Is it acceptable to use once daily fractionation for small cell lung cancer?

This question is still very relevant of further discussion. This particular poll and commentary began in June 2016! For the record, as of today I still prefer 45 Gy in 30 fractions delivered BID. For those that cannot come to treatment twice-daily, I use 60-66 Gy in 30-33 fractions based on OAR constraints.

There are two new datasets that will impact the twice-daily versus once-daily decisions of oncologists treating limited-stage small cell lung cancer. The first is an impressive randomized phase II trial from Scandinavia by Groenberg et al published in Lancet Oncology 2021. This trial compared 45 Gy in 30 fractions versus 60 Gy in 40 fractions and showed an impressive overall survival benefit in the 60 Gy arm; (HR 0.61). The two arms were...

It is no accident that both the RTOG/CALGB and CONVERT, the latter completed in the summer 2013, used 45 gy BID in 3 wks as the control arm. Nothing else has proven better. @Dr. First Last discloses some information of an NCIC study using 40 gy close to the Canadian HypoFx for breast, used in SCLC in the 1980's. Let's see the paper, but this is the direction I have used for refuseniks for BID. Instead I use 45 Gy/3Gy/3wks with many dosimetric magical tricks to lower cord and esophagus dose. I also use that in ED. And in NSCLC for aggressive palliation. Protracting TRT will prove to be more toxic, more expensive and less effective, but I am willing to wait for the data. Treatment planning has reduced toxicity immensely, but 45 Gy BID/3 wks h...

Another alternative would be 40 Gy in 15 fx per NCIC and London Lung Cancer Group studies. A recent randomized trial should be published soon demonstrating no difference between 45/30 bid and 40/15 qd in terms of survival. This hypofractionated course has not been compared to the phase I/II CALGB data exploring 70 Gy in 35 fx noted by Dan above, and unfortunately is not in the ongoing randomized CALGB/RTOG trial (70 Gy/35 fx vs. 45 Gy/30 bid, recently dropped the 61.2 Gy integrated boost arm). I am particularly fond of these abbreviated courses for patient convenience, and the fact that the chemo is the backbone of therapy and therefore preventing toxicity related treatment interruptions is optimal. In light of RTOG 0617 data, I also have a...

Indeed I have seen the slides [CONVERT trial, presented at ASCO 2016] and while not published, cycle 2 plat/etop concurrent with 45 Gy bid in 30 fractions over 3 weeks and 66 Gy QD in 33 treatment days in 6 + weeks have similar survival, same local control, and similar esophagitis. However, the trial was designed to show QD to be better, producing a significant survival benefit. It also showed no inability to maintain dose intensity. The difference showing a slight BID benefit would have required 500 more patients. So for now, the QD dose is 66 Gy.

Some claim BID is "inconvenient." Reporting that 33 treatment days is more convenient than 15 will be rather interesting. Prof Faivre-Finn says she is sticking with BID. Frankly, I will too. But ...

I routinely treat small cell lung cancer with QD fractionation (2Gy x 30) with concurrent chemotherapy. I work in a "safety net" hospital where most of the patients rely on volunteers or other public service to get to/from the hospital for treatments. When I started working here, I though BID would be a slam-dunk: patients would only have to come for three weeks. But it ended up that the patients would miss more BID days than they would make because of late/cancelled rides, or other various reasons. So after a few tries, I just went to daily fractionation. I don't use 70Gy because I find it counterintuitive that we would be treating small cell lung cancer (a radiosensitive tumor) to higher doses than non-small cell lung cancer (now that we ...

Although it is entirely anecdotal, in my practice I have yet to see a 5 year survivor treated with once daily fractionation for curable SCLC. The only survivors have been treated with BID fractionation to 45 Gy. I keep the patients in the clinic if they have travel challenges, feeding them, etc. I understand @Dr. First Last's challenges at a safety net hospital in Boston but I treat in Appalachia (WV) and I guarantee my patient's challenges are difficult to beat. In terms of the increased esophagitis rates with BID, I give sc Ethyol prior to the pm dose and have found it very well tolerated and quite effective. I treat per the Turrissi protocol with the pm dose obliques off cord (after the intial 15 Gy) to help with the esophagitis.

I would use 70 Gy in 35 fractions, which is the experimental arm on the ongoing RTOG trial comparing dose regimens.