Intensity-modulated radiation therapy for orbital lymphoma

Management of Graves' ophthalmopathy by radiotherapy: A literature review

Orbital radiotherapy for Graves' ophthalmopathy is an example of non-oncological radiotherapy. First introduced in the 1930s, this treatment has become widely used since the 1980s with several studies showing proof of both effectiveness and safety: a decrease of soft tissue involvement in 70 to 80% of patients and an improvement of ocular mobility in 30 to 80% of patients. Nowadays, it's one of the second line treatment options recognized by the European Group on Graves' orbitopathy in the management of a moderate to severe and active disease after failure of glucocorticoids. In that setting, orbital radiotherapy should be combined with glucocorticoids. To our knowledge, there are no practical recommendations on how orbital radiotherapy should be planned and conducted for Graves' ophthalmopathy. Optimal dose is not defined however the most frequent regimen consists of 20Gy in ten fractions of 2Gy, though other options may yield better results. Lastly, the use of modern technique of radiotherapy such as intensity-modulated radiation therapy may allow a better sparing of organs at risk compared to three-dimensional radiotherapy using lateral opposing fields.

Effects of radiation therapy on the meibomian glands and dry eye in patients with ocular adnexal mucosa-associated lymphoid tissue lymphoma

BACKGROUND

Radiation therapy (RT) is the treatment of choice in patients with low-grade ocular adenexal mucosa-associated lymphoid tissue lymphoma (OAML) and many of them experience post-RT dry eye with varying severity. The purpose of the present study was to investigate ocular effects of RT on meibomian glands and dry eye by directly visualizing structural changes. Secondly, we focused on the comparison of two groups of patients according to tumor location and radiation technique.

METHODS

Sixty-four eyes with OAML of conjunctiva, orbit, lacrimal gland, or lacrimal sac were grouped into conjunctival lymphoma and "orbital-type" lymphoma (i.e., orbit, lacrimal gland, and lacrimal sac). Subjects were investigated for morphological changes in meibomian glands by meiboscore grading system. Radiation technique was examined and Ocular Surface Disease Index (OSDI) questionnaire, Schirmer's test, tear film break-up time (TBUT), slit lamp examination of corneal surface and lid margin abnormality were conducted before and after RT.

RESULTS

The increase in meiboscore was statistically significant over time after RT in both groups (P < 0.001). The extent of increase in meiboscore was significantly greater in the "orbital-type" lymphoma group than in the conjunctival lymphoma group (P < 0.001). The changes in OSDI, TBUT, corneal fluorescein staining score and lid margin abnormality score after RT were significantly different across two groups (P = 0.042, 0.001, 0.035 and 0.001, respectively). Schirmer's value decreased after RT in both groups. Dry eye symptoms were most severe right after RT in both groups, but a gradual resolution was noted in most patients with conjunctival lymphoma, whereas symptoms persisted in "orbital-type" lymphoma patients. The OSDI score and corneal fluorescein staining score were positively correlated with meiboscore in "orbital-type" patients at post-RT 6 months (r = 0.43, P = 0.04; r = 0.39, P = 0.03, respectively).

CONCLUSIONS

Patients with OAML had different degrees of morphological changes in meibomian glands according to tumor location and radiation technique. "Orbital-type" lymphoma patients are more likely to experience severe injury to meibomian glands, which eventually leads to persistent dry eye. Patients with "orbital-type" lymphoma should be well informed of post-RT damage on meibomian glands and persistent dry eye.

