Transpupillary thermotherapy versus plaque radiotherapy for suspected choroidal melanomas

To examine the outcomes and complications of transpupillary thermotherapy for treatment of small choroidal melanomas.

Retrospective case-matched comparative study and retrospective observational study.

The case-matched study consisted of 36 patients treated with either transpupillary thermotherapy or plaque radiotherapy (18 patients per group). The observational study consisted of 21 patients treated with transpupillary thermotherapy alone (primary transpupillary thermotherapy) and 9 patients treated with transpupillary thermotherapy plus plaque radiotherapy (adjuvant transpupillary thermotherapy).

Visual acuity, local tumor control, and metastasis.

The case-matched groups did not differ significantly with respect to age, gender, initial visual acuity, tumor location, or length of follow-up (mean, 33 months for transpupillary thermotherapy vs. 40 months for plaque radiotherapy). There was no significant difference in final visual acuity (P = 0.810) or postoperative visual acuity change (P = 0.919) between the 2 groups. In the observational study, the mean follow-up was 32 months (range, 4-58 months). Indications for primary transpupillary thermotherapy included documented growth (10 patients) and the presence of >/=3 risk factors for growth (11 patients). Retinal complications occurred in 16 patients (76%). The mean posttreatment visual acuity change was minus 2 lines (range, minus 9 to plus 7 lines). Local failure occurred in 6 patients (29%). Local failure was associated with an increased number of transpupillary thermotherapy spots per session (P = 0.023) and decreased tumor pigmentation (P = 0.001). Indications for adjuvant transpupillary thermotherapy included tumor radioresistance (6 patients) and the presence of risk factors for local failure (3 patients). All 9 tumors that received adjuvant transpupillary thermotherapy regressed rapidly, with no local failures. The mean postoperative visual acuity change was -1.9 lines (range, -9 to +5 lines). No patient in either study developed metastasis.

The recent interest in transpupillary thermotherapy as primary therapy for choroidal melanoma is based largely on the assumption that transpupillary thermotherapy may provide better visual outcomes than plaque radiotherapy. However, this study found no significant difference in visual outcomes between transpupillary thermotherapy and plaque radiotherapy. Further, the local failure rate with transpupillary thermotherapy was substantially higher than with plaque radiotherapy. The most promising role for transpupillary thermotherapy seems to be as an adjunct to plaque radiotherapy. The appropriate indications for transpupillary thermotherapy in the management of choroidal melanoma need to be re-evaluated.