Safety Of Proton Beam Therapy Research Articles

Proton Beam Therapy for Lung Oligometastatic Recurrence in Patients With Esophageal Cancer.

Local treatment of oligometastatic esophagogastric cancer has been reported to improve overall survival (OS) compared to systemic therapy alone. This study evaluated the feasibility and safety of proton beam therapy (PBT) for the treatment of lung oligometastatic recurrence in esophageal cancer patients. This single-center historical cohort study enrolled 11 patients who underwent PBT for lung oligometastasis from esophageal cancer between 2010 and 2019. The selection criteria were that the primary esophageal cancer was controlled and no more than three lung metastases without outside lung tumors were present. OS, progression-free survival (PFS), and local control (LC) rates and adverse events (AEs) were assessed. Factors that may be related to OS were also investigated. The median follow-up period was 27.8 months (8.8-141.3 months). The one-, two-, and three-year OS rates were 81.8%, 72.7%, and 51.9%, respectively (median OS time: 43.7 months); PFS rates were 45.5%, 27.3%, and 27.3%, respectively (median PFS time: 8.8 months); and LC rates were 92.3%, 72.7%, and 72.7%, respectively. The eighth edition of tumor-node-metastasis (TNM) classification for esophageal cancer was the only significant OS-related factor (p = 0.0309). No grade ≥ 3 AEs were observed. Based on the low incidence of AEs and acceptable LC rate, PBT is a feasible option for the treatment oflung oligometastasis in esophageal cancer patients.

Proton therapy in the palliative setting.

Given its sharp dose fall off and ability to spare healthy surrounding tissue, proton beam therapy (PBT) has traditionally been used to treat various types of malignancies in the definitive setting, with strong, empirical data supporting its utility and safety. In the palliative setting, however, photon therapy has generally remained the standard of care in radiation treatment delivery due to lower cost, and greater availability. However, recent data suggest that the use of PBT may provide benefit in terms of symptom management and disease control in patients with locally advanced or recurrent disease who do not qualify for definitive therapy or with metastatic disease. Additionally, due to its unique dosimetric properties, PBT may confer less overall toxicity, thus helping preserve or improve the quality of life in this patient population, especially for those who are nearing end of life. While there is a need for further study, initial data analyzed from both retrospective and prospective single-institution and multi-institution trials are promising. This review aims to explore the efficacy and safety of PBT in the palliative setting among adults and to summarize pertinent studies that support its usage. To the authors' knowledge, this is the first review of the literature pertaining to PBT used in the palliative setting across multiple disease sites.

Proton Beam Therapy for Hepatocellular Carcinoma: Multicenter Prospective Registry Study in Japan

A prospective multicenter registry study was started May 2016 in Japan to evaluate the efficacy and safety of proton beam therapy (PBT) for hepatocellular carcinoma (HCC). Patients who received PBT for HCC from May 2016 to June 2018 were registered in the database of the Particle Beam Therapy Committee and Subcommittee of the Japanese Society for Radiation Oncology. Overall survival (OS), progression-free survival (PFS), and local recurrence were evaluated. Of the 755 registered patients, 576 with initial PBT and no duplicate cancer were evaluated. At final follow-up, 322 patients were alive and 254 had died. The median follow-up period for survivors was 39 months (0-58 months). The median OS time of the 576 patients was 48.8 months (95% CI, 42.0-55.6 months) and the 1-, 2-, 3-, and 4-year OS rates were 83.8% (95% CI, 80.5%-86.6%), 68.5% (64.5%-72.2%), 58.2% (53.9%-62.2%), and 50.1% (44.9%-55.0%), respectively. Recurrence was observed in 332 patients, including local recurrence in 45 patients. The median PFS time was 14.7 months (95% CI, 12.4-17.0 months) and the 1-, 2-, 3-, and 4-year PFS rates were 55.2% (95% CI, 51.0%-59.2%), 37.5% (33.5%-41.5%), 30.2% (26.3%-34.2%), and 22.8% (18.5%-27.4%), respectively. The 1-, 2-, 3-, and 4-year OS rates were significantly higher for tumor size <5 versus 5 to 10 cm (P < .001) and <5 versus ≥10 cm (P < .001); Child-Pugh score A/B versus C (P < .001); and distance of the tumor from the gastrointestinal tract <1 versus 1 to 2 cm (P < .008) and <1 versus >2 cm (P < .001). At final follow-up, 27 patients (4.7%) had late adverse events of grade 3 or higher, with liver failure (n=7), and dermatitis (n=7) being most common. This multicenter prospective data registry indicated that PBT for HCC gives good therapeutic effects (3-year local control rate of 90%) with a low risk of severe late adverse events.

