MET-4 Clinical investigation of the cases recurred as dissemination after postoperative local irradiation for metastatic brain tumors

Last year, the authors examined the outcome of the patients with metastatic brain tumor (MBT)treated by whole-brain irradiation (WBRT)or local irradiation (LRT)after surgery. As a result, it was shown that the overall survival (OS) was same but the recurrence pattern was different. Furthermore, it was shown that there were some cases with disseminated recurrence in the LRT group. One year has passed, cases showing disseminated recurrence after LRT were examined. The subjects were 28 patients for whom LRT was selected as post-surgical irradiation since December 2017, with an average age of 66.2 years and a male-female ratio of 19: 9. Non-small cell lung cancer was the most in 17 cases. During the observation period, recurrence was observed in 12 cases, new outbreaks at other sites in 8 cases, disseminated recurrence in 4 cases, and no local recurrence. There was no clear difference in kinds of carcinoma and removal fashion between disseminated recurrence cases and other cases. Disseminated recurrence occurred between 3–10 months after surgery, 2 presented with headache, 1 with convulsions, 1 confirmed during follow-up of images, and all underwent WBRT. The lesions shrank after irradiation, but they were easy to re-grow, and the prognosis was poor. On the other hand, 10 cases died in 24 cases other than disseminated recurrence, but all cases died of primary cancer. Although LRT after surgery is non-inferior to WBRT in terms of OS and has the advantage of maintaining cognitive function, this study shows that there is a considerable risk of disseminated recurrence regardless of the removal fashion or kinds of carcinoma. It was also shown that prognosis after disseminated recurrence was poor. It is desirable to select postoperative irradiation after explaining the recurrence pattern, and when LRT is adopted, it is necessary to consider setting a short observation interval immediately after irradiation.

Brainstem intraparenchymal schwannoma with genetic analysis: a case report and literature review

Background Schwannomas are neoplasms that typically arise from the myelin sheath of peripheral nerves and rarely originate within the brain parenchyma. Some case reports present schwannomas arising from the brainstem, but regrowth of the tumor and the efficacy of postoperative irradiation have not been examined. In addition, the genetic background of schwannomas arising from the brainstem has not been investigated. Case presentation A 21-year-old male presented with diplopia, dysphagia, and left-sided hemiparesis, dysesthesia, and ataxia. Intracranial imaging showed a heterogeneous mass with a cystic lesion in the pontomedullary junction. Since the tumor caused obstructive hydrocephalus, the patient underwent subtotal tumor resection. A histopathologic evaluation aided a diagnosis of brainstem intraparenchymal schwannoma. Gradual postoperative mass regrowth was recognized. Three-dimensional conformal radiotherapy was performed on the residual mass and surgical cavity. No tumor regrowth was observed 4 years after surgery. To investigate the genetic background of the tumor, target sequences for 36 genes, including NF2, SMARCB1, and LZTR1, and microsatellite analysis for loss of 22q did not show any somatic variants or 22q loss. Conclusions We suggest that brainstem schwannomas might differ from conventional schwannomas in their genetic background.

Preoperative stereotactic ablative body radiotherapy with postoperative conventional irradiation of soft tissue sarcomas: Protocol overview with a preliminary safety report.

