Do you typically recommend avoiding neupogen during radiation treatments?

It depends on the reason and expected benefit.

If myelosuppression is holding up RT for cervical cancer patients, then I would not hesitate to give neupogen to avoid or minimize a treatment break. There would be more benefit to neupogen and continuing RT than a downside. Usually, I would try to give on Friday, Saturday, and Sunday and resume RT by Monday.

Generally speaking, it is our institutional practice to not hold RT for neupogen/neulasta administration. The only times we would consider is if the patient has a concurrent neutropenic fever.

The history behind holding RT during neupogen administration originated in the era of 3D techniques. For example, with lung cancer, it was in the era of an AP-PA followed by an off cord boost. Modern techniques of radiation therapy are much more conformal and as a result, overall bone marrow dose is lower now than it has ever been in the past. As a result, RT 'counteracts' neupogen much less than in the past.

This myth that growth factors cannot be safely combined with RT was tested in the 2D era by a protocol done at the JCRT adding etanidazole to chemoradiotherapy for patients with esophageal cancer. We gave patients G-CSF during the weeks they did not receive chemotherapy. This was effective in keeping the WBC up and did not add side effects, even though we were usually treating more or less the entire thoracic spine. (See: Buswell et al., PMID 8005812.) So, combining RT with growth factors likely is even less of a problem in the era of highly conformal therapy.

I am still reluctant to add growth factor support during thoracic radiation. Dr. Lilenbaum published in the Journal of Thoracic Oncology in 2010 a phase II trial incorporating colony-stimulating factors to platinum etoposide thoracic radiation with consolidation docetaxel. 26% of patients had grade 3 or 4 pneumonitis. This contrasts to a similar regimen published out of the Hoosier Oncology Group without the growth factor support (Barriger et al.) where grade 2-5 pneumonitis was seen in 7% of patients. The consolidation docetaxel was associated with more pneumonitis in this randomized trial but I think there is reason still to be cautious with thoracic radiation.

To revive an old question! Has anyone's practice changed since the publication of the subset analysis evaluating the use of G-CSF in the phase 3 CONVERT trial (Gomes et al., PMID 33545577)? There appeared to be no difference in radiation-related toxicity, mortality, or survival whether or not patients received concurrent G-CSF.

They do comment on how the 2006 ASCO guideline recommending physicians avoid concurrent G-CSF in thoracic radiotherapy is based off an older trial from the 90s where patients received GM-CSF (not G-CSF) which may have contributed. It was also noted that ESMO guidelines support the use of G-CSF with concurrent thoracic chemoradiotherapy.

I agree that we don't hold RT if the patient has been given Neupogen/Neulasta but I encourage the medical oncologists not to give it for the reasons given by @Dr. First Last. When the neutrophil count falls below 500, I will recheck the WBC in 2-3 days and continue radiation as long as the neutrophil count isn't dropping. If I do give an RT break (which doesn't happen very often), it is often on a Friday so that hopefully rechecking on Monday allows the resumption of therapy.