Lung metastases affect a significant part of the ASPS patients at some point of their life, they can be very multiple and wide spread. It is very important to detect them early for an optimal management so all ASPS patients have to be monitored for the possible lung metastases development. For ASPS patients the use of aggressive surgery, appropriate diagnostic imaging, and long-term surveillance for metastases are critical to achieve long-term survival (Kayton et al 2006). If recurrent lung metastases appear, repeated surgeries to remove these tumors are recommended as their removal has been shown to improve survival (Liebl et al 2007).

Generally there are two ways to remove or destroy lung metastases:

1. Resection - by a standard open lung surgery (by a thoracotomy or sternotomy approach) or VATS (video-assisted thoracic surgery). It is a challenging task and not always technically feasible, each case is different due to the size, number and location of the metastases and only thoracic surgeon will be able to say based on a CT scan if a given case is resectable. To be eligible for a resection lungs have to be the only active metastatic organ with the primary tumor resected and other metastases successfully treated before.

2. Ablation - a local treatment done percutaneously by an interventional radiologist using one of the less invasive methods (cryoablation, radiofrequency ablation or LITT) or by non-invasive methods (stereotactic radiosurgery (SRS) or tomotherapy).Previously, we reviewed the use of stereotactic radiosurgery (SRS) here.

Now, we will discuss laser assisted surgery for the removal of multiple lung metastases in a surgical procedure. Open lung surgery (by a thoracotomy or sternotomy approach) is a gold standard if the goal is to resect all lung metastases. Lung metastases smaller than 2 mm often cannot be seen on the CT scan. Open surgery allows the surgeon to visually inspect the lungs, as well as palpate (explore by touch) the lung tissue. An experienced surgeon can find a metastasis as small as 0.5-1 mm by this method. Traditionally, lung metastases are removed by ”wedge” or “lobe resection”. In that type of surgery, tumor (or tumors) are removed from the lung by stapling and clamping devices. Due to the geometric straight lines and angles of the stapler, the removal of lung metastases by this method results in a considerable loss of healthy lung tissue. Loss of a large amount of lung tissue can ultimately lead to a decrease in lung function. Another downside of this technique is the limitation of the location - there has to be an open edge to use a stapler. This means that tissue is removed in the shape of a pizza slice. If the metastases are centrally located or deep seated they are not accessible for this surgical tool. Hence, metastatic disease to the lungs is considered to be unresectable unless a whole lobe or a lung is being removed. ASPS is often a very disseminated disease, with all of the lobes affected. In this case, resection is not feasible using the conventional stapler assisted method. In some cases, complete resection can still be done by a new technique - laser assisted resection. To use this technique, the surgeon employs a special medical laser. The advantages of this tool are a high degree of precision and an ability to resect deep seated and centrally located metastases without critical loss of lung parenchyma. Using the laser, the surgeon can follow along the contour of the metastasis and remove it, thereby sparing much of the healthy lung tissue and its function. This may be crucial for patients with multiple metastases. It provides the patient with a better quality of life and allows repeated surgery, if needed.

Dr. Axel Rolle, from the Department of Thoracic and Vascular Surgery, Coswig (Dresden), Germany has been working on this laser technique since 1988, developing therapeutic laser technology for the resection of lung tissue (parenchyma). Lung parenchyma contains 80% water, and is of very low density (lots of air chambers). Therefore, in order for the laser to work in this type of tissue, it must have excellent cutting properties, and be able to control bleeding easily (coagulation). The first lasers in use were based on 1064nm wavelength laser. Dr. Rolle has developed and is using since the late 90-ties a longer wavelength laser of 1318nm, which is emitted from Nd:YAG. He found that this laser has both better precision when cutting, preserving the tissue around the metastasis, and improved bleeding control. Dr. Rolle has published these findings demonstrating the clinical benefit of this technique (Rolle et al 2006 (1)). This procedure is an unique opportunity to remove maximal tumor load from the lungs in a parenchyma-saving and lobe-sparing approach.

In a recent scientific publication, Dr. Rolle reported the results of a study, which aimed to define the role of his new 1318-nm Nd:YAG laser, in order to preserve lung tissue for patients with multiple lung metastases (Rolle et al 2006 (2)). During the period of that study: January 1996 to December 2003, a total of 328 cancer patients were treated with the new 1318 nm Nd:YAG laser system. A total of 3267 lung nodules were resected by the laser (an average of 10 tumors per patient (range 2-124). Despite the unusually high number of the resected metastases due to the most difficult cases being referred for his surgery the lobectomy rate was only 7 %.
Dr. Rolle concludes -

“This new 1318-nm Nd:YAG laser facilitates complete resection of multiple bilateral centrally located metastases and thus is lobe sparing. Outcomes are better when metastases are removed completely from the lung for long-term survival than those patients who had incomplete resection”.

Dr. Rolle contact information at the Center for Pneumology and Thoracic and Vascular Surgery, Academic Teaching Hospital of Dresden University:

Dr. Rolle
Fachkrankenhaus Coswig GmbH
Neucoswigerstr. 21
01640 Coswig
Germany

Phone: 0049 (0)3523 - 65 102
Fax: 0049 (0)3523 - 65 103
E-mail: prof.rolle@fachkrankenhaus-coswig.de

Dr. Rolle’s website: http://www.lungenmetastasen.info/Index_englisch.htm

More information about laser surgery:

1. Dr. Rolle performed laser assisted resections on at least two ASPS patients with very multiple lung metastases. You can read one first hand experience at this link.

