Tumor load rather than contrast enhancement is associated with the visual function of children and adolescents with optic pathway glioma - a retrospective Magnetic Resonance Imaging study

Pediatric orbital lesions: neoplastic extraocular soft-tissue lesions

Pediatric neoplastic extraocular soft-tissue lesions in the orbit are uncommon. Early multimodality imaging work-up and recognition of the key imaging features of these lesions allow narrowing of the differential diagnoses in order to direct timely management. In this paper, the authors present a multimodality approach to the imaging work-up of these lesions and highlight the use of ocular ultrasound as a first imaging modality where appropriate. We will discuss vascular neoplasms (congenital hemangioma, infantile hemangioma), optic nerve lesions (meningioma, optic nerve glioma), and other neoplastic lesions (plexiform neurofibroma, teratoma, chloroma, rhabdomyosarcoma, infantile fibrosarcoma, schwannoma).

Treatment evaluation by volumetric segmentation in pediatric optic pathway glioma: evaluation of the effect of bevacizumab on intra-tumor components

PURPOSE

Progressive pediatric optic pathway gliomas (OPGs) are treated by diverse systemic antitumor modalities. Refined insights on the course of intra-tumoral components are limited.

METHODS

We performed an exploratory study on the longitudinal volumetric course of different (intra-)tumor components by manual segmentation of MRI at the start and after 3, 6 and 12 months of bevacizumab (BVZ) treatment.

RESULTS

Thirty-one patients were treated with BVZ (median 12 months, range: 2-39 months). During treatment the total tumor volume decreased with median 19.9% (range: - 62.3 to + 29.7%; n = 30) within the first 3 months, decreased 19.0% (range: - 68.8 to + 96.1%; n = 28) between start and 6 months and 27.2% (range: -73.4 to + 36.0%; n = 21) between start and 12 months. Intra-tumoral cysts were present in 12 OPGs, all showed a decrease of volume during treatment. The relative contrast enhanced volume of NF1 associated OPG (n = 11) showed an significant reduction compared to OPG with a KIAA1549-BRAF fusion (p < 0.01). Three OPGs progressed during treatment, but were not preceded by an increase of relative contrast enhancement.

CONCLUSION

Treatment with BVZ of progressive pediatric OPGs leads to a decrease of both total tumor volume and cystic volume for the majority of OPGs with emphasis on the first three months. NF1 and KIAA1549-BRAF fusion related OPGs showed a different (early) treatment effect regarding the tumor enhancing component on MRI, which did not correlate with tumor volume changes. Future research is necessary to further evaluate these findings and its relevance to clinical outcome parameters.

The impact of changes in gadolinium-enhancement on disease progression in children with neurofibromatosis type 1-associated optic pathway glioma: a retrospective analysis

PURPOSE

There has been limited investigation of imaging features associated with visual acuity (VA) decline and initiation of treatment for patients with neurofibromatosis type 1 (NF1) and optic pathway glioma (OPG).

METHODS

To evaluate the association of increased gadolinium enhancement with decline in VA, initiation of chemotherapy, and tumor growth, we performed a retrospective cohort study of children diagnosed with NF1-OPG between January 2006 to June 2016. Two cohorts were defined: a new diagnosis and a longitudinal cohort. Outcomes were examined at 1 and 2 years from initial diagnosis, and 1 and 2 years from initial increase in enhancement in the longitudinal cohort.

RESULTS

Eighty patients were eligible; all 80 contributed to the new diagnosis cohort and 73 to the longitudinal cohort. Fifty-six patients (70%) demonstrated enhancing NF1-OPG at diagnosis. 39% of patients in the new diagnosis cohort and 45% of those in the longitudinal cohort developed increased enhancement during the study period. There was no significant association between increases in enhancement and VA decline in the newly diagnosed or longitudinal cohorts, as well as with initiation of treatment in the longitudinal cohort. Although there was an association of enhancement increase with treatment in the new diagnosis cohort, this association was not maintained when stratified by concurrent change in tumor size.

CONCLUSION

Increased gadolinium-enhancement independent of a concurrent increase in tumor size on MRI should not be used as a marker of NF1-OPG progression and does not appear to be associated with visual decline or initiation of chemotherapy.

Supratentorial Pediatric Midline Tumors and Tumor-like Lesions: Clinical Spectrum, Natural History and Treatment Options

Childhood Central Nervous System tumors account for 25% of all pediatric tumors. Large availability and broadening of indications to imaging has made incidental findings more common. Among these, midline lesions have different clinical relevance depending on their intrinsic pattern of behaviour and on their specific location. In this narrative review we describe the natural history and treatment options of midline lesions in children.

Surgical Management of Pre-Chiasmatic Intraorbital Optic Nerve Gliomas in Children after Loss of Visual Function—Resection from Bulbus to Chiasm

Optic pathway gliomas in children carry significant morbidity and therapeutic challenges. For the subgroup of pre-chiasmatic gliomas, intraorbital and intradural resection is a curative option after blindness. We present a two-center cohort using different surgical approaches. A retrospective analysis was performed, including 10 children. Mean age at surgery was 6.8 years. Interval between diagnosis and surgery was 1–74 (mean 24 ± 5.5, median 10) months. Indications for surgery were exophthalmos, pain, tumor progression, or a combination. Eight patients underwent an extradural trans-orbital-roof approach to resect the intra-orbital tumor, including the optic canal part plus intradural pre-chiasmatic resection. Gross total resection was achieved in 7/8, and none had a recurrence. One residual behind the bulbus showed progression, treated by chemotherapy. In two patients, a combined supra-orbital mini-craniotomy plus orbital frame osteotomy was used for intraorbital tumor resection + intradural pre-chiasmatic dissection. In these two patients, remnants of the optic nerve within the optic canal remained stable. No patient had a chiasmatic functional affection nor permanent oculomotor deficits. In selected patients, a surgical resection from bulb to chiasm ± removal of optic canal tumor was safe without long-term sequela and with an excellent cosmetic result. Surgery normalizes exophthalmos and provides an effective tumor control.