Stereotactic radiosurgery as the initial management option for small-volume hypothalamic hamartomas with intractable epilepsy: a 35-year institutional experience and systematic review

OBJECTIVE

Young patients with hypothalamic hamartomas (HHs) often present with intractable epilepsy. Currently there are no established management guidelines for HH. The authors retrospectively reviewed their single-institution experience to delineate the role of stereotactic radiosurgery (SRS).

METHODS

Seven patients with HHs (4 females; median age 13.7 years, range 2.5-25 years) with no prior resection underwent SRS between 1987 and 2022. The clinical history, epilepsy profile, radiographic findings, and neurological outcomes were characterized. HH topographical types were classified according to the Régis classification. Outcome measures included Engel seizure classification, HH response, and the need for additional surgical interventions.

RESULTS

All patients had Engel class IV epilepsy. A Leksell Gamma Knife was used to deliver a median margin dose of 18 Gy (range 16-20 Gy) to a median hamartoma volume of 0.37 cm3 (range 0.20-0.89 cm3). Seizure reduction was confirmed in 6 patients, and 2 patients had regression of their hamartoma. Two patients underwent resection and/or laser interstitial thermal therapy after SRS. At follow-up, 1 patient was seizure free, 4 patients achieved Engel class II, 1 patient had Engel class III, and 1 patient had Engel class IV seizure outcomes.

CONCLUSIONS

SRS as the initial management option for HH was associated with a low risk of adverse effects. In this institutional series reviewing small-volume HHs treated with SRS, no adverse radiation effect was detected, and the majority of patients experienced seizure reduction. SRS should be considered as the first-line treatment for seizure control in patients with small-volume HHs.

Interstitial radiosurgery in the treatment of gelastic epilepsy due to hypothalamic hamartomas

The authors evaluated a new stereotactic radiosurgical approach in seven patients with gelastic epilepsy due to hypothalamic hamartomas. Stereotactic implantation of 125I-seeds into the hamartoma was feasible in six patients. At follow-up at least 1 year after interstitial radiotherapy, two patients had become seizure-free within 2 months, and two others had only persisting auras. There were no major perioperative or postoperative side effects.

Porokeratotic eccrine ostial and dermal duct naevus with dermatomal trunk involvement: literature review and report on the efficacy of laser treatment

Porokeratotic eccrine ostial and dermal duct naevus (PEODDN) is a rare, benign hamartomatous malformation involving the eccrine sweat duct. The existence of filiform keratinous plugs that represent cornoid lamellae overlying dilated infundibula of eccrine ducts is a distinctive feature and the presence of associated abnormal dermal ducts is frequent. We report a patient with PEODDN who exhibited lesions on the left side of her chest. Cases of PEODDN reported in the literature are reviewed. Our experience in treating this patient with ultrapulsed carbon dioxide laser is also presented.

Ignition potential of the 585-nm pulsed-dye laser. Review of the literature and safety recommendations

BACKGROUND

The 585-nm pulsed-dye laser is the treatment of choice for many port-wine stains. The risk of accidental flash fires occurring with the pulsed-dye laser is considered minimal. Recently, however, there have been several reports of unwanted ignitions. These cases all share two features: 1) oxygen delivery by face mask, and 2) the ignition of a hair-bearing surface.

OBJECTIVE

We report a case of a laser-induced fire that occurred on a non-hair-bearing surface in a patient who was receiving oxygen by nasal cannula. The mechanisms, risk factors, and guidelines for the prevention of pulsed-dye laser-induced fires are presented.

METHODS

We reviewed the literature regarding the safety of pulsed-dye laser use.

RESULTS

Pulsed-dye laser-induced fires can occur on non-hair-bearing regions and in patients receiving oxygen by nasal cannula.

CONCLUSION

Precautions should be taken to prevent pulsed-dye laser fires regardless of treated region or method of oxygen delivery.

