P03.10.B A successful case of Histiocytic sarcoma

Background

Histiocytic sarcoma (HS) is an extremely rare malignant neoplasm accounting for less than 1% of all hemato-lymphoid neoplasms. Sixty percent of all cases are metastatic at presentation and the prognosis is really poor. Currently, there are limited treatment options for HS, and no standard treatment can be recommended. Surgery and/or chemotherapy are the most commonly employed treatment modalities for HS, while radiotherapy seems to be an effective option in patients with localized lesions.

Material and Methods

A 48-year-old woman admitted to our hospital for a drug-resistant neck pain. Her medical record review was relevant for hypothyroidism in replacement therapy, hystero-adnexectomy for fibromatosis (2 years ago), anxiety-depressive syndrome. A Brain and Head-and-Neck Magnetic Resonance Imaging (MRI) showed a left expansive osteolytic occipito-cervical vertebral lesion at level C1-C2, measuring 3.4cm x 2.3 cm x 2.6 cm. The mass was completely resected on July 12,2021 and pathological and immunohistochemical staining confirmed the diagnosis of HS with positive immunohistochemistry for CD163, CD4, CD68, CD14, CD45 / LCA; weak expression of S100 and focal positivity for lysozyme; Ki67 = 45%.On August 10, 2021 a 18F-FDG PET/CT imaging of the total body did not reveal any distal metastases. On August 13, 2021 a bone marrow aspirate showed no neoplastic cells. She underwent to an adjuvant chemotherapy regimen that consisted of ifosfamide administered as an infusion with bolus carboplatin, and etoposide (ICE). On August 28,2021 a concomitant radiotherapy is given, with a total dose of 45 Gy delivered in 15 fractions plus a sequential boost to 54 Gy.Results: VMAT was used to deliver a conformal RT plan. The patient tolerated the entire treatment very well, with a Grade 1 dysphagia immediately after the completion of radiotherapy, with a complete resolution about a week later. At last Brain Head-and-Neck RMN and 18F-FDG PET/CT on March 28, 2022 there is no evidence of recurrent disease.

Conclusion

The favorable outcome of our patient with combined chemotherapy and radiotherapy should promote future research to explore treatment protocols in patients with localized or favorable subtypes of HS.For patients with a good PS, young age, long life expectancy, advanced RT techniques may be used to customize safe treatment.

P03.04.B Garcin syndrome and hippocampal-sparing WBRT: successful resolution of a rare case

Background

first case of a rare Garcin syndrome resolution in a young metastatic breast cancer(BC) patient treated with a hippocampal-sparing approach.

Material and Methods

we report a case of a 49-year-old caucasian female. The medical record review was relevant for BC diagnoses in 1997, when she was 26yo; complicated by bone and liver metastasis appeared in 2008. In March 2020, she was referred to our department complaining about increasingly worsening left otalgia with initial hearing loss, left facial numbness, and homolateral decreased facial sensitivity, left increased lacrimation, and tingling tongue. Clinical presentation was suggestive for a Guillain-Alajouanine-Garcin Syndrome (Garcin Syndrome), caused by a lytic lesion in the left sphenoid wing. A contrast MRI (02/04/2020) of the brain demonstrated a lytic lesions in the left sphenoid wing, that was noted to infiltrate surrounding bone of the sphenoid sinus wall, including clivus, left pterygoid process and petrous bone; two parietal and occipital bone lesions were identified with a partial leptomeningeal involvement. According to the good PS, she underwent to a hippocampal-sparing WBRT VMAT plus a sequential boost on sphenoid lesion. PTV and OARs were delineated according to a fused planning MRI/CT image. Bilateral hippocampal contours were generated on the set according to RTOG 0933 contouring atlas. After that, a hippocampal avoidance(HA) region was created by expanding the hippocampal contours by 5 mm in all directions according to Brown et al.The PTV-HA was defined as the WB parenchyma, meninges and skull, excluding the HA-region, dose prescription 30Gy/10fx; the PTV-Boost was defined as the sphenoidal metastases, dose prescription of sequential boost was 12Gy/4fx. VMAT was used to deliver the conformal RT plan. Planning priorities that should be followed were:Hippocampus, OpticChiasm, OpticNerve_L or OpticNerve_R, Lens_L or Lens_R.

Results

The neurological symptoms improved after the end of RT with a complete resolution two months later. At the last MRI, a year and a half from the end of RT, there was no evidence of brain lesion, and no neurological symptoms were referred. These are our results of plan sum: for PTV-HA D2%=43.43 Gy, D98%=26.36 Gy, V30=94.96%; for Hippocampus D100%=8.78 Gy, Dmax=17.24 Gy; for Left OpticNerve Dmax=33.51%; for Right OpticNerve Dmax=29.25%; for OpticChiasm Dmax=35.93%.

Conclusion

To our knowledge, this is the first described case using the VMAT technique to spare the hippocampus plus a boost in a rare case of Garcin Syndrome. Prevention of neurocognitive sequelae by hippocampal avoidance has shown promise in several studies as in this case. Sequential boost demonstrated to be feasible and effective.Advanced RT techniques may be used to customize a treatment that allows preserving cognitive impairment achieving good clinical results in the long-term survival of metastatic patients.