Ten things you should know about radiotherapy for bone metastases

Grandma A'e, 68, is a patient with stage 4 lung cancer. She has received targeted drug treatment with Aretha before. She has been following the medication at Dr. Huang's outpatient clinic and her condition is not bad. Stablize.

However, in the past few weeks, Grandma A'e has always complained to her daughter that her lower back is getting more and more painful. Sometimes she sleeps until midnight and wakes up from the pain. Grandma A'e said, Most of the pain is dull, with occasional throbbing pain.

The pain is worse at night than during the day. When I lie down to rest, my back seems to be more comfortable, but when I change positions, it will be particularly painful.

After hearing this, Dr. Huang quickly arranged a "nuclear medicine full-body bone scan" for her mother-in-law.

"Mother-in-law, the bones in the waist look a little weird when taking pictures. I will transfer you to the radiation oncology department and ask the doctor to evaluate you and see if you need any treatment. "Doctor Liu pointed to the black spots on the film and said softly to Grandma A'e.

"Oh... OK." Grandma A'e responded and followed her daughter Zhenqing to my clinic.

"Hello, Dr. Chen, we meet again." Zhen Qing said softly.

Having just read the medical records, I raised my head and exchanged glances with Zhenqing. She slightly pursed her lips in sadness.

I turned around and looked at Grandma A'e. I clicked on the bone scan image with my mouse. The screen showed that there were two obvious black spots on the left side of the third and fourth lumbar vertebrae.

"Hello, grandma, have you been feeling unwell lately?" Grandma A'e had come to the department for radiation treatment for a lung tumor before, so she was familiar with the environment here.

"Here...it hurts here! It hurts especially at night! Also, the left foot will be slightly numb, and sometimes it will hurt all the way from the waist..." Granny A'e held her left lower back. explain.

"Can the left foot be raised?"

Granny A'e quickly moved her foot. "It should be okay, it's only a little tight...but I feel that my left foot is relatively weak, and sometimes it becomes a little soft after standing for a long time."

Granny A'e's feet can be bent and straightened smoothly. I asked Granny A'e to bend her feet, and then try to straighten them to push away my palm that was on the sole of her foot.

"Is that so?" Although my mother-in-law is not as strong as an average adult, she can still push my hand away, but at a slower pace.

"Mother-in-law, let us arrange another examination for you. After the examination, we will use X-rays to help you do some treatment to reduce your pain, okay?"

"Okay, doctor, just help me make arrangements. As long as it doesn't hurt, it'll be fine...!"

I winked at Zhenqing, and she slowly knelt down and spoke to A'e softly. The mother-in-law said: "Mom, please sit outside first, and the doctor will tell me what tests to do."

Grandma A'e always listened to Zhenqing's words, and held her hand with squinted eyes. Keep nodding. "Okay, okay, I'm going to rest."

When Granny A'e left the clinic, Zhenqing sighed softly, turned around, pulled out a chair and sat down.

"Based on the current preliminary examination, the nerve compression should not be too serious. If the MRI examination does not find obvious nerve compression, we will treat the mother as soon as possible."

"Radiation therapy is not the main treatment method for mothers now. When the tumor has progressed to metastasis, it usually means that the cancer cells no longer stay in their original place, but will move along the blood circulation. External spread; therefore, the main focus of bone metastasis treatment will be systemic treatment. The main purpose of radiation therapy is to help the mother reduce local pain. In addition to improving the mother's quality of life, the pain relief will also be improved. There will also be an opportunity to lower the dosage of the medicine, which can somewhat alleviate some of the discomfort caused by the medicine." I continued.

"Um...Okay." Zhenqing answered briefly, with worry on her face.

"Don't be impatient. We will discuss follow-up treatment strategies with you after the examination results come out. Generally, radiotherapy has a good effect on pain relief, and there should be a chance that the mother's pain can be improved. We will discuss it later. Let me tell you what problems you may encounter during radiotherapy for bone metastases. ”

Bone metastasis is a common problem faced by patients with advanced cancer. Although bone metastasis itself is rarely fatal, However, the pain, compression fractures, hypercalcemia, etc. associated with bone metastasis will significantly affect the patient's quality of life and mobility.

When mobility is affected, the patient's physical strength will deteriorate, and he or she may even be bedridden and unable to walk for a long time. It also makes subsequent treatment more difficult. Therefore, if bone metastasis can be properly treated, related complications can be reduced and the patient's quality of life can be improved.

Next, let us take a look at ten things you should know about radiotherapy for bone metastases.

Q1: What exactly is bone metastasis?

When cancer cells enter the advanced stage of the disease, the genes in the cells will undergo many mutations. After the mutations, some cancer cells will "immigrate" from their original location to bones throughout the body, and then When another tumor grows into the bone and destroys the bone, we call it "bone metastasis."