Orbital lymphoma

Orbital lymphomas constitute 50-60% of ocular adnexal lymphomas. A total of 2211 cases of orbital lymphoma with a known subtype have been reported in the last 24 years (1994-2017). The vast majority of orbital lymphomas are of B-cell origin (97%), of which extranodal marginal zone B-cell lymphoma (EMZL) (59%) is the most common subtype, followed by diffuse large B-cell lymphoma (23%), follicular lymphoma (9%), and mantle cell lymphoma (5%). Orbital lymphoma is primarily a disease of the elderly. Gender distribution varies according to lymphoma subtype. However, extranodal marginal zone B-cell lymphoma (53%) and follicular lymphoma (75%) show a female predominance, whereas diffuse large B-cell lymphoma shows an even gender distribution. Mantle cell lymphoma has a striking male predominance of 80%. The histopathological subtype and the clinical stage of the disease are the best indicators of prognosis and patient outcome. Low-grade lymphomas such as extranodal marginal zone B-cell lymphoma and FL have a good prognosis, whereas high-grade lymphomas (diffuse large B-cell lymphoma and mantle cell lymphoma) are associated with a poor prognosis. When managing solitary low-grade lymphomas, radiotherapy is the treatment of choice. Chemotherapy, with or without radiotherapy, should be chosen for disseminated and high-grade lymphomas.

Clinical outcomes of graves' ophthalmopathy treated with intensity modulated radiation therapy

BACKGROUND

Radiation for Graves' ophthalmopathy (GO) has traditionally utilized lateral opposing fields (LOF) or three-dimensional conformal radiotherapy (3DCRT) technique. The current study was conducted to report clinical outcomes and therapeutic effects of intensity modulated radiation therapy (IMRT) in treating GO patients.

METHODS

One hundred sixteen patients with GO were treated with IMRT as initial local therapy between July 2010 and August 2013, with a median follow-up of 62 months (range 45-81 months). Radiotherapy dose was 20 Gy in 10 fractions within two to three weeks. The immediate and long-term response to IMRT was evaluated in GO severity score and in each category of symptoms. Acute and long-term complications were recorded to assess its safety.

RESULTS

Symptom severity score significantly fell from the start of treatment to 4- or 6- month post-IMRT (P < 0.01). In total, 85 patients (73.3%) experienced improvement of GO symptoms in the first half-year, and only 4 of them (4.7%) suffered recurrence of the GO symptoms during the subsequent follow-ups. Orbital pain, tearing and extraocular muscle dysfunction had the best treatment reaction to IMRT, while proptosis and blurred vision were the most refractory symptoms. Acute complications were slight and self-limited, mainly including intermittent eye redness in 9 patients (7.8%), sideburns hair loss in 19 patients (16.4%), increased milphosis or madarosis in 23 patients (19.8%) and pseudo-progression of GO symptoms in 15 patients (12.9%). For long-term complications, chronic xerophthalmias occurred in 7 patients (6.03%), cataract developed in 2 patients (1.72%), and all were well-managed by medical interventions. Radiation retinopathy and secondary malignancy was not presented in the cohort.

CONCLUSION

The study demonstrated that IMRT could serve as a viable option in treating GO patients, with a satisfactory symptom control ability, and relatively slight and acceptable post-radiotherapeutic complications.

Aqueous Deficient Dry Eye Syndrome Post Orbital Radiotherapy: A 10-Year Retrospective Study

Purpose

Despite advances in orbital radiotherapy (XRT), a significant proportion of patients develop ophthalmic complication like dry eye syndrome (DES). The study evaluates the prevalence of aqueous deficient DES (ADDE) and lacrimal gland (LG) changes through histologic evaluation and ex-vivo expansion potential postorbital XRT.

Methods

With the approval of the institutional review board, medical records of patients who underwent orbital XRT as management protocol were reviewed for evidence of ADDE using DEWS (Dry Eye Workshop) 2007 criteria (n = 51). HuLG was harvested from three of these patients who underwent subsequent orbital exenteration and used for histological studies/ex-vivo culture.

