Lung Mets Treatment Options
The most common area where ACC mets will develop is in the lungs, with the liver being the next most prevalent. The primary focus of this list of treatment options is to address lung mets, though all 3 of the basic modalities have been utilized for treating liver mets as well. When dealing with lung mets, these modalities are primarily used to treat specific, isolated tumors or a specific cluster of tumors in a region in one of the lungs. These are not commonly utilized to address multiple lung mets spread out over all the five lobes, which would require a systemic type treatment such as chemotherapy or a targeted drug treatment. At the present time there are no proven chemotherapy or targeted drug treatments that have shown themselves to be effective for any large numbers of ACC patients.
Patients can now view their own CT scans of their lungs by obtaining a copy of their scan on CD from their medical provider and running that CD on their PC. Generally the viewing software is on the CD and just takes some basic navigation learning to view. One of our members has provided a site where you can actually view a series of ACC patients lung met scans with explanations of growth, shrinkage and treatment results.
To view a series of CT scan images of ACC lung mets with explanation or to view the results of some treatments (e.g. SBRT, CyberKnife, Novalis TX, Afterloading, RFA, Brachytherapy)
The 3 Primary Modalities for Treating Lung Mets Include:
1) Surgery 2) Stereotactic Body Radiation Therapy 3) Interventional Radiology
1) Surgical Resection for Lungs
Thoracoscopic lung surgery/biopsy (VATS: video-assisted thoracic surgery)
Thoracoscopy is the insertion of an endoscope through a very small incision in the chest wall. An endescope is a small diameter tube with a viewing mirror or camera attachment. This procedure is used to directly visualize the pleura, lungs, and mediastinum, to obtain tissue for biopsy testing and staging, and for surgical dissection or resection of lung mets. Thoracoscopy is most commonly performed in a hospital so that general anesthesia can be used.
Removal of a relatively small, localized, wedge shaped area of the lung that includes the tumor with little or no affect on pulmonary structures or functioning after healing. This generally involves spreading or removing a section of ribs to allow adequate room for the surgery.
Segmental resection or Segmentectomy
A surgical procedure to remove part of an organ or gland. It is typically done to remove a tumor and some normal tissue around it to achieve clean margins. In lung cancer surgery, segmental resection refers to removing a larger section of a lobe of the lung than that done with a smaller wedge resection. A segmentectomy should be considered as one of the last surgical options due to the loss of valuable lung tissue and the related lung functioning. Commonly ACC metastases have a high tendency to appear in both lungs and to spread into more than one lobe. A less invasive treatment (RFA, Brachytherapy, Cryoablation, SBRT) should be considered to maintain as much healthy lung tissue as possible.
The removal an entire, complete lobe of the lung. The lungs are subdivided into sections referred to as "lobes". The right lung has three lobes (upper, middle and lower), while the left lung has two lobes (upper and lower). A lobectomy is an operation in which the surgeon completely removes one of the lobes and it's air supply. The suffix or term "ectomy", when attached to the name of a body part, generally means that body part or a part of the body part is being removed, such as in “appendectomy”. After a lobectomy, some compensatory non-pathologic emphysema occurs as the remaining lung tissue over-expands to fill in that portion of the thoracic space previously occupied by the resected tissue. A lobectomy should be one of the last surgical options chosen due to the loss of valuable lung tissue and the related lung functioning.
The removal of a complete left or right lung. The suffix or term "ectomy", when attached to the name of a body part, generally means that body part or a part of the body part is being removed, such as in “appendectomy”. This is obviously the most drastic measure in stopping the spread of cancer, yet is highly effective in dealing with a major infiltration of metastatic disease as long as the remaining lung is healthy enough to sustain adequate oxygen supply. Commonly ACC metastases have a high tendency to appear in both lungs and to spread into more than one lobe. A less invasive treatment (RFA, Brachytherapy, Cryoablation, SBRT) should be considered to maintain as much healthy lung tissue as possible.
Laser surgery for lung metastases (Laserpulmotomy) is another form of surgery (thoracotomy) but with a laser instead of a scalpel. One surgeon in Germany has removed approximately 150 growths from a single patient. The surgery is commonly done with a Yag-laser where the met is simply cut out with a small safety margin. Left and right lungs have to be 2 separate sessions. This method saves much more healthy lung tissue than Segmentectomy, Lobectomy and Pneumonectomy. But it is major surgery with a long recovery period and substantial pain because of the ribs being spread for the thoracotomy.
2) Stereotactic Body Radiation Therapy Manufacturer Systems
CyberKnife and CyberKnife VSI (Accuray)
A radiation delivery system utilizing a frame-less robotic system which is capable of delivering high doses of radiation to tumors with extreme accuracy without damaging healthy surrounding tissue.