Bones are the third most common location for distant cancer metastasis, after the lungs and liver.

All cancers may have bone metastasis, but bone metastasis from breast cancer, prostate cancer, and lung cancer accounts for approximately 70-80% of all patients with bone metastasis. ?

Bone metastasis may occur in all bones of the body, but the sites of metastasis are mostly concentrated in the spine (cervical, thoracic, lumbar), ribs, and pelvis. The thigh bone and upper arm bone are also prone locations for bone metastasis.

Generally speaking, bone metastasis rarely occurs below the elbow joint and knee joint.

Q2: Why does bone metastasis occur?

Rich blood flow: Metastasis of cancer cells often occurs in places with "rich and slow blood flow", such as the brain, lungs, liver and bones. If you have ever handled chicken or pork bones in the kitchen, you will have noticed that there is often a lot of blood in the middle of the broken bones. The bone marrow inside the bones is responsible for the hematopoietic function in the body, especially the "red bone marrow", so the blood flow inside the bones is very amazing.

Cancer cells like bones: This concept can be understood using the concept of "immigration". For example, the United States has such a large area, but most of the Asian immigrant population is concentrated in large cities on the east and west coasts. Why? Because for Asians, the "environment" of living in metropolitan areas on the east and west coasts allows them to enjoy a relatively comfortable life.

For cancer cells, the rich blood flow and strong growth factors in bones also make them feel more "comfortable". Therefore, when cancer cells flow through the bone marrow with the blood, they may combine with cells in the bones and stay in the bones.

Vicious cycle: Bones are rich in growth factors. When tumors activate osteoclasts and break down bones, these growth factors originally present in the bones will be activated, further causing the tumors to grow larger. Destroy bones.

Q3: Which tumors are prone to bone metastasis?

Breast cancer, prostate cancer, thyroid cancer, lung cancer and renal cell cancer. Patients with these types of cancer have a higher chance of metastasizing to the bones.

Head and neck cancer, as well as malignant tumors of the gastrointestinal tract, such as gastric cancer, colorectal cancer, rectal cancer, etc., are relatively rare in bone metastasis.

Q4: Does bone metastasis mean that my disease is serious?

Usually, if bone metastasis or other distant metastasis occurs, it means that the tumor cells have spread outward along the blood route. It is indeed very difficult to cure the disease theoretically.

However, the length of survival varies greatly depending on the type of cancer. It depends on what kind of cancer the patient has and whether there are distant metastases in other parts of the body, such as the lungs, brain and liver. Even with the same type of cancer, the length of survival varies greatly from patient to patient. For example:

Lung cancer: After metastasis to the bones, the median survival is about 6-8 months.

Breast cancer: Median survival after metastasis to bones is 20 months.

Prostate cancer: Median survival after metastasis to bones is 53 months.

Q5: Why does bone metastasis eat bones?

In fact, it is often not the cancer cells themselves that actually erode bones. In human bones, there are two special cells: one is called osteoclasts, and the other is called osteoblasts.

From the name of the cell, you can know its function. The function of osteoclasts is to "break down bone", while the function of osteoblasts is to "form bone."

In normal human bones, the activities of these two cells are in balance. Therefore, although our bones do not appear to have changed significantly in appearance, they are actually in "dynamic balance."

This means that the amount of bone broken down every day is similar to the amount of new bone formed, so bone quality remains stable.

But when the tumor migrates to the bone, it will act as a cheerleader for osteoclasts, causing this delicate balance to be destroyed. The activity of osteoclasts becomes stronger, while the activity of osteoblasts becomes relatively weak. , the bones become less and less.

When tumors grow, they will also destroy the structure of bones, thus reducing normal bone mass and causing bone erosion. However, the main impact of bone metastasis is still due to the tumor increasing the activity of "osteotrophic cells", rather than the tumor itself.

Q6: What discomfort will I feel during bone metastasis?

Local pain: The most common symptoms of bone metastasis are pain near the "metastasis site", as well as pain, soreness, numbness, or limb weakness caused by tumor compression or invasion of nerves.

In any cancer patient, if there is "new" pain, or "persistent" and "increasing" pain, they must be highly vigilant.

Due to the destruction of the bone structure, proliferating tumors will cause local inflammation and damage the periosteum, thus causing pain. Most metastatic tumors are located in the "axial bones" of the body, that is, the spine, tail vertebrae, pelvis, and long bones of the thighs and arms.

Because the axial bone needs to bear the weight of the body, when the structure is damaged, the spine will become unstable, causing the spine to collapse or the long bones to break because it cannot bear the weight of the body. This type of fracture caused by tumor bone metastasis is called "pathological fracture".

When the vertebrae collapse, the nerves passing between the two vertebrae are compressed, which can also cause pain. These pains may be aggravated by activity and are usually worse at night than during the day.