Results

ADDE was noted in 47.07% of the patients, status postorbital XRT, with a prediction of nearly 50% developing it within 0.5 to 2.9 years. ADDE severity was grade 2 (18%), grade 3 (14%), and grade 4 (17%). Other comorbidities were radiation retinopathy (33.4%), radiation-induced cataract (24.9%), and radiation keratopathy (20.8%). Multivariate and univariate analysis showed that fraction of radiation and dose of radiation/fraction were significant risk factors; male gender and young age were protective factors. The post-XRT exenterated HuLG showed near-total effacement of histoarchitecture with intra/periductal and intra/interlobular fibrosis, loss of acini, and reduced secretory activity. The potential of the LG to expand and grow in culture was impaired with loss of stem cells as compared to normal HuLG.

Conclusion

This study documents that orbital-XRT is associated with morphological and functional loss of lacrimal function in nearly 50% of the patients with a prediction of two-third developing ADDE by the end of 5 years.

Translational Relevance

The study provides objective clinical evidence for DES development due to architectural/functional damage to the LG postorbital XRT. Based on recent findings that the LG can be cultured in-vitro, with preservation of stem cells and secretory potential, it would be logical to harvest a portion of LG before radiation, and expand and transplant it to rescue the damaged gland if indicated.

Dosimetric advantage of volumetric modulated arc therapy in the treatment of intraocular cancer

Objective

The purpose of this study is to investigate the dosimetric advantages of volumetric modulated arc therapy (VMAT) in the treatment of intraocular cancer by comparing it directly with three-dimensional conformal radiotherapy (CRT) and intensity-modulated radiotherapy (IMRT).

Methods

CRT plan, 7f-IMRT plan, and one-arc VMAT plan were generated for 14 intraocular cancer patients. Dosimetric and biological quality indices for target volume and organs at risks (OARs) were evaluated and compared.

Results

The target coverage presented by V95 for CRT, IMRT and VMAT were 95.02% ± 0.67%, 95.51% ± 2.25%, and 95.92% ± 3.05%, respectively. The homogeneity index (HI) for CRT, IMRT and VMAT were 0.15 ± 0.05, 0.23 ± 0.05, and 0.23 ± 0.06, respectively. IMRT and VMAT greatly decreased the dose to ipsilateral lens compared with CRT with a D1 of 2972.66 ± 1407.12 cGy, 3317.82 ± 915.28 cGy and 4809.54 ± 524.60 cGy for IMRT, VMAT and CRT, respectively. Similar results were observed for ipsilateral eyeballs. IMRT and VMAT also spared better on brainstem, optical nerves and optical chiasm compared CRT. However, CRT achieved lower dose to the eyeballs compared with IMRT and VMAT. VMAT and IMRT showed mixed results on target coverage and OAR sparing. The average MUs and delivery time of IMRT and VMAT were 531.25 ± 81.21 vs. 400.99 ± 61.49 and 5.05 ± 0.53 vs.1.71 ± 0.69 min, respectively.

Conclusions

Although no clear distinction on PTV coverage among CRT, IMRT and VMAT plans was observed in the treatment of intraocular cancer, VMAT and IMRT achieved better homogeneity and conformity for target volume, and delivered fewer doses to ipsilateral lens and eyeballs compared with CRT. However, VMAT and IMRT increased the low dose volume to the contralateral OARs. Although VMAT and IMRT showed mixed results on target coverage and OAR sparing, VMAT decreased MU and delivery time significantly compared with IMRT. VMAT is a promising and feasible external beam radiotherapy technique in the treatment of intraocular cancer patients.

Extranodal Marginal Zone Lymphoma of Ocular Adnexa: Outcomes following Radiation Therapy

Aim

The aim of this study was to report outcomes following radiation therapy in patients with biopsy-proven extranodal marginal zone lymphoma of the ocular adnexa and uvea.

Methods

Records from a single institution were retrospectively reviewed from January 1997 to December 2015. The mean follow-up duration was 38 months (range 0-194). Radiation therapy was administered to 77 eyes (60 patients); 57 of the 77 eyes (74%) were treated with radiation only (range 20-36 Gy, median 15 fractions). Radiation cataract, radiation retinopathy, and optic neuropathy assessments were performed on all eyes treated with radiation.