e23546 Background: Preoperative radiotherapy in patients with soft tissue sarcomas is characterized by important advantages: high precision of dose delivery, reduction of tumour volume and implantation potential, induction of immunologic response. Postoperative irradiation is associated with a reduced risk of complication, and a comprehensive radiotherapy planning in accordance with the pathologic report. Combination of pre- and postoperative irradiation gives the opportunity to use the best of both methods. Methods: from 06.2018 to 01.2021 24 patients with soft tissue sarcomas of extremities were included in the protocol (NCT04330456) and 14 cases with at least 12 months follow-up were eligible for analysis. Preoperative stereotactic ablative body radiotherapy (SBRT) was performed as 5 fraction of 7 Gy with dose reduction (5 fractions of 5 Gy) on the margins of the tumor. Postoperative radiotherapy started 5-8 weeks after the surgery and was performed as standard compartmental irradiation in 25 fractions of 2Gy. Complications were determined according to CTCAE and wound complication scales. Results: Preoperative SBRT and subsequent radical resection with tumor free surgical margins were performed in all 14 cases. Primary wound closure was mentioned in all patients. Postoperative radiotherapy started 51.8 days (range 33-99 days) days after the surgery. With a relatively short follow-up of 21.5 (13-30) months, we recorded 2 cases (14%) of severe complications (Canadian sarcoma group criteria), and there were no local recurrences. Conclusions: Our preliminary results demonstrate that the combination of preoperative SBRT and postoperative conventional radiotherapy is feasible and does not increase the risk of postoperative complications. Clinical trial information: NCT04330456.

DEVIATION BETWEEN THE PLANNED DOSE AND THE IN VIVO DOSIMETRY RESULTS DURING POSTOPERATIVE IRRADIATION IN PATIENTS WITH UTERINE CANCER DEPENDING ON ANTHROPOMETRIC DATA

Topometry is an integral part of irradiation whose task is to repeat the position of the patient set by the simulator to repeat the PTV and the spatial relationship between the radiation field and the risk organs that were identified during planning. The dose distribution formulated in the plan is only an ideal model. There is some gap between the actual and planned dose distribution, especially in overweight patients. Objective: evaluate the effect of anthropometric data on the deviation between the planned dose and the results of dosimetry in vivo in patients with uterine cancer during postoperative irradiation. Materials and Methods. The authors analyzed the results of treatment of 110 patients with stage IB–II uterine cancer who were treated at the Department of Radiation Therapy of the Institute of Medical Radiology and Oncology of the National Academy of Medical Sciences of Ukraine from 2016 to 2019. The technique of classical fractionation was used with a single focal dose of 2.0 Gy 5 times a week, the total focal dose was 42.0–50.0 Gy. To assess the effect of the patient’s anthropometric data on the difference between the actual and calculated dose, the authors performed in vivo dosimetry after the first session and in the middle of the postoperative course of external beam radiation therapy. Results. Рatients with BSA < 1.92 m2, had the median relative deviation at the first session -4.12 %, after 20.0 Gy – 3.61 %, patients with BSA > 1.92 m2: -2.06 % and -1.55 % respectively. After 20 Gy 34.8 % of patients with BSA < 1.92 m2 there was an increase in deviation from the planned dose, 65.2 % a decrease, while in 56.1 % of patients with BSA > 1.92 m2 there was an increase, and in 43.9 % – its reduction. With increasing BMI, the actual dose received on the rectal mucosa in the tenth session of irradiation is approaching the calculated one. Conclusions. When irradiated on the ROKUS-AM device, we did not find a probable dependence of the influence of the constitutional features of patients between the received and planned radiation dose. When treated with a Clinac 600 C, only body weight and body mass index at the tenth irradiation session have a likely effect on the dose difference. Therefore, issues related to the individual approach to the treatment of uterine cancer, depending on anthropometric data is an urgent problem of modern radiotherapy. Key words: anthropometric data, obesity, radiation therapy, preradiation preparation, in vivo dosimetry, uterine cancer.