If the structural integrity of the bone has been destroyed by bone metastasis, surgery must be performed to reset the damaged structure to more effectively relieve pain.

Therefore, in addition to radiotherapy, the treatment of bone metastases also requires the expertise of orthopedics and neurosurgeons to handle it properly.

Spinal cord compression or nerve compression: The spinal nerves extend from the cerebellum to the waist. There are countless nerve cells in them, and they are wrapped in the bones of the spine.

If the bone metastasis in the spine grows and invades backwards, further compressing the spinal nerves, the patient may experience symptoms such as limb weakness, paralysis, abnormal sensation, numbness, abnormal urinary and fecal function, or incontinence. Emergency surgery may be needed.

Affects bone marrow hematopoietic function: Since the tumor occupies part of the bone marrow space, when the number of bone metastases is large, especially when the bone metastases are located in the lumbar spine or pelvis, it may affect the patient's hematopoietic function, resulting in Anemia, low white blood cells, or insufficient platelets.

Hypercalcemia: Certain tumors can significantly increase the decomposition of bone, releasing calcium ions into the blood. However, the symptoms of hypercalcemia are usually subtle and similar to those experienced by cancer patients, making them difficult to distinguish. This can be determined by taking a blood test to check the calcium ions in the blood. Symptoms that may occur when hypercalcemia occurs include: fatigue, headache, weakness, disturbance of consciousness, arrhythmia, nausea, vomiting, constipation, abdominal pain, polyuria, thirst, dehydration, etc.

Q7: How can radiotherapy for bone metastases help me? Will the pain stop immediately after taking the photo?

Radiation therapy for bone metastases has three main treatment purposes:

1. Reduce pain

2. Maintain the patient’s motor function and autonomous movement

3. Reduce subsequent complications caused by fractures or nerve compression

The main mechanism of radiotherapy for pain relief is not to completely eliminate all tumor cells. Instead, through the radiation, Return the disrupted balance between osteoclasts and osteoblasts to normal conditions.

After irradiation, about 65-80% of patients can experience partial or complete improvement in pain; among them, about 20% of patients can experience complete improvement in pain.

After irradiation, the pain usually does not improve "immediately", but the effect will be slowly seen within 2-3 weeks; about 40 patients can feel pain relief within 10 days.

If the pain does not improve significantly one month after the end of the first course of treatment, a second course of radiation therapy can also be considered within the "safe range" after evaluation by a physician. About 30 percent of patients have a chance of further relief.

Q8: How long does a course of treatment take?

The most common irradiation method is once a day (Monday to Friday), with 10-14 treatments, and the common total dose is 30-35 Gy.

For some patients with poor physical strength or a short expected survival time, it may also be considered to shorten the total number of treatments to 1 fraction (8 Gy) or 5 fractions (total dose 20 Gy).

The analgesic effects of each different method are approximately the same, ranging from 60 to 80. If you choose a single treatment, the chance that the same area will need radiation therapy again in the future increases slightly, to about 20%. For details, please ask your attending physician.

Q9: How will I feel about receiving radiation therapy for bone metastases?

Fatigue: If the patient has multiple bone metastases and the radiation range is wide, the feeling of fatigue will be more obvious.

Temporary intensification of pain: For about 30-40 patients, the pain will worsen (Pain Flare-Up) in the first few days of treatment, which lasts for about 1-2 days.

When radiation irradiates a tumor, it will first cause a temporary inflammatory reaction, causing local swelling near the irradiated site, damaging the surrounding nerves, and causing temporary worsening of pain; this situation can be treated by giving Oral steroid drugs to prevent or relieve.

Symptoms vary depending on the irradiation site:

Cervical spine: If the bone metastasis is located in the cervical spine, because the throat and esophagus are directly in front of the cervical spine, treatment will cause inflammation of the throat and esophagus. Therefore, after about 6-8 treatments, the patient will have a slightly hoarse voice, a foreign body sensation when swallowing, and may also experience pain in swallowing. But these symptoms usually improve over two weeks.

Thoracic spine: If the bone metastasis is located in the thoracic spine, because the esophagus, lungs and heart are directly in front, treatment will cause inflammation of the esophagus, lungs and pericardium.

? Esophageal inflammation: The general symptom is a foreign body sensation or pain when swallowing. Most patients will recover within 2-3 weeks.

?Pulmonary inflammation: Since the total therapeutic dose is only about 30-35 Gy, although the lungs may be slightly inflamed 1-2 months after irradiation, causing dry cough, fatigue during activity, or mild fever, It usually resolves on its own within 2-3 weeks.

?Pericardial inflammation: A few patients will have difficulty breathing, chest tightness, or breathing pain. However, because the total dose is not high, even if there are symptoms, they will usually subside within 2-3 weeks. improve.

