Month: August 2023

When it comes to limiting side effects from radiation therapy, the name of the game is precision. Doctors want to treat the cancer while avoiding healthy tissues, and fortunately technological advances are making that increasingly possible.

One newer technique called stereotactic body radiotherapy (SBRT) can focus precisely targeted beams of high-dose radiation on a tumor from almost any direction.

The entire course of therapy requires only five individual treatments over two weeks, making SBRT more convenient than earlier low-dose methods that require more visits to the clinic. The treatment relies on specialized types of medical imaging scans that allow doctors to visualize where cancer exists in the body.

Advances in technology

Recently, doctors have begun to integrate SBRT with imaging scans that can visualize a tumor's movements in real time. Simple acts such as breathing, swallowing, or digesting food can shift a tumor's position. But this new technique — which is called magnetic resonance–guided daily adaptive SBRT, or MRg-A-SBRT for short — continually adjusts for those motions, so that doctors can focus more precisely on their targets.

Now, a new study helps to confirm that MRg-A-SBRT has fewer side effects than a related method called CT-SBRT, which uses computed tomography for imaging.

According to the study's lead author, Dr. Jonathan Leeman, a radiation oncologist at Harvard-affiliated Brigham and Women's Hospital in Boston, MRg-A-SBRT offers several advantages over CT-SBRT: one is that doctors using it can adjust treatment plans to account for a tumor's daily motions (this is called adaptive planning). The technology collects multiple MRI images per second during a radiation procedure, thus ensuring accurate real-time targeting. And finally, MRI visualizes the prostate with better resolution.

Analysis of studies

During the new study, Dr. Leeman and his colleagues searched the medical literature for every published clinical trial so far evaluating SBRT for prostate cancer, either with MRI or CT guidance. (This type of study is called a systematic review.)

The team ultimately identified 29 clinical trials that monitored outcomes for a total of over 2,500 patients. Short-term data on side effects was collected for up to three months on average after the procedures were completed.

Leeman's team used statistical methods to pool results from the studies into combined datasets. They found that the MR-SBRT-treated patients had fewer side effects. Specifically, 5% to 33% of men treated with MR-SBRT had genitourinary side effects, compared to between 9% and 47% of men who had the CT-guided treatments. Similarly, the risk of gastrointestinal side effects in the MR-SBRT-treated men ranged from 0% to 8%, compared to between 2% and 23% among men whose treatments were guided by CT.

Conclusions and comments

The authors concluded that "technical advances in precision radiotherapy delivery afforded by MRg-A-SBRT translate to measurable clinical benefit" (i.e., better tolerated treatments). But precisely why the treatments were better tolerated remains unclear. Is it because MR-scanning has better resolution? Did adaptive planning (and real-time targeting) account for the lower risk of side effects, or can that be attributed to some combination of all these factors? Dr. Leeman says that adaptive planning is "likely the main differentiator," but he adds that further studies are needed to confirm where the benefits come from.

To place this important work in perspective, we reached out to the authors of the new paper, as well as Dr. Anthony Zietman and Dr. Nima Aghdam, two Harvard-affiliated radiation oncologists who are also on the editorial board of the Harvard Medical School Annual Report on Prostate Diseases. All these experts feel this new technology has very promising potential.

But both groups cautioned that as with all newly developed innovations, results from additional studies — including clinical trials that are currentlyongoing — will be needed before more widespread uptake of the technology is warranted. Dr. Marc B. Garnick, the Gorman Brothers Professor of Medicine at Harvard Medical School and Beth Israel Deaconess Medical Center, says he "agrees with this conservative, yet optimistic assessment."