RARE-60. PREGNANCIES AFTER CHILDHOOD CRANIOPHARYNGIOMA – RESULTS OF KRANIOPHARYNGEOM 2000/2007

BACKGROUND Data on female fertility, pregnancy, and outcome of offspring after childhood-onset craniopharyngioma (CP) are rare. STUDY DESIGN Observational study on pregnancy rate and offspring outcome in female CP patients recruited in KRANIOPHARYNGEOM 2000/2007. RESULTS A total of 451 CP patients (223 female) have been recruited, and 269 (133 female) were postpubertal at study. Six of 133 female CP patients (4.5%) with median age of 14.9 years at CP diagnosis had 9 pregnancies, giving birth to 10 newborns. Three patients achieved complete surgical resections. No patient underwent postoperative irradiation. Five natural pregnancies occurred in 3 CP patients without pituitary deficiencies. Four pregnancies in 3 CP patients with hypopituitarism were achieved under assisted reproductive techniques (ART) (median 4.5 cycles, range: 3–6 cycles). Median maternal age at pregnancy was 30 years (range: 22–41 years). Six babies (60%) were delivered by caesarean section. Median gestational age at delivery was 38 weeks (range: 34–43 weeks); median birth weight was 2,920 g (range: 2,270– 3,520 g), the rate of preterm delivery was 33%. Enlargements of CP cysts occurred in 2 women during pregnancy. Other complications during pregnancy, delivery, and postnatal period were not observed. CONCLUSIONS Pregnancies after CP are rare and were only achieved after ART in patients with hypopituitarism. Close monitoring by an experienced reproductive physician is necessary. Due to a potentially increased risk for cystic enlargement, clinical, ophthalmological, and MRI monitoring are recommended in patients at risk. Perinatal complications, birth defects, and morbidity of mothers and offspring were not observed.

SURG-01. RISK OF TRACT RECURRENCE WITH STEREOTACTIC BIOPSY OF BRAIN METASTASES: AN 18-YEAR CANCER CENTER EXPERIENCE

BACKGROUND Stereotactic biopsy is increasingly performed on brain metastases (BrM) as improving cancer outcomes drive aggressive multimodality treatment, however the risk of tract recurrence for such biopsies, in both the upfront and recurrent settings, are poorly defined in an era defined by focused-irradiation paradigms. As such, the rate of tract recurrence was evaluated. METHODS A retrospective review was performed to identify stereotactic biopsies performed for BrM at Memorial Sloan Kettering Cancer Center from 2002-2020. Data including surgical indications, tumor type, radiographic characteristics, stereotactic planning, pre- and post-operative CNS-directed and systemic treatments, and clinical courses were collected. Recurrence was evaluated using RANO-BM criteria. RESULTS Four-hundred-and-seventy-nine patients underwent stereotactic intracranial biopsy for any diagnosis (&gt;80% were for gliomas or CNS lymphoma). Twenty-two (4.5%) were for pathologically-confirmed viable BrM and 91% of these underwent postoperative irradiation with either stereotactic radiotherapy (14/20, 70%; SBRT) in plans that did not specifically target the biopsy tract, or whole-brain irradiation (6/20, 30%; WBRT). Eleven patients (50%) had &gt;/=3 months radiographic follow-up (median 11.9; 4.5-30.6), of which 6 (55%) developed discontinuous enhancement along the tract at a median 6.4 months (2.3-17.1) post-biopsy. Of these, 2 had previously been treated with SBRT and were sampled in the setting of diagnostic ambiguity (one additionally with WBRT for small cell carcinoma) and underwent intraoperative laser interstitial thermal therapy (LITT) immediately following biopsy. The remainder were treated with SBRT +/- LITT (n=3 and 4, respectively) following biopsy. Tract recurrences were treated with resection (n=2, both with pathologic confirmation), re-irradiation (n=1) or observation/systemic therapy. CONCLUSIONS In this largest reported series of biopsied BrM, we identify a nontrivial rate, higher than previously described, of recurrence along stereotactic biopsy tracts. As BrM are most commonly treated with focused radiotherapy centered on enhancing tumor margins, consideration should be made to include biopsy tracts where feasible.