Proton beam therapy for hepatocellular carcinoma with bile duct invasion

AimHepatocellular carcinoma (HCC) with bile duct invasion (BDI) (BDIHCC) has a poor prognosis. Moreover, due to the paucity of reports, there is no consensus regarding optimal management of this clinical condition yet. The aim of this study was to clarify the efficacy and safety of proton beam therapy (PBT) for BDIHCC.MethodsBetween 2009 and 2018, 15 patients with BDIHCC underwent PBT at our institution. The overall survival (OS), local control (LC), and progression-free survival (PFS) curves were constructed using the Kaplan-Meier method. Toxicities were assessed using the Common Terminology Criteria of Adverse Events version 4.0.ResultsThe median follow-up time was 23.4 months (range, 7.9–54.3). The median age was 71 years (range, 58–90 years). Many patients were Child A (n = 8, 53.3%) and most had solitary tumors (n = 11, 73.3%). Additionally, most patients had central type BDI (n = 11, 73%). The median tumor size was 4.0 cm (range, 1.5–8.0 cm). The 1-, 2-, and 3-year OS rates were 80.0%, 58.7% and 40.2%, respectively, and the corresponding LC and PFS rates were 93.3%, 93.3%, and 74.7% and 72.7%, 9.7%, and 0.0%, respectively. Acute grade 1/2 dermatitis (n = 7, 46.7%), and grades 2 (n = 1, 6.7%) and 3 (n = 1, 6.7%) cholangitis were observed. Late toxicities such as grade 3 gastric hemorrhage and pleural effusion were observed. No toxicities of grade 4 or higher were observed.ConclusionsPBT was feasible with tolerable toxicities for the treatment of BDIHCC.

The Effectiveness of Proton Beam Therapy for Liver Metastatic Lesions in Colorectal Cancer Patients

<h3>Purpose/Objective(s)</h3> The purpose of this study was to evaluate the efficacy and safety of proton beam therapy (PBT) for liver metastatic (LM) lesion in colorectal cancer (CRC) patients. <h3>Materials/Methods</h3> Consecutive CRC patients who underwent PBT for ≤3 LM lesions from 2009 to 2018 were isolated from our institutional database. Patients with extrahepatic metastatic lesions were excluded. The effectiveness was assessed based on the local control (LC), overall survival (OS) and progression-free survival (PFS) rates. The LC, OS and PFS rates were calculated using the Kaplan–Meier method and log-rank test. Factors that may be related to LC, such as tumor size, fraction size, BED₁₀ and the distance from the lesion to the most recently involved intestinal tract were investigated. The cut-off values were estimated using the ROC curve and AUC. P-values below 0.05 were consider significant. Adverse events were described according to CTCAE ver 5.0. <h3>Results</h3> This study included 23 men and 18 women whose median age was 66 years (24 - 87 years). Sixty-three lesions were enrolled. The most frequent dosage was 72.6 Gy (RBE) /22fr. The median lesion size, fraction size, BED₁₀, the distance between LM lesion and adjacent were 30 mm (9-103 mm), 3.3 Gy(RBE)/fr (2-8 Gy(RBE)/fr),105.6 Gy(RBE) (72-154.7 Gy(RBE)), 42.4mm (0-147mm), respectively. The median follow-up period was 27.6 months (5.2-84.7 months). As of November 2020, 20 patients died (including one of intercurrent disease death). The 3-year LC, OS and PFS rates were 54.9%, 61.6%, and 16.7%, respectively. Twenty-three lesions were local recurrence which of five lesions were surgically removed and one lesion was re-irradiated with PBT. Both re-treatments after PBT were performed safely and without complications. Distant metastasis occurred in 24 patients. The most common site of distant metastasis was the lung with 11 patients. Any statistically significant LC related factors were not found. However, the P-value for tumor size was the smallest, P=0.0665. The 2-year LC rates in the group with less than 14.1 mm and the larger group were 100% and 50%, respectively. and 50%, respectively. No grade ≥3 adverse events were observed. No patients experienced liver failure in the acute or late phase. The only acute adverse event was one cases of G2 dermatitis radiation. The only late adverse effect was three cases of G1 radiation-induced rib fracture. <h3>Conclusion</h3> PBT might be a treatment option for patients with liver metastasis of CRC. Tumor size tended to be associated with local control rates.

