly prolonged survival. Ranpirnase was well tolerated in the majority of patients, and there were no drug-related deaths.

CONCLUSION

Ranpirnase demonstrated activity and a tolerable toxicity profile in patients with unresectable MM. The prognostic value of the CALGB groups was confirmed.

A phase II trial of surgical resection and adjuvant high-dose hemithoracic radiation for malignant pleural mesothelioma

BACKGROUND

Surgical resection of malignant pleural mesothelioma is reported to have up to an 80% rate of local recurrence. We performed a phase II trial of high-dose hemithoracic radiation after complete resection to determine feasibility and to estimate rates of local recurrence and survival.

METHODS

Patients were eligible if they had a resectable tumor, as determined by computed tomographic scanning, and adequate cardiopulmonary function for extrapleural pneumonectomy or pleurectomy/decortication. After complete resection, patients received hemithoracic radiation (54 Gy) and then were followed up with serial computed tomographic scanning.

RESULTS

From 1995 to 1998, 88 patients (73 men and 15 women; median age, 62.5 years) were entered into the study. The operations performed included 62 extrapleural pneumonectomies (70%) and 5 pleurectomies/decortications; procedures for exploration only were performed in 21 patients. Seven (7.9%) patients died postoperatively. Adjuvant radiation administered to 57 patients (54 undergoing extrapleural pneumonectomy and 3 undergoing pleurectomy/decortication) at a median dose of 54 Gy was well tolerated (grade 0-2 fatigue, esophagitis), except for one late esophageal fistula. The median survival was 33.8 months for stage I and II tumors but only 10 months for stage III and IV tumors (P =.04). For the patients undergoing extrapleural pneumonectomy, the sites of recurrence were locoregional in 2, locoregional and distant in 5, and distant only in 30.

CONCLUSION

Hemithoracic radiation after complete surgical resection at a dose not previously reported is feasible. This approach dramatically reduces local recurrence and is associated with prolonged survival for early-stage tumors. Stage III disease has a high risk of early distant relapse and should be considered for trials of systemic therapy added to this regimen of resection and radiation.

Management of malignant pleural mesothelioma: a critical review

Malignant mesothelioma remains a uniformly fatal disease and best supportive care continues to be the standard treatment. Neither chemotherapy nor surgery has been shown to prolong survival. Radiotherapy is not curative but is useful for prophylaxis against needle-track metastases and for symptom palliation. Combinations of therapies have been tried but most studies were uncontrolled and selection bias makes the results impossible to interpret. The combination of extrapleural pneumonectomy, chemotherapy, and radiotherapy attracted much interest, but the subsequent results were disappointing in a highly selected group of patients. Randomized controlled trials are desperately needed to provide definitive information on experimental treatments. It is also important to develop better measures of disease response and to assess quality of life issues in clinical trials. If patients are to receive therapies other than palliation, they should only do so in the setting of randomized controlled trials under approved protocols.

Advances in the treatment of malignant pleural mesothelioma

Malignant pleural mesothelioma is a neoplasm that is commonly fatal and for which there are no widely accepted curative approaches. Mesothelioma is unresponsive to most chemotherapy and radiotherapy regimens, and it typically recurs even after the most aggressive attempts at surgical resection. Multimodality approaches have been of some benefit in prolonging survival of very highly selected subgroups of patients, but they have had a relatively small impact on the majority of the patients diagnosed with this disease. As the incidence of pleural mesothelioma peaks in the United States and Europe over the next 10 to 20 years, new therapeutic measures will be necessary. This review will discuss the roles of chemotherapy, radiotherapy, surgery, and combined modality approaches in the treatment of pleural mesothelioma, as well as scientific advances made in the past decade that have led to the development of experimental techniques, such as photodynamic therapy, immunotherapy, and gene therapy, that are currently undergoing human clinical trials. These promising new avenues may modify the therapeutic nihilism that is rampant among clinicians dealing with mesothelioma.

Phase III randomized trial of surgery with or without intraoperative photodynamic therapy and postoperative immunochemotherapy for malignant pleural mesothelioma

BACKGROUND

Patients with malignant pleural mesothelioma (MPM) usually die of progressive local disease. This report describes the results of a Phase III trial comparing maximum debulking surgery and postoperative cisplatin, interferon alpha-2b, and tamoxifen (CIT) immunochemotherapy with and without intraoperative photodynamic therapy (PDT) to determine (1) whether such a multimodal approach can be performed with minimum morbidity and mortality in malignant pleural mesothelioma (MPM), and (2) whether first-generation (i.e., 630-nm laser light, Photofrin II) intrapleural PDT impacts on local recurrence of survival.

