Corneal complications after orbital radiotherapy for primary epithelial malignancies of the lacrimal gland

Ocular, Orbital, and Adnexal Toxicity With High-dose Volumetric Modulated Arc Radiation Therapy for Orbital Malignancies

PURPOSE

Conventional modalities of external-beam radiation therapy (EBRT) are associated with high incidences of severe vision-threatening ocular and orbital toxicities when used to treat orbital malignancies. We investigate toxicities associated with high-dose volumetric modulated arc therapy (VMAT), a commonly used contemporary treatment modality for these tumors.

METHODS

Retrospective analysis of malignant orbital tumors managed with adjuvant high-dose VMAT preceded by globe-salvaging surgical therapy (GST) or exenteration. Dosimetric quantitation of target volumes and critical structures was performed. Incidence and severity of ocular, orbital, and adnexal toxicities were evaluated and assessed with regard to conventional EBRT toxicities for orbital malignancies described in the literature.

RESULTS

Eighty-four subjects (mean age = 65.9 ± 9.7 years) were included (N = 48 and N = 36 in GST and exenteration subgroups, respectively). Mean dose was 64.8 ± 2.1 Gy to the planning target volume. Dosing to critical structures typically did not surpass known tissue tolerance limits. Median follow up was 18.3 months. Visual acuity in the GST subgroup was not significantly different after VMAT (0.25 ± 0.06) compared with baseline (0.23 ± 0.02; P = 0.302). Whereas severe toxicities reported by major systematic analyses in the literature with older EBRT modalities were relatively common-for example, retinopathy (16-40%), optic neuropathy (16%), and corneal perforation (13%)-toxicities with VMAT were typically mild and less common. The most common toxicities with VMAT were mild dry eye (81.3%; 39/48), cataract (21.1%; 8/38 phakic eyes), and periocular dermatitis (15.5%; 13/84). Vision-threatening toxicities, including severe corneal pathologies, retinopathy, or optic neuropathy, were rare. There were no contralateral ocular or adnexal toxicities.

CONCLUSIONS

High-dose VMAT for orbital malignancies demonstrated low incidence and severity of eye-related toxicity, in contradistinction to adverse events reported from conventional forms of radiotherapy.

Organs at risk radiation dose constraints

Dose constraints are essential for performing dosimetry, especially for intensity modulation and for radiotherapy under stereotaxic conditions. We present the update of the recommendations of the French society of oncological radiotherapy for the use of these doses in classical current practice but also for reirradiation.

Clinical Spectrum and Outcomes of Ocular and Periocular Complications following External-Beam Radiotherapy for Inoperable Malignant Maxillary Sinus Tumors

Purpose

To highlight the clinical spectrum, management, and outcomes of ocular/periocular complications following high-dose external-beam radiotherapy (EBRT) for inoperable malignant maxillary sinus-involving tumors (MMST).

Methods

A retrospective, interventional case series. All patients who were diagnosed with inoperable MMST (with orbital involvement) and treated with high-dose fractionated EBRT (65 Gy in 30 fractions) at James Cook University Hospital, UK, were included.

Results

Seven patients with advanced MMST (T4aN0M0-T4bN2cM0) were included and were followed up for 23.8 ± 10.2 months. Severe lid margin disease, dry eye, and neurotrophic keratopathy were universally observed. Other complications included cicatricial conjunctivitis (71%), corneal perforation (57%), limbal stem cell deficiency (LSCD; 43%), glaucoma (29%), and superimposed candida keratitis (14%). Amniotic membrane transplant (AMT; 71%), tarsorrhaphy (43%), tectonic keratoplasty (29%), and evisceration (14%) were warranted. Intact corneal epithelium was observed in all patients and good corrected-distance visual acuity (≥20/60) was observed in 3 (43%) patients at final follow-up.

Conclusion

High-dose EBRT for inoperable MMST can lead to a wide array of severe ocular/periocular complications. AMT serves as a potentially useful treatment modality to restore the ocular surface integrity after severe radiation keratopathy. We advocate active monitoring for any evolving ophthalmic complications during and after EBRT to enable timely intervention.

Cranio-orbital Resection Does Not Appear to Improve Survival of Patients With Lacrimal Gland Carcinoma

PURPOSE

To ascertain long-term outcome of treatment for primary epithelial malignancies of the lacrimal gland and compare outcomes after cranio-orbital resection or after macroscopic tumor resection with radiotherapy.