Results

100% of the 47 patients treated with radiation therapy only had local control with an average dose of 26.5 Gy (median 25.2 [range 20-36] Gy; 150-200 cGy per fraction). Four patients lost 2 lines or more of vision after radiation. The most common complication of radiation therapy was cataract formation/progression in 19 eyes (25%). Radiation retinopathy was observed only in 1 patient (1%).

Conclusion

Our results confirm that radiation therapy (median 25 Gy) for extranodal marginal zone lymphoma of the ocular adnexa is associated with high local control and low risk of visually significant complications.

Volumetric Modulated Arc Therapy (VMAT) make a difference in retro-orbital irradiation treatment of patients with bilateral Graves' ophthalmopathy. Comparative analysis of dosimetric parameters from different radiation techniques

BACKGROUND

Graves' ophthalmopathy is the commonest extrathyroidal manifestation of Graves' disease. Treatment options include steroid therapy, corrective/decompressive surgery, radiation therapy or combination of these approaches.

AIM

Our purpose was to investigate if retro-orbital irradiation with Volumetric Modulated Arc Therapy (VMAT) yielded better target coverage and dose sparing to adjacent normal structures compared to 3-Dimensional Conformal Radiotherapy (3DCRT) and Lateral Opposing Conformed Fields (LOCF).

METHODS

Fourteen consecutive patients diagnosed with bilateral Graves' ophthalmopathy were prospectively recruited into this study from August 2012 until August 2014. An individual VMAT, 3DCRT and LOF plan was created for each patient. Conformity Index (CI), Homogeneity Index (HI) and other dosimetric parameters of the targets and organs-at-risk (OAR) were analyzed in all 28 orbits compared between the different techniques.

RESULTS

CI generated by VMAT was superior to that produced by 3DCRT(p < .001) and LOF (p < .001). As expected, 3DCRT was also superior to LOF (p = .007). Regarding the OARs sparing dose (lens, globes, retina and lacrimal glands), VMAT showed a significant benefit when compared with 3DCRT and LOCF, with no differences between the two latter techniques.

CONCLUSIONS

VMAT should be preferred over 3DCRT and LOF for bilateral Graves' ophthalmopathy treatment.

[Malignant tumours of the eye: Epidemiology, diagnostic methods and radiotherapy]

Malignant tumours of the eye are not common, barely representing 1 % of all cancers. This article aims to summarise, for each of the main eye malignant diseases, aspects of epidemiology, diagnostic methods and treatments, with a focus on radiation therapy techniques. The studied tumours are: eye metastasis, intraocular and ocular adnexal lymphomas, uveal melanomas, malignant tumours of the conjunctive, of the lids, and retinoblastomas. The last chapter outlines ocular complications of radiation therapy and their management.

Orbital carcinomas treated with adjuvant intensity-modulated radiation therapy

BACKGROUND

The purpose of this study was to assess outcomes of patients with orbital carcinomas treated with orbital exenteration and intensity-modulated radiation therapy (IMRT).

METHODS

Twenty-nine patients were treated with orbital exenteration and postoperative IMRT between 2002 through 2011; their medical records were retrospectively reviewed.

RESULTS

Adenoid cystic carcinoma represented the most common histology (41%) followed by squamous cell carcinoma (21%). Perineural invasion (PNI) was identified in 22 patients (76%). The median radiation dose was 60 Gy (range, 60-70). Seven patients (24%) received neck radiation. The median follow-up was 43 months (range, 5-102 months). Five-year local control, overall survival (OS), and disease-free survival rates were 83%, 60%, and 55%, respectively. PNI (p = .01) and especially involvement of a named nerve (p = .001) significantly correlated with worse OS.

