Clodronate. And how to deal with emerging Radiation Induced lumbo-sacral plexopathy?

[MateoBeach]

First the personal and then the science: I completed PLN RT to left hemipelvis about a year ago (58Gy in 28 fractions with boost to two PSMA avid nodes. Thee months or so after the RT I developed left sacro-iliac joint and adjacent muscular pain. Bothersome but did not impair my functioning. I had L-S spine high-res MRI in October showing no cancer in the area but swelling/inflammation of pyriformis and iliacus muscles. That accounts for the pain and I though consistent with some radiation spillover. That is now down about 60%.

However, I have now developed more severe pain in my left anterior-lateral thigh (predominantly L-4 distribution) which is claudication like (increases with walking 3 to 5 minutes to excruciating, then rapidly relieved by stopping 30 seconds). No other neurologic symptoms yet except hypesthesia at times over the L4 area (front-lateral thigh). Research suggest the possibility of Radiation Induced Peripheral Neuropathy (specifically LS plexopathy) as a possibility. This has me very worried as it can be permanent.

Treatments that may help to devend against its progression include: Corticosteroids (short term moderate dose like dexamethasone 5 mg BID); The combination of petaxofylline (trental) with alpha tocopherol Vitamin E at 1,000 IU/day; And perhaps the bisphosphonate clodronate. However this is not approved in the USA only a veterinary preparation apparently. My strategy for addressing this promptly is pentaxofylline 400 mg BID with Vit E 1000 IU/day (my RO agrees).

And perhaps adding a bisphosphonate, if not Clodronate then perhaps Alendronate at 70 mg/week.

In my research I came upon more that suggests that bisphosphonates may reduce (prevent) metastasis to bone by impairing the micro-environment for bone mets. This is a concern for all of us with advanced PCA. This includes consideration of Zometa as well as for Prolia. Your thoughts??

[Tall_Allen]

Zometa definitely does not reduce progression on its own. However, it seems to have some effect when combined with Celebrex in men with bone metastases.

[MateoBeach in reply to Tall_Allen]

Thank you. I am on celecoxib and also Prolia. No bone mets on scans yet. Any likely value in adding or switching to a bisphosphonate?

[Tall_Allen in reply to MateoBeach]

The combo had no benefit in men who didn't have metastases on a bone scan. If your BMD is normal on a bone scan, you should avoid these drugs.

[LearnAll]

MateoBeach,Bi-phosphonates do reduce Osteoclastic bone resorption and consequently bone repair by osteoblastic manner. A hallmark of Bone metastases.

Once the bone is stronger and more solid, the mets have difficulty forming due to change in microenvironment. . Besides it controls bone pain beautifully in those who have bone pain.

But before going to infusions of biphosphonates or Rankl inhibitors, I would prefer oral bi-phosphonates for two reasons. One, it gives more control on dosage and two ..it possibly has less chances of very serious side effects such as Osteonecrosis of jaw. Besides that I want to do Bi-phosphonate Intermittently guided by bone density measured by DEXA Scan.

I have been able to keep my bone density in normal range for last 18 months just by daily Vit D-3+ K2, Black and Green tea blend (3-4 cups a day), Turmeric 30 grams a day, strontium, Dietary Calcium and cardio and resistance exercise 5 to 6 times a day. I have not needed any medicine for bone density yet. If I need in future, my first choice will be Alendronate 10 mg a day. There is hardly any difference between clodronate and Alendronate.

[MateoBeach in reply to LearnAll]

Thanks. Good info. In this situation clodronate appears to interrupt the fibrosis aspect of evolving radiation neuropathy. So wondering if I should add in alendronate for the immediate term even though I’ve been on Prolia and calciums are normal. I am going to start the pentaxofyllin and Vit E tomorrow and started some steroid , dexamthasone 5 mg twice daily for a short course. Here in Mexico I’m flying by seat of my pants. ✈️

[LearnAll in reply to MateoBeach]

Yes..for short term...IMO..there is no harm in adding alendronate 10 mg a day (or 70 mg a week) Long term its better to pick either biphosphonate or Rankl Inhibitor.Side effects of these meds are cumulative...uninturrupted long term use causes more side effects.

[MateoBeach in reply to LearnAll]

Just re read this and feel I must be such a slacker. I do one cup of coffee and exercise daily cardio-endurance and lift weights twice a week. Nothing but water and my supplements and meds until Dinner time. You, on the other hand are a champ! 👍🏼👍🏼👍🏼👌👌“just by daily Vit D-3+ K2, Black and Green tea blend (3-4 cups a day), Turmeric 30 grams a day, strontium, Dietary Calcium and cardio and resistance exercise 5 to 6 times a day“

[LearnAll in reply to MateoBeach]

I do not lift heavy weights...I use ankle and wrist weights which I bought from Amazon ..I tie these weight and walk and run with them...it works as resistance exercise and cardio both. Also ,a lot of yoga, stretching exercises. My bone density scan is unchanged from 12 months ago..in fact some what better.Not taking any prescription med for bones.

See the COMB protocol :ncbi.nlm.nih.gov/pmc/articl...