Some of my experiences at work lately have reminded me of certain aspects of life as a multiple myeloma survivor. In both cases, decisions that can have major re­per­cussions must be made, sometimes on short notice, based on information that is at best sketchy, and at worst contra­dictory or misleading. While the details of the two cases are totally dif­fer­ent, the same sort of conundrum arises in both cases.

In multiple myeloma, a key decision that many patients face periodically is whether to continue with their current treatment or make some sort of change. The change may be to try a totally dif­fer­ent treatment, or modi­fying the dose or frequency of their existing medication(s). The moti­va­tion for this change can be to increase efficacy of the treatment against the disease, or conversely to reduce its side effects.

I am dealing with a minor form of this decision at the moment. I have been taking Revlimid ^[1] (lenalidomide) and the steroid dexamethasone ^[2] (Decadron) since 2014, ever since my IgA and kappa light chain numbers be­came too high for comfort. My oncologist and I tweaked my dosages and eventually came up with quite a good balance between myeloma control and side effects. I take 10 mg Revlimid on a cycle of three weeks on, one week off, plus 40 mg of dexamethasone once every four weeks.

As a result of this treatment, my numbers are now very stable. However, the side effects can still be somewhat annoying, particularly after such a long period on the treatment. Most everyone reading this will be familiar with the side effects of dex. Those of Revlimid are nowhere near as intense, but they occur more of the time. Since I am rather tired of these side effects, at the last meeting with my oncologist I asked if we could possibly try reducing my treatment. He suggested taking two weeks off, rather than the more usual one, after each three weeks of Revlimid.

This change in frequency does seem to have improved the side effects somewhat. I will find out at our next meeting in a few weeks what it has done to my multiple myeloma numbers. If things still look good, we might then also reduce the dex dose.

It is really only after the fact that a patient can know if their decision was a good one, and even then, it can still be debatable. Obviously, “safety first” is an important factor. Bad though it is to undergo a treatment with un­pleasant side effects, it is far worse to under-treat if it allows a relapse of the multiple myeloma. But, if excessively severe treatment were used, it could unnecessarily reduce the quality of life of the patient.

It is a difficult balance, and must often be made based on partial or contradictory information. For instance, readings such as M-spikes, levels of proteins, light chains, and heavy light chains almost never change in lockstep. One lab result may trend healthily downward or hold steady while another starts to increase. In such cir­cum­stances, it is difficult to be certain that any given decision on treatment options is the “right” answer.

At work recently, we have had to deal with a problem that reminds me of these treatment decisions. There are just so many objects in orbit these days that may collide with spacecraft. As well as active spacecraft, there are also defunct ones, old rocket stages, fragments of exploded rockets, and even nuts, bolts, and flakes of paint. (Yes, something as seemingly harmless as paint can be serious if it hits your satellite at many miles per second!)

My project is particularly sensitive to the collision question as we are flying four spacecraft in a formation that we recently reduced to only four miles across. We consequently have to make sure that we not only don’t hit some other object in space, but also don’t run two of our satellites into each other.

Spacecraft operators as a result always have be ready to “maneuver” their spacecraft, or fire their small rocket thrusters to push them to safety, if tracking data reveals the risk of an impact. It is a major disruption to do maneuvers, using precious fuel, requiring staff to come in (typically in the middle of the night!), and so on.

What makes the decision of whether or not to maneuver particularly difficult, and reminds me of the multiple myeloma situation, is that maneuvers require a lot of planning, and so the decision to do them must be made far ahead of time. Since this point in time is long before the spacecraft are actually close to each other, the decision must be made based on imperfect data: predictions of how close the satellites will come to each other some­time in the future. To make matters worse, the data from one prediction computer program will generally not be in perfect agreement with that produced by another. This disconnect in predictions makes it very hard to figure out which results to trust.

It is really only long after the fact that we know if our decision was a good one, and even then, it can still be debatable. Obviously, “safety first” is an important factor. Bad though it is to perform a maneuver that turns out to have been unnecessary, it is far worse not to maneuver and then have a collision. But, if a satellite ended up maneuvering all the time, it would basically not have any time to do anything else. If a space mission can be said to have a quality of life, it would be severely impaired.

Both the spacecraft and myeloma cases remind me of the well-known proverb “A man with one watch always knows the time. A man with two watches is never sure.” Of course, the proverb is somewhat tongue-in-cheek, as more data is almost always better. However, it doesn’t always feel like it!