METHODS

From July 1993 to June 1996, 63 patients with localized MPM were randomized to either PDT or no PDT. The tumors of 15 patients could not be debulked to 5 mm. Patients assigned to PDT (n = 25) and no PDT (n = 23) were similar with respect to age, sex, tumor volume, and histology.

RESULTS

The type of resection (11 pleurectomies and 14 pneumonectomies vs. 12 pleurectomies and 11 pneumonectomies), length postoperative stay, and ICU time were comparable (PDT vs. no PDT). There was one operative death (hemorrhage), and each group had two bronchopleural fistulas. Postoperative staging divided patients into the following categories: stage I: PDT, 2, no PDT, 2; stage II: PDT, 2, no PDT, 2; stage III, PDT, 21; no PDT, 17; stage IV, PDT, 0; no PDT, 2. Comparable numbers of CIT cycles were delivered. Median survival for the 15 non-debulked patients was 7.2 months, compared to 14 months for the 48 patients on protocol. There were no differences in median survival (14.4 vs. 14.1 months) or median progression-free time (8.5 vs. 7.7 months), and sites of first recurrence were similar.

CONCLUSIONS

Aggressive multimodal therapy can be delivered for patients with higher stage MPM. First-generation PDT does not prolong survival or increase local control for MPM.

Brachytherapy for non-small cell lung cancer and selected neoplasms of the chest

This article reviews the indications, techniques, and results of brachytherapy in the treatment of non-small cell lung cancer (NSCLC) and selected chest neoplasms. Various isotopes and techniques are used to place radioactive sources directly into a tumor, tumor bed, or the chest. Brachytherapy techniques can be tailored to the clinical situation and can be in the form of permanent interstitial volume or planar implants (radioactive sources permanently imbedded into the tumor or tumor bed) or in the form of temporary interstitial or endoluminal implants (where radioactive sources irradiate a tumor bed over a certain length of time and then are removed). These treatments can be delivered over a short interval (high-dose rate [HDR]) or over a more protracted time (low-dose rate). HDR treatments can be used intraoperatively to deliver a large dose of radiation to a determined target area with selective sparing of surrounding normal structures. Different methods of delivering HDR intraoperative radiation are under investigation. Most reports on brachytherapy for chest malignancies are retrospective and come from a few single institutions. Most of the published data relate to the treatment of NSCLC, but other intrathoracic malignancies, such as malignant pleural mesothelioma and malignant thymoma, have been treated with brachytherapy. To our knowledge, no major randomized trials accurately assess or confirm these retrospective studies yet, complicating the interpretation of these results. Nevertheless, brachytherapy is of value in selected situations and offers the clinician and the patient an innovative method of delivering conformal high-dose radiation to a defined target with preferential sparing of normal surrounding structures. With continued innovations in the development of radioactive isotopes, computerized treatment planning and targeting, and source delivery, brachytherapy should continue to offer an attractive alternative and complement to conventional treatment approaches, and may offer patients improved local control and survival.

Patterns of failure after trimodality therapy for malignant pleural mesothelioma

BACKGROUND

Malignant pleural mesothelioma is uncommon, and presently, no standard treatment of this disease exists. The objective of our analysis was to study the patterns of failure for malignant pleural mesothelioma after trimodality treatment consisting of extrapleural pneumonectomy, chemotherapy, and radiation therapy.

METHODS

Between 1987 and 1993, 49 patients with malignant pleural mesothelioma underwent extrapleural pneumonectomy. There were two perioperative deaths, and 1 patient died 5 weeks after extrapleural pneumonectomy. Thirty-five of the surviving patients received adjuvant chemotherapy (32/35 received cyclophosphamide, doxorubicin, and cisplatin) followed by hemithorax radiation therapy. Ten patients received chemotherapy but no radiation therapy, and 1 patient received no adjuvant therapy. Median follow-up time for the 23 living patients from the date of operation was 18 months.

RESULTS

Of the 46 evaluable patients, 25 had recurrence (54%), with a median time to first failure of 19 months (range, 5 to 51 months). The sites of first recurrence were local in 35% of patients, abdominal in 26%, the contralateral thorax in 17%, and other distant sites in 8%. (Some patients had recurrence in multiple sites simultaneously.)

CONCLUSIONS

The most common site of failure after trimodality therapy was the ipsilateral hemithorax. Isolated distant failures were uncommon. Future strategies should investigate methods of enhancing local tumor control.