Trilogy can deliver all forms of external-beam radiation therapy – from conventional radiation treatment and intensity modulated radiation therapy (IMRT) to the newest and most advanced techniques, such as image-guided radiotherapy (IGRT) and stereotactic body radiotherapy (SBRT). Trilogy’s built-in imaging system can pinpoint the size and location of a patient’s tumor moments before each treatment, and a “respiratory gating” component automatically synchronizes the radiation beam to the patient’s breathing.
Novalis TX (BrainLAB/Varian)
The Novalis shaped beam radiosurgery integrates state-of-art imaging and targeting software with a high energy shaped beam delivery system to obliterate tumors within the brain and elsewhere, without damaging the normal surrounding tissues. The idea behind Novalis is conceptually straightforward. It combines many precisely shaped beams, each directed toward the tumor, but each from a different direction. By doing this, it is possible to achieve a tumor-killing dose where the beams intersect, while keeping the dose from each individual beam below that which would cause any normal tissue complications.
Tomotherapy, literally “slice therapy,'' is the delivery of radiation therapy with intensity-modulated strips of radiation. The method employs a linear accelerator, or another radiation-emitting device, which would be mounted on a ring gantry like a CT scanner. The patient moves through the bore of the gantry simultaneously with gantry rotation. The intensity modulation is performed by temporally modulated multiple independent leaves that open and close across the slit opening.
Synergy S (Elekta) - Elekta Synergy® S
The Synergy S delivers high dose radiation rates with exceptionally fine control and precision. The system enhances avoidance of critical structures during beam delivery with its innovative 3D imaging technology. This technology allows beam adaptation for individual treatment sessions to achieve high precision and excellent target conformance. Digital controls maximize the accuracy of dose delivery without compromise. Elekta Synergy® S offers 1mu dose resolution, with stable dose/ mu calibration and the most accurate IMRT and VMAT delivery available.
The use of Omnibeam does not require doctors to surgically implant metal markers, but rather uses Real-time Image Guidance. The use of live imaging at each treatment session that is significantly more accurate, so Omnibeam can precisely target cancer cells. It uses low-dose 3-D cone-beam CT images for alignment, rather than 2-D X-ray images or high-dose CT scan images. Computer-controlled robotic equipment automatically and instantly corrects for external movement by the patient or internal movement of organs. It reduces the length and number of treatment sessions because the high-powered linear accelerator delivers the highest dose possible precisely at the target to quickly destroy cancer cells. Its accuracy has been proven in numerous studies (in real clinical settings, not labs) and published in peer-reviewed journals.
Primatom delivers fast, 3-D tumor localization prior to any treatment fraction, providing an opportunity to escalate dosage, reduce complications, and evaluate the therapeutic effectiveness of treatment. CT functionality in the treatment room provides diagnostic quality images with the patient in the actual treatment position, ensuring routine visualization of the tumor in order to check for anatomical movement. The CT scanner under the control of the therapy department can help to manage the scheduling and acquisition of patients’ CT image data for simulation, planning and treatment purposes.
Proton Therapy is a precise form of radiation treatment for cancer and other conditions. By minimizing damage to healthy tissue and surrounding organs, proton treatment is highly successful and results in fewer side effects. Proton beam “skips over” healthy tissue to deposit the radiation energy on the tumor with a high level of precision, thus minimizing damage to good tissue and minimizing side effects.
3) Interventional Radiology
Interventional Radiology Defined: The word "radiology" in this context can be confused with "radiation." Radiology is the branch or specialty of medicine that utilizes imaging technologies like x-rays, CT scans, and MRIs to diagnose and treat disease. Interventional Radiology (IR) is a sub-specialty of radiology in which minimally invasive procedures are performed using image guidance, which can include methods such as CT scans or tiny cameras that are inserted with a probe. Some of these procedures are done for purely diagnostic purposes, while others are done for treatment purposes. Images are used to direct these procedures, with the procedures usually done with needles, probes, tubes or other tiny instruments that look like small wires or tubes called catheters. In most cases these instruments are either inserted through the chest wall or guided down through the trachea and bronchus. The images provide road maps that allow the Interventional Radiologist to guide these instruments through the body to the areas containing diseases.
Brachytherapy / Bronchoscopy
Lung tumor treatment using brachytherapy involves several different methods, equipment and options. A bronchoscope is generally used for tumors in larger, major airways. It is a minimally invasive procedure that allows localized delivery of radiation therapy within the lung and can be used when a tumor can be seen in an airway. With a bronchoscopy, a thin plastic tube is placed down the nose, and down into the airways of the lung, into the bronchus area where the tumor is located. The bronchoscope is then removed, but the thin tube will stay comfortably in place for about 45 minutes during which time a radioactive pellet or rod will be deliverd down through the segment of the tube which is lying against the cancer. This effectively treats the cancer from the inside-out. Lung brachytherapy can be used to help with the following situations:
- Help open an almost-blocked lung airway
- Help stop bleeding
- Retreat a previously irradiated lung cancer
- Use in addition to regular external beam irradiation to increase the radiation dose and chance of stopping a tumor
- Use alone for the treatment of a lung tumor
For tumors located more deep lobe away from the air passageways, a needle delivery system can be used to insert a needle through the outer chest wall and deliver radioactive pellets or a radioactive probe into the tumor. Utilizing CT scans as part of the treatment planning and delivery the needle delivery can be very precise.
