Facial cutaneous carcinoma HDR contact brachytherapy with customized molds
ForFacial BCC/SCC ≤3 mm thick, ≤4 cm, mostly elderly, non-surgical
TL;DR5-yr actuarial LC 89% (100% flat surfaces, 83% nose) with Ir-192 HDR contact mold BT, 48 Gy/12 fx, for facial BCC/SCC ≤3 mm thick.
Failure tracked the applicator, not the dose: all five relapses had only three catheters, and four sat on the nasal tip (LC 73%) versus 95% on pyramid/wing and 100% on flat skin. The 3 mm prescription depth only fits lesions ≤3 mm, so nasal-tip lesions or thicker tumors argue for electrons, interstitial BT or surgery.
In an elderly pt with a thin (≤3 mm) facial BCC/SCC on the temple, forehead, cheek or nasal dorsum/ala, this supports HDR contact mold BT as a surgical alternative; it does not extend to nasal-tip lesions or tumors thicker than 3 mm.
Failure tracked the applicator, not the dose: all five relapses had only three catheters, and four sat on the nasal tip (LC 73%) versus 95% on pyramid/wing and 100% on flat skin. The 3 mm prescription depth only fits lesions ≤3 mm, so nasal-tip lesions or thicker tumors argue for electrons, interstitial BT or surgery.
12 details
Retrospective single-institution series, 51 lesions in 48 pts referred 1999-2005. Median follow-up 45 mo (range 4-102); LC by Kaplan-Meier.
Facial BCC (82.4%) and SCC (17.6%), mean diameter 1.5 cm (0.5-4 cm), thickness ≤3 mm in all; thicker lesions went to electrons. Median age 78; 95% radical, 5% adjuvant after lateral-margin-positive excision.
Ir-192 HDR contact BT via custom wax nasal molds (CT-planned) or bolus applicators on flat skin, 1 cm margin, prescribed at 3 mm depth. Standard 48 Gy in 12 fx of 4 Gy, 3 fx/wk, over 4 wk; 3 Gy x 17-18 and 7 Gy x 5 schedules also used.
5 relapses (9.8%) at 6-32 mo, all on the nose and all with three-tube applicators. Nasal tip LC 73% vs 95% on pyramid/wing; all salvaged surgically.
| Schedule | Share of cases | EQD α/β10 | EQD α/β2.5 |
|---|---|---|---|
| 44-48 Gy, 4 Gy x 11-12 fx | 57% | 57.75-63 Gy | 61.5-67 Gy |
| 51-57 Gy, 3 Gy x 17-18 fx | 37% | 62-69.3 Gy | 61.2-64.8 Gy |
| 35 Gy, 7 Gy x 5 fx (very old pts) | 6% | 55.5 Gy | 72 Gy |
Acute G4 dermatitis in 11 pts (21%), healed within 3 wk; no late complications including chondritis. Cosmesis good or very good in all cases.
Source cites Guix et al. contact HDR-BT with 5-yr LC 98% at 60-65 Gy/1.8 Gy fx, and Rio et al. LDR interstitial BT with 92.5% radical LC. This series sits below those on the nose, driven by the tip.
Only 9 SCC, so no histology-specific read. Cosmesis was physician-graded and the G4 dermatitis rate differs between Results (21%) and Discussion (12%).
Authors attribute nasal-tip failure to undersized three-tube molds and poor catheter bending at the tip's lower surface, and now add catheters. A deeper prescription point was not excluded as a cause.
Retrospective single-arm series, 51 lesions, one institution; no comparator vs Mohs, electrons or orthovoltage. Nasal-tip failures tied to an early three-tube applicator.
- Do multi-catheter nasal molds restore control on the nasal tip?
- Contact HDR-BT vs Mohs or electrons for cosmesis and control
- Would a deeper prescription point reduce marginal failures?
📚 Sources · 📄 1 paper
The longer read
The useful content of this series is less the headline 89% five-year control than the pattern of where and why it failed. Every relapse occurred on the nose, every relapse had been treated with the earliest three-catheter version of the wax mold, and four of the five sat on the nasal tip. Two of the five were marginal. That clustering points to a geometric problem, coverage of a highly curved surface by parallel tubes that do not bend enough, rather than an inadequate dose. The two border failures had received 54 and 57 Gy, the upper end of the schedules used, which is hard to reconcile with underdosing as the explanation. A reader planning surface mold work should take the applicator lesson more seriously than the fractionation lesson.
Against the comparators the authors themselves tabulate, the flat-surface result (16 of 16 controlled) is in line with what contact HDR series report, and the Guix experience at 60-65 Gy in 1.8 Gy fractions reached 98% at five years. The nose is where this series falls short of that benchmark, and the gap is almost entirely the tip. Excluding the tip, non-tip nasal control of 95% looks comparable to what electrons or orthovoltage would be expected to deliver, though the series offers no internal comparison and the numbers are small enough that one additional failure shifts the estimate visibly.
Several design features should temper confidence. This is a retrospective series of 51 lesions from one institution, selected for HDR because of size and location, with thickness capped at 3 mm and thicker lesions diverted to electrons. That selection removes exactly the tumors most likely to fail a 3 mm prescription, so the control rate describes a favorable subset. SCC accounts for nine lesions, too few to say anything about histology. Cosmesis was graded on a four-point physician scale with no patient-reported measure. The paper also reports the severe acute dermatitis rate inconsistently, 21% in Results and 12% in the Discussion, which matters because grade 4 skin reaction in roughly a fifth of an elderly cohort is not a trivial trade for a 48 Gy course.
What the series does settle is practical: a 4 Gy by 12 fraction contact HDR course, delivered in short outpatient sessions without anesthesia, is feasible and controls thin lesions on flat facial skin and the nasal dorsum and ala, with surgery available as salvage. What it does not settle is whether the newer multi-catheter molds fix the tip problem, whether a deeper prescription point would have, or how HDR contact BT compares head to head with Mohs or electrons for cosmesis and control. For the tip specifically, the authors' own conclusion is to use another technique, and the data support that reading.