Can RT side effects come in "waves"?

I had a high dose of external beam radiation — SBRT, specifically — and have radiation cystitis (bladder) and proctitis (rectum) that seem to be permanent.

I've also noticed that the sensations tend to ebb and flow, even though the damage is constant. Different foods, UTIs, dehydration, or even just stress can exacerbate one or both of them.

But also, I've gotten used to them (the radiation was May–June 2022), and wouldn't count them among the biggest challenges from cancer and cancer treatments.

Jeez, north - I'm sorry to hear that. Thanks for your encouraging reply.

Thanks.

I went into it with my eyes open. With my stage-4 diagnosis in 2021, I told them wanted to fight, so I got 60 gy of SBRT to my prostate (about the maximim allowed) in addition to my other treatments.

It's good that the radiation spread a bit beyond the prostate to catch any nearby cancer, but that also meant taking some collateral damage. I can live with that.

@mario326 here is what chatgpt answered when I asked it your question:

Yes, side effects from prostate brachytherapy can come in waves, meaning they may fluctuate or appear intermittently over time. This variation is influenced by several factors, including the type of brachytherapy (low-dose rate [LDR] or high-dose rate [HDR]), the stage of recovery, and individual differences in how the body heals.

Common Side Effects and Timing
Urinary Symptoms
Symptoms like increased frequency, urgency, difficulty urinating, or burning during urination can peak within the first few weeks or months post-treatment.
They may lessen over time but can recur intermittently, especially if triggered by factors like dehydration, urinary tract infections, or physical activity.
Bowel Symptoms
Symptoms such as rectal irritation, diarrhea, or rectal bleeding may fluctuate. Some individuals experience delayed onset of bowel issues, which can appear months after treatment.
Irritation can be exacerbated by dietary factors or constipation.
Erectile Dysfunction
Changes in erectile function may develop gradually over months or even years after treatment. Fluctuations can occur based on overall health, stress, and other treatments (e.g., hormone therapy).
Fatigue
Fatigue often peaks shortly after treatment and improves over weeks or months. However, it can return temporarily during times of stress or physical exertion.
Urinary Retention or Strictures
Scar tissue or inflammation can cause urinary issues to recur months or even years after treatment.
Long-Term and Late-Onset Side Effects
Some side effects, such as fibrosis, changes in tissue elasticity, or chronic inflammation, may manifest long after the initial recovery period. These late-onset effects can present as new or recurring symptoms.

Management Strategies
Monitor Symptoms: Keep track of symptom patterns and discuss them with your healthcare provider to determine if intervention is needed.
Lifestyle Adjustments: Staying hydrated, maintaining a balanced diet, and avoiding irritants like caffeine or spicy foods can help manage symptoms.
Medical Interventions: Medications (e.g., alpha-blockers for urinary symptoms) or procedures may be recommended for persistent or bothersome issues.
If your symptoms fluctuate significantly or new issues arise, it's essential to consult your healthcare provider for tailored advice and to rule out other potential causes.

@mario326
Did you have the high dose or low dose (side affects) treatments? Are you on hormone treatments (fatigue,etc.)?

My Mayo PCP does on going research on prostate treatments. He stated to me during last visit that research is showing more increased in degree of side affects when getting high dose radiation. You would think this would be just comon sense since body is getting bombarded with a higher dose of radiation.

The side affects during radiation are common but not all respond to radiation like others do. What maybe a problem with one patient will not be a problem with anohter. Thus know that your body and your treatments is specific to you and your radiation treatment plan.

Talk to your R/O about your concerns. Do you have a good experienced PCP that could help with questions or referr you to a specialist to help.

What I found, and again my body my specific treatment, was I did have side affects but were not serious. I did have some fatique that started about half way through (30 rounds of proton) treatments but did not allow it to stop me exercising and I think that helped me through it. I also developed increased urination, urgency and leaking.

All of these improved some right after treatments stopped and others taking over a year.

Like you, I had LDR brachytherapy (early October). Then, twenty-five treatments of IMRT (Tuesday will be the two week point of completion). I experienced significant bowel issues the first week after, urinary symptoms too. Bowel issues dropped off this past week. I had a couple of nights where I only got up once to urinate. Last night I was up every hour, go figure. Granted, it's a small, short sample.