Methods of brachytherapy delivery include delivery of a radioactive source through a nasal catheter placed into the lungs using a bronchoscope; needle delivery direct implantation of radioactive seeds into the tumor area; a needle/probe inserted directly into the tumor; image-guided implantation of radioactive sources; and transbronchial source implantation with a bronchoscope.
Brachytherapy radiation source may be either temporary or permanent:
In temporary brachytherapy, (see also Afterloading Therapy) the radioactive material or probe is placed inside or near a tumor for a specific amount of time and then withdrawn. Temporary brachytherapy can be administered at a low-dose rate (LDR) or high-dose rate (HDR) and can be done in one treatment or spread out over several days.
Permanent brachytherapy, also called seed implantation, involves placing radioactive seeds or pellets (about the size of a grain of rice) in or near the tumor and leaving them there permanently. After several weeks or months, the radioactivity level of the implants eventually totally diminishes. The inactive seeds then remain in the body, with no lasting effect on the patient.
Afterloading treatment (also called interstitial brachytherapy) is a procedure in which a highly radioactive source (Iridium 192). During a short local anesthesia, hollow needles (applicator/catheter) are guided by a CT into the lung through the chest from the outside into the tumor. The radioactive source is then automatically inserted into a natural cavity into the applicator in the immediate vicinity of the tumor and radiation is emitted.
After the procedure the radioactive source and its applicator are removed automatically. The dose diminishes steeply around the treatment field so that the surrounding tissue is minimally affected.
The side effects of this treatment approximately equal those of seed implantation with transient.
Radiofrequency ablation (RFA)
RFA is a minimally invasive treatment usually for liver and lung metastases. A needle-like electrode (RFA probe) is inserted through the chest and guided to the tumor, using ultrasound or CT imaging. Once the probe is placed in a the tumor, the radiofrequency energy is deliverd, causing heating to the cancer and a small area of lung immediately surrounding this. That effect is localized so distant healthy tissue is not destroyed. The dead tissue will shrink later and gradually be absorbed by the body and replaced with scar tissue.
Temperatures applied can rise to 110 degrees Celsius (230 degrees Fahrenheit). Cancer cells will start to immediately die at 60 degrees Celcius. Each RFA treatment takes 10 to 30 minutes depending on the heat applied, the size of the tumor and the location. The entire procedure can take longer.
Generally up to 6 mets can be treated in one of the lungs in one treatment. It depends much on the circumstances during the RFA treatment. If uncommon complications occur only 2 or 3 mets can be treated.
After the cancer cells are killed, they shrink and turn to scar tissue over time. But sometimes the treated met after a few months seems to increase in size because of the scar tissue surrounding it.
RFA Brachtherapy and Afterloading have a common risk of pneumothorax (air getting into the chest cavity). The risk is similar to a CT guided lung biopsy procedure. This common complication is normally not serious and usually goes away on its own with no treatment. But even if the patient needs a chest tube to drain the air, the patient can usually go home after 2 or 3 days in the hospital. Some patients may experience some discomfort or pain the the treatment area for a few days and may also have a slight temperature and feel a bit tired and weak. Sometimes some patients will spit some blood for a few days. All this is not a serious complication though. Some other more rare side effects (e.g. bleeding, air leak taking long time to heal, injury of a nearby organ, flu-like fever) may occur.
Microwave Frequency Ablation (MFA)
Microwave ablation is a minimally invasive, image-guided technique that uses heat generated by microwave energy to destroy tumors. Rhode Island Hospital physicians became the first in the United States to use microwave ablation to treat cancer and are one of only ten facilities in the country that offer the treatment.
PDT (Photodynamic Light Therapy)
Photodynamic therapy (PDT) is a medical treatment that uses a photo-sensitizing drug (a drug that becomes activated by light exposure) and a light source to activate the applied drug. The result is an activated oxygen molecule that can destroy nearby cells. Precancerous cells and certain types of cancer cells can be treated this way. The procedure is easily performed in a physician's office or outpatient setting. PDT essentially has three steps. First, a light-sensitizing liquid, cream, or intravenous drug (photosensitizer) is applied or administered. Second, there is an incubation period of minutes to days. Finally, the target tissue is then exposed to a specific wavelength of light, which then activates the photo-sensitizing medication.
Cryoablation is the freezing of cancerous tissue by the use of liquid nitrogen or argon to extremely low temperatures. Bu using a small probe it is a minimally invasive, non-surgical procedure. Like Brachytherapy or RFA, the probes are inserted through the skin into the tumor. Basically, extremely cold gas is pumped through the needle into a tumor which causes the cancer cells to die by freezing. This procedure also has potential side effects. The major risk is pneumothorax.