METHODS

Comparative case series of 79 patients (49 male; 62%) treated for primary epithelial malignancies of the lacrimal gland at Moorfields Eye Hospital between 1972 and 2014. Patients were identified from clinical and pathological databases and, where available, the clinical, pathological, and imaging records reviewed. The primary outcome measures were overall survival after diagnosis, disease-free survival, and final visual acuity for patients having cranio-orbital resection (exenteration plus local bone removal), compared with macroscopic tumor resection plus radiotherapy.

RESULTS

The mean age at presentation was 48 years (median: 50 years; range: 13-84 years), with 53 (67%) having adenoid cystic carcinoma, 15 (19%), primary adenocarcinoma, and 11 (14%) carcinoma ex-pleomorphic adenoma (malignant mixed tumor). The overall survival probability of the cohort (79 patients) was 0.59 at 5 years and 0.52 at 10 years, with 36/79 (46%) patients suffering tumor-related deaths; 14 patients died from other causes, and 4 patients were lost to follow up after the minimum follow-up period. The probability of disease-free survival at 5 years for patients with adenoid cystic carcinoma, adenocarcinoma, and malignant mixed tumor was 0.52, 0.4, and 0.64, respectively, with the comparable figures at 10 years being 0.44, 0.40, and 0.64. Most importantly, the 9 patients undergoing cranio-orbital resection and the 44 having solely macroscopic tumor resection plus radiotherapy had similar overall survival (p = 0.59) and disease-free survival (p = 0.89). Subgroup analysis of the 2 treatment modalities for patients with adenoid cystic carcinoma (8 cranio-orbital resection and 32 debulking and radiotherapy) demonstrated similar results for disease-free survival (p = 0.87). Likewise, there were no significant differences between rates of recurrences between the 2 different treatments. For the 50 patients who had eye-preserving surgery and long-term visual acuity data, the final acuity was better or equal to 0.6 logMAR (6/24 Snellen) in 25 (50%).

DISCUSSION

There is no difference in either survival or tumor recurrence for lacrimal gland carcinoma treated with cranio-orbital resection, or eye-preserving tumor excision and radiotherapy. The authors, therefore, continue to advocate local resection and radiotherapy for almost all patients with primary epithelial malignancies of the lacrimal gland-this treatment having lower morbidity, causing less disfigurement, and, importantly, preserving useful vision in most patients.

Clinical management and outcomes of lacrimal sac squamous cell carcinoma

BACKGROUND

To investigate the management and outcomes of patients with lacrimal sac squamous cell carcinoma (SCC).

METHODS

This retrospective study examined 69 lacrimal sac SCC cases treated at our hospital between 1992 and 2017. The potential risk factors for prognosis, a new staging method, treatment outcomes, and complications were investigated.

RESULTS

The 5-year overall survival (OS) and progression-free survival (PFS) were 87.6 ± 4.8% and 76.3 ± 6.4%, respectively. Positive lymph node was associated with worse OS and PFS. We divided lacrimal sac SCC into four clinical stages, with significant differences in OS (P = .026) and PFS (P = .042) among each stage. Definitive radiotherapy was equivalent to surgery plus radiotherapy in 26.1% (18/69) of cases, and the incidence of complications was not higher.

CONCLUSIONS

Lymph node status was a key factor in determining outcomes. Our staging method could effectively classify tumor stage and predict prognosis, which can contribute to optimizing treatment regimes. Radiotherapy played an important role in treatment.

Radiation dose constraints for organs at risk in neuro-oncology; the European Particle Therapy Network consensus

PURPOSE

For unbiased comparison of different radiation modalities and techniques, consensus on delineation of radiation sensitive organs at risk (OARs) and on their dose constraints is warranted. Following the publication of a digital, online atlas for OAR delineation in neuro-oncology by the same group, we assessed the brain OAR-dose constraints in a follow-up study.

METHODS

We performed a comprehensive search to identify the current papers on OAR dose constraints for normofractionated photon and particle therapy in PubMed, Ovid Medline, Cochrane Library, Embase and Web of Science. Moreover, the included articles' reference lists were cross-checked for potential studies that met the inclusion criteria. Consensus was reached among 20 radiation oncology experts in the field of neuro-oncology.

RESULTS

For the OARs published in the neuro-oncology literature, we summarized the available literature and recommended dose constraints associated with certain levels of normal tissue complication probability (NTCP) according to the recent ICRU recommendations. For those OARs with lacking or insufficient NTCP data, a proposal for effective and efficient data collection is given.

CONCLUSION

The use of the European Particle Therapy Network-consensus OAR dose constraints summarized in this article is recommended for the model-based approach comparing photon and proton beam irradiation as well as for prospective clinical trials including novel radiation techniques and/or modalities.