Mathematical modelling of dynamic cooling and pre-heating, used to increase the depth of selective damage to blood vessels in laser treatment of port wine stains

Based on the assumption that the maximum irradiance allowed during laser treatment of port wine stains is limited by the temperature rise at the dermoepidermal junction, we theoretically investigated how much the irradiance could be increased by dynamically cooling the skin surface. The heat condution equation was solved numerically in cylindrical coordinates using a skin model composed of four layers. The laser-light absorption was calculated using Monte Carlo simulations. The transient thermal behaviour of the skin was modelled when cooling with water at a temperature of 0 degrees C and with liquid nitrogen at a temperature of -196 degrees C. With cooling, an increase in the maximum irradiance by a factor of 2.3-3.6 was theoretically permitted depending on the irradiation time, wavelength and mode of cooling. The corresponding increase in vessel selective damage depth was predicted to be 0.4-0.5 mm. A new concept for increasing the depth of vessel selective damage is introduced where the initial temperature profile of the skin is reshaped by using not only surface cooling but also laser irradiation. By pre-irradiating the skin with near-infrared light without selective absorption by the tissue chromophores in conjunction with surface cooling, a maximum temperature at a depth of 1 mm from the dermoepidermal junction was theoretically achieved. A subsequent 0.1 s pulse from a frequency doubled Nd:YAG laser is theoretically shown to selectively destroy vessels up to a depth of 0.8 mm from the dermoepidermal junction. By pre-heating at 1064 nm and treating at 532 nm in conjunction with surface cooling, the theoretical results indicate that the Nd:YAG laser can compete in effectiveness with the flashlamp-pumped dye laser in the treatment of port wine stains.

Pulsed dye laser treatment of port-wine stains. A patient questionnaire

BACKGROUND

The flashlamp-pumped pulsed dye laser is recognized as the treatment of choice for port-wine stains. Most studies assessing its effectiveness are based on clinical reviews by the treating physician. Each patient's assessment of treatment outcome is also important.

OBJECTIVE

To assess the patients' attitudes toward laser treatment, satisfaction with treatment outcome, and reasons for withdrawal from treatment.

METHODS

A questionnaire was distributed to 186 patients with port-wine stains treated with the flashlamp-pumped pulsed dye laser. Of the 186 patients, 131 had completed treatment and 55 were having ongoing treatment or had withdrawn from treatment. Replies were received from 164 patients, a response rate of 88%.

RESULTS

Most patients expressed satisfaction with the present appearance of their treated port-wine stains. The majority of any adverse effects experienced were transient. Over 90% of patients would recommend treatment to other people with port-wine stains.

CONCLUSION

The flashlamp-pumped pulsed dye laser improves the appearance of port-wine stains, and is regarded favorably by patients. Patients' assessments of treatment outcomes correlate well with clinical results obtained.

A new optimal wavelength for treatment of port wine stains?

In this study we investigate light penetration into skin in order to define the optimal wavelength for the treatment of port wine stains. A two-layer model (epidermis and dermis) is applied with a cylindric tube representing the ectatic blood vessel. Light propagation is calculated by the Monte Carlo method. Values for the optical properties of the skin were not only taken from the literature, but also derived from measurements of the spatially resolved reflectance on the human forearm applying a multilayer model. Using the new values, the maximal depth of selective vascular injury better fits experimental and clinical observations, compared to the values in literature. In addition, the optimal wavelength for treatment of port wine stains is shifted to longer wavelengths.

A two-year review of pain control during laser therapy using the flashlamp pulsed dye laser

Laser therapy is now accepted as the treatment of choice for port wine stains. Patient reaction to laser light exposure and methods used to control pain during 1357 treatment sessions for 350 medium to large port wine stains using the SPTL-1 laser (Candela Laser Corporation) are reported. In the majority of cases (86%) it was necessary to use either general anaesthesia or some other form of local pain control.