PO-620-03 ONCOLOGIC PROTON BEAM THERAPY IN PATIENTS WITH CARDIAC IMPLANTABLE ELECTRONIC DEVICES

Proton beam therapy (PBT) is an attractive treatment for malignancy owing to its high precision on target tissue while sparing adjacent sites. The safety of PBT in patients with cardiac implantable electronic devices (CIEDs) remains unclear.

Treatment outcomes of proton beam therapy combined with retrograde intra-arterial infusion chemotherapy for locally advanced oral cancer in the elderly

The aim of this study was to evaluate the therapeutic efficacy and safety of proton beam therapy combined with retrograde intra-arterial infusion chemotherapy in elderly patients with locally advanced oral cancer. Between February 2009 and October 2019, 42 oral cancer patients aged ≥75 years were treated with this therapy. Median age was 80 years (range 75–90 years) and the median follow-up duration was 39 months (range 2–106 months). Of the 42 patients, 34 (81%) were diagnosed with stage IV cancer. The 3-year overall survival, local control, progression-free survival, and disease-specific survival rates were 56%, 69%, 32%, and 67%, respectively. Regarding acute toxicities, grade 3 neutropenia was observed in six patients (14%), anaemia in five (12%), acute kidney injury in one (2%), and oral mucositis in 18 (42%). Late toxicities of grade 3 were observed in seven patients: dysphagia in six (14%) and osteonecrosis of the jaw in one (2%). This study showed that proton beam therapy combined with retrograde intra-arterial infusion chemotherapy was effective for elderly patients with oral cancer, and toxicities were tolerable and manageable. The study findings suggest that this therapy is a potential treatment option for elderly oral cancer patients with difficulty in surgery and systemic chemotherapy.

The effectiveness of proton beam therapy for liver metastatic recurrence in gastric cancer patients

The purpose of this cross-sectional study was to evaluate the efficacy and safety of proton beam therapy for liver metastatic recurrence in gastric cancer patients. Consecutive patients who underwent proton beam therapy from 2010 to 2015 were isolated from our institutional database. Patients with extrahepatic metastatic lesions were excluded. Seven patients were enrolled. The median diameter of target lesions was 31mm (13-68mm). The most frequent dosage was 72.6Gy equivalent in 22 fractions. The effectiveness was assessed based on the local control, overall survival and progression-free survival rates. The local control, overall survival and progression-free survival rates were calculated using the Kaplan-Meier method. Adverse events were described according to the patients' medical records. The median follow-up period was 41.7months (20.7-66.3months). The 3-year local control, overall survival and progression-free survival rates were 85.7, 68.6 and 43%, respectively. All patients completed proton beam therapy without interruption. No grade ≥3 adverse events were observed. Proton beam therapy might be a treatment option for patients with liver metastasis of gastric cancer.

Proton Beam Therapy for Histologically or Clinically Diagnosed Stage I Non-Small Cell Lung Cancer (NSCLC): The First Nationwide Retrospective Study in Japan

To investigate the efficacy and safety of proton beam therapy (PBT) for the treatment of stage I non-small cell lung cancer (NSCLC). Six hundred sixty-nine patients with 682 tumors histologically or clinically diagnosed stage I NSCLC according to the seventh edition of Union for International Cancer Control who received passive-scattering PBT from April 2004 and December 2013 in Japan were retrospectively reviewed to analyze survival, local control, and toxicities. Of 669 patients, 486 (72.6%) were men, with a median age of 76 years (range, 42-94 years). NSCLC was histologically confirmed in 440 patients (65.7%). Clinical T stages included T1a (n = 265; 38.9%), T1b (n = 216; 31.7%), and T2a (n = 201; 29.4%). The total irradiation doses of PBT ranged from 74.4 to 131.3 biological effective dose GyE (median, 109.6 biological effective dose GyE). The median follow-up period was 38.2 months (range, 0.6-154.5 months) for all patients. The 3-year overall survival and progression-free survival rates for all patients were 79.5% and 64.1%, respectively. For patients with stage IA tumors, the 3-year overall survival and progression-free survival rates were 82.8% and 70.6%, respectively, and the corresponding rates for patients with stage IB tumors were 70.8% and 47.3%, respectively. The 3-year local progression-free rates for all, stage IA, and stage IB patients were 89.8%, 93.5%, and 79.4%, respectively. The incidence of grade 2, 3, 4, and 5 pneumonitis was 9.8%, 1.0%, 0%, and 0.7%, respectively. The incidence of grade ≥3 dermatitis was 0.4%. No grade 4 or severe adverse events, other than pneumonitis, were observed. PBT appears to yield acceptable survival rates, with a low rate of toxicities.