2. Laser Lung surgery website created by a sarcoma patient: http://www.geocities.com/laserlungsurgery/

3. Read more about laser resection at the National Cancer Institute website: http://www.cancer.gov/cancertopics/factsheet/Therapy/lasers
__________________________

Yosef Landesman, Ph.D. (in cooperation with Olga Tkatcheva and Ivan Goroun)
President & Cancer Research Director
Cure Alveolar Soft Part Sarcoma International (iCureASPS)
e-mail: landesmany@yahoo.com

Stereotactic Radiosurgery (SRS) is a medical procedure, which is non-invasive surgery to destroy tumors. High dose of ionizing radiation is precisely delivered into a specific area of an organ to kill tumor cells. The beam of radiation is the surgical knife in radiosurgery. The most common forms of ionizing radiation are: proton beams, X-rays and photons.

Unlike conventional surgery that removes tumors by bulk dissection, SRS only distorts the DNA of the tumor cells. Those cells then lose their ability to divide. Tumor shrinkage can be seen often over several months.

Currently there are three basic forms of stereotactic radiosurgery: Cobalt-60 (photon), Linear accelerator (linac) and Particle beam (proton). Each one is different from the other in both the equipment used and the radiation emitted. One type may be more effective than the other depending on the location of the tumor.

1. Cobalt-60 (photon) - also called a Gamma Knife® is an extremely accurate instrument used to treat brain tumors. The Gamma Knife® allows noninvasive brain surgery, sparing tissues adjacent to the target. The beams of gamma radiation are programmed to target the tumor at the point where they intersect. In a single treatment session, 201 beams of gamma radiation focus precisely on the tumor. Over time, most lesions slowly shrink in size and dissolve. The exposure is brief and only the tissue being treated receives a significant radiation dose, while the surrounding tissue remains unharmed. The Gamma Knife® technology is used for tumors which are small, less than 3.5 cm, or in patients who have limited symptoms from the tumor. When Gamma Knife® cannot be utilized or is not available to the patient, radiosurgery with linear accelerator technology can usually be utilized.

Click here to read more about Gamma Knife® at the university of Pittsburg, at the Johns Hopkins, at the University of Virginia.

2. Linear accelerator (linac)
Linac is short for the term “linear accelerator”. The Linear accelerator instruments produce high-energy X-ray radiation. Conventional X-rays are a form of electromagnetic radiation with short wavelength, without charge or mass. The most improved linac technology is based on Intensity - Modulated Radiation Therapy (IMRT). It takes into account the three-dimensional shape of the tumor. This is done through the use of a CT scanner that is incorporated into the IMRT. The CT scans identify the exact tumor location and its shape. The radiation beams in varying intensities are delivered to the tumor with increased accuracy, reducing the harmful effects of the X-rays on normal tissue.
This treatment is very beneficial for large tumor (up to 2.5 cm) in one-session, and tumors greater in size (over 3.5 cm) in several treatment sessions. When several treatments are required this is called fractionated stereotactic radiotherapy. Linear accelerator based machines can be used to treat tumors throughout the body, as well as in the head and neck.

The linac machines are made by multiple manufacturers with common brand names such as: X-Knife®, Axess®, Trilogy®, Novalis®, CyberKnife®, TomoTherapy® .

Read more about Cyberknife:
Cyberknife to treat tumors anywhere in the body
Cyberknife, frequently asked questions
Cyberknife at Stanford
Compare: Gamma Knife versus Cyberknife to treat brain tumors

3. Particle beam (proton) – Also known as Proton beam, is radiation of positively charged particles that impact the tumor cells by way of their mass. The side effects of the treatment with Proton beam are less than those that are caused by X-ray treatment. X-rays affect cells as they travel through the body in a straight line, delivering injury both at the surface of the body where they enter, and in tissues behind the cancer. Proton beams do not travel all the way through the body and can be used very accurately to kill cancer cells without the collateral damage seen with traditional radiation: Proton beams can be controlled to deposit the bulk of their energy at the EXACT tumor location. The Proton beam machines are very expensive and therefore exist only in six centers in the United States: M.D. Anderson in Houston; Loma Linda University Medical Center in California AND Proton treatment at Loma Linda; The Midwest Proton Radiotherapy Institute in Bloomington, Indiana; Massachusetts General Hospital, Boston; The University of Florida Proton Therapy Institute in Jacksonville; and the University of California, Davis Cancer Center in Sacramento.

Click here to Read more about Proton Beam

*This summary aims to introduce you into SRS. Please be aware that we mentioned only some of the centers, which practice SRS. While some centers treat cancer in only few organs, other centers may use the same technique to treat tumors in more locations.

__________________________

Yosef Landesman, Ph.D.
President & Cancer Research Director
Cure Alveolar Soft Part Sarcoma International (iCureASPS)
e-mail: landesmany@yahoo.com