Treatment of port-wine stains with the 585-nm flashlamp-pulsed tunable dye laser: a study of 74 patients

Over 20 months, we have treated 74 patients (59 children less than 12 years of age) with port-wine stains (PWS) using a 585-nm flashlamp-pulsed dye laser (SPTL-1, Candela Corp., Wayland, Mass., USA) after topical anesthesia with Emla cream. A 5-point reference color scale was used to evaluate the results. 45 patients had at least one treatment on the entire surface of the lesion. A mean of 88 impacts per session was delivered. There was a significant decrease in color in around two thirds of the cases after one complete treatment with a gradual tendency to improvement after subsequent treatments. Younger age at the beginning of treatment was not found to be predictive of a better outcome after the first treatment. In around one third of the cases, positive test site treatment was not correlated with significant improvement after one treatment. Lesions situated on the limbs were less responsive than those on the head and neck. Except for problems due to absence of general anesthesia in young children enduring repeated stressful and sometimes painful procedures, the overall impression is that early treatment of PWS is possible with very limited risks of scarring using this technique.

Clinical experience with the tunable pulsed-dye laser (585 nm) in the treatment of capillary vascular malformations

A retrospective review of 134 patients who received laser therapy with the pulsed-dye laser at the 585-nm wavelength for capillary vascular malformations was conducted. These patients were treated over a 5-year period with a minimum follow-up of 2 years. Ninety-five patients were available for evaluation of results. Thirty-nine were lost to follow-up. Each birthmark was described before and after treatment under a classification system developed by the authors. Results were reported by classification, age, anatomic location, and race. Excellent or good results were obtained in the majority of patients in all age groups and regardless of the color of the birthmark. All anatomic areas and all ethnic groups responded to treatment with varying degrees of success. A range of up to eight treatments was required to achieve resolution. Scarring was an infrequent complication (1.1 percent) of treatment. Hypopigmentation was seen in 3.2 percent of treated patients. The pulsed-dye laser (585 nm) offers promise to patients of all ages and hope to those who previously were not candidates for laser therapy.

"Rubral" tremor following radiation of a pineal region vascular hamartoma

Tumours of the pineal region have historically been difficult to remove safely. Only recently have large series of successful pineal area operations been reported, and there are many advocates for surgical reticence with these tumours. We report a case of a 20-year-ol women whose pineal region tumour was irradiated, whereupon a unilateral low-frequency resting and intention tremor developed. Following resection of the lesion, a vascular hamartoma, the tremor virtually disappeared. We believe the tremor was secondary to radiation induced tumour shrinkage and distortion of the mesencephalon. This case is demonstration of the importance of exploration and histological verification of pineal region tumours.

Remission of giant lymph node hyperplasia with anemia after radiotherapy

We have described a 51-year-old patient with unresectable mesenteric giant lymph node hyperplasia of the plasma cell type, severe systemic manifestations, and profound anemia. Supression of erythropoiesis may have been related to the presence of a circulating erythropoietic inhibitor produced by the lymphoid tumor. Markedly elevated titers to Epstein-Barr virus capsid antigen suggest that this virus may be important in the etiology of the abnormal lymphoid proliferation. The marked clinical response and decrease in the size of the tumor following irradiation suggests that radiation therapy may be an alternative form of treatment for similar patients with unresectable lesions.

Astrocytic hamartoma of the retina not associated with tuberous sclerosis

A 6-year-old boy had a peripapillary lesion diagnosed as retinal astrocytic hamartoma, which was not associated with tuberous sclerosis, neurofibromatosis, or intraocular extension of a glioma. The patient was observed for nine years, during which time the lesion grew significantly. Because of this growth and the evidence of proximal optic nerve involvement on computed tomography, radiation therapy was administered with a resultant marked reduction in visual acuity. The eye was subsequently enucleated. The enucleated eye was studied by both light and transmission electron microscopy. The specimen had a retinal astrocytic hamartoma with sparse vascularization and only superficial optic nerve involvement. Additionally, it revealed optic nerve drusen in varying stages of development, significant accumulations of subretinal macrophages, and an almost total loss of retinal outer segments with the preservation of the retinal pigment epithelium.