Clinical results of proton beam therapy for elderly patients with non-small cell lung cancer

BackgroundThe purpose of the present study was to evaluate retrospectively the efficacy and safety of proton beam therapy for elderly patients (≥80 years of age) with non-small cell lung cancer.MethodsPatients diagnosed with T1–4 N0 M0 non-small cell lung cancer and treated with proton beam therapy between January 2009 and 2015 were recruited from our database retrospectively. Toxicity was evaluated using The Common Terminology Criteria for Adverse Events version 4.0.ResultsThirty-five patients, including 25 (71%) with clinically inoperable lung cancer, were administered proton beam therapy. The median age was 82 years (range: 80–87 years), and the median follow-up time was 34 months (range: 10–72 months). The median dose of proton beam therapy was 80.0 Gy relative biological effectiveness (RBE) (range: 60.0–80.0 Gy [RBE]), and all patients completed the treatments. All patients were followed for at least 23 months or until their death. The 3-year overall survival rate was 67.2% (90.0% in patients with operable lung cancer, and 58.2% in those with inoperable lung cancer). The 3-year local control rate was 86.5%. Two patients presented with grade 2 pneumonitis. The occurrence rate of grade 2 pneumonitis was significantly correlated with a high lung V20 (p = 0.030), and a high mean lung dose (p = 0.030), and a low ratio of lung volume spared from 0.05 Gy (RBE) dose (total lung volume minus lung volume irradiated at least 0.05 Gy [RBE]) (p = 0.030). However, there were no cases of grade 3 or higher radiation pneumonitis.ConclusionsThis study suggests that the proton beam therapy was feasible for elderly patients with non-small cell lung cancer and can be considered as one of the treatment choices for elderly patients with lung cancer.

Effect and safety of proton beam therapy for locally recurrent rectal cancer.

743 Background: The first choice of treatment for locally recurrent rectal cancer is surgical resection. However, the operation is often difficult with high perioperative risk. For surgically unfit cases, proton beam therapy (PBT) is proposed as the treatment option. However, its efficacy for locally recurrent rectal cancer remains unclear. Therefore, this study aimed to evaluate the efficacy and safety of PBT for locally recurrent rectal cancer. Methods: A total of 23 patients with locally recurrent rectal cancer who received PBT were retrospectively evaluated, from November 2005 to July 2014. Patients with single lesion, who refuse the radical surgical therapy, or who were considered unfit for the operation were included in this study. All patients were treated with 2.8Gy relative biological effectiveness (RBE)/fraction. Twenty-five irradiations were performed, with a total irradiation of 70Gy RBE. Unfit for operation criteria include invasion to the vertebra higher than the third sacrum or lateral lymph node recurrence after a lateral lymph node dissection. To assess the safety of PBT, adverse events were evaluated by using the Common Terminology Criteria for Adverse Effects (CTCAE version4.0). To assess the efficacy, the overall and relapse-free survival rates and local control rate were evaluated. Results: Sixteen patients were unfit for operation, and seven refused surgery. Three patients experienced Grade 3 late adverse events in the CTCAE (two ileum fistula and one urinary tract obstruction). The median follow-up time was 28.9 months. The 5-year overall and relapse-free survival rates were 47.6% and 20.2%, respectively. Fifteen patients (65.2%) showed distant metastasis or regrowth at the locally recurrent site. The 5-year local control rate was 39.0%. Ten patients (43.4%) showed regrowth at the proton beam irradiation site. Conclusions: PBT was relatively effective for locally recurrent rectal cancer with manageable adverse effects. Therefore, PBT may be considered as the therapeutic option for selected locally recurrent rectal cancer patients.

Protontherapy of head and neck paragangliomas: A monocentric study

PurposeThe aim of this study was to assess efficacy and safety of proton beam therapy of paragangliomas of the head and neck, rare benign tumours developed close to crucial structures such as cranial nerves and vascular tissues. Patients and methodsTen patients with a paraganglioma of the head and neck were treated from 2001 to 2014 with image-guided proton therapy. Neurological and ear nose throat symptoms were collected in addition to audiometric testing, before and after the treatment. Acute and late toxicities were assessed according to the Common Terminology Criteria for Adverse Events (CTCAE) v4. ResultsMedian age at diagnosis was 52.6years (range: 18.2–65.8years). Proton therapy was the exclusive treatment in six patients and four patients had a postoperative radiotherapy. Median dose was 50.4Gy relative biological effectiveness (RBE; range: 45.0–67.0Gy). With a median follow-up of 24.6months (range: 6.7–46.2 months), local tumour control rate was 100% (stable, n=10). No upper grade 2 acute toxicity was reported. To the latest news, seven patients had controlled symptoms (improved, n=1, stabilized, n=6). One patient out of seven with initial tinnitus had a decrease in his symptoms, while the six other patients had a sustained stabilization. ConclusionProton beam therapy is an effective and well-tolerated treatment modality of skull base paragangliomas, with documented functional benefit. A longer follow-up is planned in order to assess local control and long-term toxicities.