50. RISK OF TRACT RECURRENCE WITH STEREOTACTIC BIOPSY OF BRAIN METASTASES: AN 18-YEAR CANCER CENTER EXPERIENCE

BACKGROUND Stereotactic biopsy is increasingly performed on brain metastases (BrM) as improving cancer outcomes drive aggressive multimodality treatment, however the risk of tract recurrence for such biopsies, in both the upfront and recurrent settings, are poorly defined in an era defined by focused-irradiation paradigms. As such, the rate of tract recurrence was evaluated. METHODS A retrospective review was performed to identify stereotactic biopsies performed for BrM at Memorial Sloan Kettering Cancer Center from 2002–2020. Data including surgical indications, tumor type, radiographic characteristics, stereotactic planning, pre- and post-operative CNS-directed and systemic treatments, and clinical courses were collected. Recurrence was evaluated using RANO-BM criteria. RESULTS Four-hundred-and-seventy-nine patients underwent stereotactic intracranial biopsy for any diagnosis (&gt;80% were gliomas or CNS lymphoma). Twenty-two (4.5%) were for pathologically-confirmed viable BrM and 91% (20/22) of these underwent postoperative irradiation with either stereotactic radiotherapy (14/20, 70%; SBRT) in plans that did not specifically target the biopsy tract, or whole-brain irradiation (6/20, 30%; WBRT). Eleven patients (50%) had &gt;/=3 months radiographic follow-up (median 11.9; 4.5–30.6), of which 6 (55%) developed discontinuous enhancement along the tract at a median 6.4 months (2.3–17.1) post-biopsy. Of these, 2 had previously been treated with SBRT and were sampled in the setting of diagnostic ambiguity (one additionally with WBRT for small cell carcinoma) and underwent intraoperative laser interstitial thermal therapy (LITT) immediately following biopsy. The remainder were treated with SBRT +/- LITT (n=3 and 4, respectively) following biopsy. Tract recurrences were treated with resection (n=2, both with pathologic confirmation), re-irradiation (n=1) or observation/systemic therapy. CONCLUSIONS In this largest reported series of biopsied BrM, we identify a nontrivial rate, higher than previously described, of recurrence along stereotactic biopsy tracts. As BrM are most commonly treated with focused radiotherapy centered on enhancing tumor margins, consideration should be made to include biopsy tracts where feasible.

Pregnancies after Childhood Craniopharyngioma: Results of KRANIOPHARYNGEOM 2000/2007 and Review of the Literature

<b><i>Background:</i></b> Data on female fertility, pregnancy, and outcome of offspring after childhood-onset craniopharyngioma (CP) are rare. <b><i>Study Design:</i></b> Observational study on pregnancy rate and offspring outcome in female CP patients recruited in KRANIOPHARYNGEOM 2000/2007 since 2000. <b><i>Results:</i></b> A total of 451 CP patients (223 female) have been recruited, and 269 (133 female) were postpubertal at study. Six of 133 female CP patients (4.5%) with a median age of 14.9 years at CP diagnosis had 9 pregnancies, giving birth to 10 newborns. Three patients achieved complete surgical resections. No patient underwent postoperative irradiation. Five natural pregnancies occurred in 3 CP patients without pituitary deficiencies. Four pregnancies in 3 CP patients with hypopituitarism were achieved under assisted reproductive techniques (ART) (median 4.5 cycles, range: 3–6 cycles). Median maternal age at pregnancy was 30 years (range: 22–41 years). Six babies (60%) were delivered by caesarean section. Median gestational age at delivery was 38 weeks (range: 34–43 weeks); median birth weight was 2,920 g (range: 2,270–3,520 g), the rate of preterm delivery was 33%. Enlargements of CP cysts occurred in 2 women during pregnancy. Other complications during pregnancy, delivery, and postnatal period were not observed. <b><i>Conclusions:</i></b> Pregnancies after CP are rare and were only achieved after ART in patients with hypopituitarism. Close monitoring by an experienced reproductive physician is necessary. Due to a potentially increased risk for cystic enlargement, clinical, ophthalmological, and MRI monitoring are recommended in patients at risk. Severe perinatal complications, birth defects, and postnatal morbidity of mothers and offspring were not observed.