Lumbar vertebrae and pelvis: Directly in front of the lumbar vertebrae are the internal organs and intestines in the abdominal cavity, so during irradiation, the internal organs and intestinal tracts will receive part of the dose. Because the total dose of treatment is only 30 Gy, the bladder, liver, kidneys, etc. are rarely affected by radiation therapy for bone metastases.

The more common one is mild gastrointestinal inflammation. Therefore, patients may experience symptoms similar to gastroenteritis such as mild abdominal cramping, increased bowel movements (but the chance of watery diarrhea is low), mild nausea, vomiting, and more.

Appetite may also become slightly worse, but this usually resolves within 1-2 weeks after treatment is completed. If the symptoms of nausea and vomiting are obvious, you can ask your doctor to prescribe medication to relieve your symptoms.

Limbs and joints: There may be slight swelling and tightness in the tissues near the irradiated site; there may be slight edema at the ends of the hands and feet, but this usually does not require treatment or treatment.

Skin: The irradiated skin will experience symptoms of dryness, itching, blackening and slight peeling in the second week of treatment, or 1-2 weeks after the end of treatment. The hair near the irradiated area will fall off.

Sudden spinal cord nerve compression: Rare. This situation more commonly occurs in patients who already have severe spinal cord compression and are physically unable or unsuitable for surgery.

Since most tumors will not shrink immediately when they first receive radiotherapy, but will first produce an inflammatory reaction and local swelling; when the spine has been too damaged by bone metastasis, serious When spinal nerves are compressed, the slight swelling caused by radiation therapy may worsen the compression and aggravate the neurological symptoms.

However, in this case, radiotherapy is actually no choice among choices. Although there are risks, there is a chance of improvement with treatment. If you are too worried about the risks and are afraid of receiving treatment, the tumor will eventually continue to grow and the spinal nerves will still be compressed.

However, in general, since the total dose of radiotherapy for bone metastases is not high, the side effects caused are mostly mild and last for a short time. If chemotherapy or targeted therapy is combined with radiation therapy, the severity of side effects may be slightly increased.

Q10: What other treatments might I receive?

Drug treatment

?Analgesics: In addition to using radiation therapy to deal with the painful part, drugs can also be added to deal with the patient's pain.

At the beginning, common oral analgesic and anti-inflammatory drugs will be used. If there is a poor response to traditional anti-inflammatory drugs, the doctor will prescribe weak morphine drugs. If the pain intensity continues to increase, the doctor will replace the weak morphine drugs with stronger morphine drugs or a pain patch.

?Steroids: can be taken orally or intravenously. Steroids can reduce swelling, stop vomiting and reduce inflammation.

Bisphophonate: After injection, about 50-75% of this type of drug will adhere to the surface of the bone after intravenous injection. When osteoclasts break down bones, they take bisphosphonates along with them. For "osteotrophic cells", bisphosphonates are like deadly poisonous alcohol, so the osteotrophic cells will die and decompose. In this way, the destruction of bones by osteoclasts can be reduced.

?RANKL monoclonal antibody (Denosumab): The trade name is "Prolia" or "Xgeva". Its function is to combine with "RANKL" and prevent RANKL from corroding bones. The combination of cells. RANKL is like a nutrient for osteoclasts. After Denosumab injection, osteoclasts lack a source of nutrients and cannot differentiate properly and become mature osteoclasts, which will lead to a reduction in the number of osteoclasts and bone destruction. It can be alleviated naturally.

Surgical treatment

When the patient's tumor causes instability in the spinal structure, compresses the spinal nerves, or causes serious damage to the load-bearing bones (such as the spine or lower limb bones), the patient has (or will soon) Possible) When a pathological fracture occurs and surgery is needed to assist in reduction (or prevention), surgery can be considered.

Surgery can relieve pain relatively quickly, relieve compression symptoms more immediately and quickly, and can also speed up the patient's recovery. If deemed appropriate by a neurosurgeon or orthopedic surgeon, surgical treatment may be considered.

Generally, after surgical treatment, additional radiation therapy will be given to the surgical site.

Vertebroplasty or Kyphoplasty

Using image guidance, a hollow needle is used to inject low temperature into the spine where compression fractures occur. Bone cement is a low-invasive treatment that relieves pain and stabilizes the spine.

The difference between the two is that in kyphoplasty, water balloons are used to hold up the space before bone cement is injected; while in vertebroplasty, bone cement is injected directly.

The bone cement will harden quickly within 15-20 minutes after injection, which can fuse the broken bone fragments, reduce sliding, and have a chance to relieve pain. Suitability for the procedure needs to be evaluated by a radiologist.

Systemic anti-cancer treatment

Including chemotherapy, targeted therapy, anti-hormone therapy, and immunotherapy, etc., if effective against tumors, they can also achieve analgesic effects. However, systemic anticancer treatment usually slows pain relief.