CONCLUSION

Favorable disease control rates for orbital carcinomas are achievable with IMRT after orbital exenteration even for patients with advanced disease. Toxicity for the contralateral eye was minimal. © 2015 Wiley Periodicals, Inc. Head Neck 38: E580-E587, 2016.

Comparative analysis of dosimetric parameters of three different radiation techniques for patients with Graves' ophthalmopathy treated with retro-orbital irradiation

Background

We would like to investigate the if IMRT produced better target coverage and dose sparing to adjacent normal structures as compared with 3-dimensional conformal radiotherapy (3DCRT) and lateral opposing fields (LOF) for patients with Graves’ ophthalmopathy treated with retro-orbital irradiation.

Methods

Ten consecutive patients diagnosed with Graves’ ophthalmopathy were prospectively recruited into this study. An individual IMRT, 3DCRT and LOF plan was created for each patient. Conformity index (CI), homogeneity index (HI) and other dosimetric parameters of the targets and organs-at-risk (OAR) generated by IMRT were compared with the other two techniques.

Results

Mann–Whitney U test demonstrated that CI generated by IMRT was superior to that produced by 3DCRT and LOF (p=0.005 for both respectively). Similarly HI with IMRT was proven better than 3DCRT (p=0.007) and LOF (p=0.005). IMRT gave rise to better dose sparing to some OARs including globes, lenses and optic nerves as compared with 3DCRT but not with LOF.

Conclusions

IMRT, as compared with 3DCRT and LOF, was found to have a better target coverage, conformity and homogeneity and dose sparing to some surrounding structures, despite a slight increase but clinically negligible dose to other structures. Dosimetrically it might be a preferred treatment technique and a longer follow up is warranted to establish its role in routine clinical use.

Arterial wall dosimetry for non-Hodgkin lymphoma patients treated with radioimmunotherapy

Tumors in non-Hodgkin lymphoma (NHL) patients are often proximal to the major blood vessels in the abdomen or neck. In external-beam radiotherapy, these tumors present a challenge because imaging resolution prevents the beam from being targeted to the tumor lesion without also irradiating the artery wall. This problem has led to potentially life-threatening delayed toxicity. Because radioimmunotherapy has resulted in long-term survival of NHL patients, we investigated whether the absorbed dose (AD) to the artery wall in radioimmunotherapy of NHL is of potential concern for delayed toxicity. SPECT resolution is not sufficient to enable dosimetric analysis of anatomic features of the thickness of the aortic wall. Therefore, we present a model of aortic wall toxicity based on data from 4 patients treated with (131)I-tositumomab.

METHODS

Four NHL patients with periaortic tumors were administered pretherapeutic (131)I-tositumomab. Abdominal SPECT and whole-body planar images were obtained at 48, 72, and 144 h after tracer administration. Blood-pool activity concentrations were obtained from regions of interest drawn on the heart on the planar images. Tumor and blood activity concentrations, scaled to therapeutic administered activities-both standard and myeloablative-were input into a geometry and tracking model (GEANT, version 4) of the aorta. The simulated energy deposited in the arterial walls was collected and fitted, and the AD and biologic effective dose values to the aortic wall and tumors were obtained for standard therapeutic and hypothetical myeloablative administered activities.

RESULTS

Arterial wall ADs from standard therapy were lower (0.6-3.7 Gy) than those typical from external-beam therapy, as were the tumor ADs (1.4-10.5 Gy). The ratios of tumor AD to arterial wall AD were greater for radioimmunotherapy by a factor of 1.9-4.0. For myeloablative therapy, artery wall ADs were in general less than those typical for external-beam therapy (9.4-11.4 Gy for 3 of 4 patients) but comparable for 1 patient (32.6 Gy).

CONCLUSION

Blood vessel radiation dose can be estimated using the software package 3D-RD combined with GEANT modeling. The dosimetry analysis suggested that arterial wall toxicity is highly unlikely in standard dose radioimmunotherapy but should be considered a potential concern and limiting factor in myeloablative therapy.