About the Author

Charlie Schmidt, Editor, Harvard Medical School Annual Report on Prostate Diseases

Charlie Schmidt is an award-winning freelance science writer based in Portland, Maine. In addition to writing for Harvard Health Publishing, Charlie has written for Science magazine, the Journal of the National Cancer Institute, Environmental Health Perspectives, … See Full Bio View all posts by Charlie Schmidt

About the Reviewer

Marc B. Garnick, MD, Editor in Chief, Harvard Medical School Annual Report on Prostate Diseases; Editorial Advisory Board Member, Harvard Health Publishing

Dr. Marc B. Garnick is an internationally renowned expert in medical oncology and urologic cancer. A clinical professor of medicine at Harvard Medical School, he also maintains an active clinical practice at Beth Israel Deaconess Medical … See Full Bio View all posts by Marc B. Garnick, MD

It’s tempting at this time of year to let summer sleep schedules stay in place or let bedtimes slide, especially when parents feel tired out, too. But it’s important that children have a regular routine — and that they are sleeping during the dark hours and awake during the light ones, as our bodies do best that way. That’s true for families who are home-schooling, as well: even when the trip to school is just a walk to the kitchen table, allowing for more sleep than those catching an early bus may get, no child should be spending all morning in bed.

Sleep is crucial for all of us, and this is particularly true for children. Without enough quality sleep, children are more likely to have health and behavioral problems — and difficulty learning.

Here are a few simple things you can do to help your child get the sleep they need.

Have a regular schedule

Our bodies do best when we go to bed and wake up at roughly the same time every day.

• Children and teens need eight to 10 hours of sleep. Count back 10 hours from when your child needs to get up in the morning. That’s roughly the time they need to be getting ready for bed (for younger children, count back 11 hours).
• For example, if your teen needs to be up at 7, then they should be getting ready for bed by 9, and in bed by 10 (since most of us don’t fall asleep the moment our head hits the pillow). A younger child should start getting ready (bathing, etc.) by around 8.
• Understand that teens are biologically wired to fall asleep later and wake up later and will naturally have later bedtimes. Unfortunately, most school districts don’t accommodate to this, so you are often working against biology.
• While it’s okay to stay up a bit later on weekends, don’t let the bedtime vary by more than an hour or so.

Turn off the screens before bed

The blue light emitted by screens can keep us awake.

• It’s best if the screens can be off two hours before you want your child asleep. Use that time when they start getting ready for bed as the time that the screens go off.
• The only real way to achieve this is to get all devices out of the bedroom. (So true!)
• Teens will fight you on this. If you can, hold firm (and buy them an alarm clock if they say they need their phone for this). At the very least, be sure that the phone is on Do Not Disturb mode overnight.

Have an environment that encourages sleep

• Quiet things down. If you are watching TV, turn the volume down, and in general try to not make much noise after children go to bed.
• Consider a white noise machine, or a fan (or air conditioner if you live somewhere warm). There are also white noise apps for those teens who won’t give up their phones.
• Room-darkening curtains can make a difference for children who tend to wake up at the first light of dawn — or who can’t fall asleep if it’s not fully dark outside.

Know how other factors influence sleep

• Busy teens often have difficulty getting everything done in time to get enough sleep. Talk with your teen about their daily schedule and look for ways to help them get more shut-eye, such as getting homework done during the school day, or limiting video games or other activities that eat into homework time. Sleep needs to be the priority.
• Limit caffeine. It’s best not to have any, but certainly nothing from mid-afternoon on.
• Limit naps! For a tired older child naps may seem like a good idea, but they can interfere with nighttime sleep. Naptime is okay through preschool.
• Make sure your child gets exercise. It’s not only important for their health, it helps their sleep.
• Have calming routines before bed (not exercise!).

If your child is having trouble falling asleep, or is waking up at night, talk to your doctor. It’s also important to talk to your doctor if your child is snoring or having other breathing problems at night. Don’t ever ignore a sleep problem; always ask for help.

About the Author

Claire McCarthy, MD, Senior Faculty Editor, Harvard Health Publishing

Claire McCarthy, MD, is a primary care pediatrician at Boston Children’s Hospital, and an assistant professor of pediatrics at Harvard Medical School. In addition to being a senior faculty editor for Harvard Health Publishing, Dr. McCarthy … See Full Bio View all posts by Claire McCarthy, MD