A retrospective study of late adverse events in proton beam therapy for prostate cancer.

The efficacy and safety of proton beam therapy (PBT) were retrospectively evaluated in 111 consecutive patients with prostate cancer who underwent definitive PBT between 2008 and 2012. Following exclusion of 18 patients due to treatment suspension, loss to follow-up, and histology, the analysis included 93 patients with a median age of 68 years (range, 49–81 years). A total of 7, 32 and 54 prostate cancer patients were classified as low-, intermediate- and high-risk, respectively, as follows: High-risk, T≥3a or prostate-specific antigen (PSA) ≥20 ng/ml or Gleason Score ≥8; low-risk, T ≤2b and PSA≤10 ng/ml and Gleason Score=6; intermediate-risk, all other combinations. The median initial prostate-specific antigen (PSA) level was 9.75 ng/ml (range, 1.4–100 ng/ml) and the median Gleason score was 7 (range, 6–10). Patients with low-risk disease received 74 GyE (relative biological effectiveness=1.1) in 37 fractions, and those at intermediate or higher risk received 78 GyE in 39 fractions. Complete androgen blockade (CAB) therapy was performed from 6 months prior to PBT for patients with intermediate- or high-risk disease. CAB was continued during PBT and then terminated at the end of PBT for intermediate-risk patients. Patients at high risk continued CAB for 3 years. No combination therapy was used for low-risk patients. All the patients were followed up for >2 years after PBT, and all but one were PSA failure-free. The Common Terminology Criteria for Adverse Events v.4.0 was used to evaluate late adverse events. One patient developed grade 3 non-infectious cystitis and hematuria. Grade 2 urinary frequency was observed in 1 patient, and grade 2 rectal bleeding occurred in 4 patients. Of the 4 patients with grade 2 rectal bleeding, 2 received anticoagulant therapy, but none had diabetes mellitus or another high-risk comorbidity. The median time to occurrence of an adverse event of grade ≥2 was 14 months (range, 3–41 months). Therefore, the present retrospective study revealed that PBT at 78 GyE/39 Fr was well-tolerated and achieved good tumor control in patients with prostate cancer.

Proton Beam Therapy for Locally Recurrent Parotid Gland Cancer.

The aim of this study was to evaluate the efficacy and safety of proton beam therapy for patients with locally recurrent parotid cancer. Between 2009 and 2012, ten patients with locally recurrent parotid gland cancer were treated with proton beam therapy (70.2Gy equivalents in 32 fractions) with or without intra-arterial infusion chemotherapy of cisplatin (50mg/body/week, for a total of 5-8weeks). The median follow-up was 24months (range 10-49months). The 1-year overall survival and local control rates were 80%, and the 3-year overall survival and local control rates were 60%. None of the patients experienced grade 3-5 toxicities in the treatment or the follow-up periods. These findings suggest that proton beam therapy could be applied effectively and safely for patients with locally recurrent parotid gland cancer.

Preliminary treatment results of proton beam therapy with chemoradiotherapy for stage I-III esophageal cancer.

The effect of proton beam therapy (PBT) on various cancers is controversial. We aimed to evaluate the efficacy and safety of PBT with alternating chemoradiotherapy (ACRT) for patients with stage I–III esophageal cancer. Two cycles of systemic chemotherapy with a continuous infusion of 5‐fluorouracil (5‐FU) on days 1–5 and a 5h infusion of nedaplatin (NDP) on day 6 were accompanied by thoracic irradiation using X‐ray therapy and PBT. During the first half of the treatment, X‐rays were delivered to the prophylactic area. During the second half of the treatment, proton beams were used to irradiate the involved field. To reduce the dose of cardiac irradiation, proton beams were delivered with posterior and posterior oblique angles. Between January 2009 and December 2012, 47 patients were enrolled in this study. The median follow‐up duration was 29 months for all patients and 40 months for survivors. The 3 year overall survival rate, progression‐free survival rate, and local control rate were 59.2%, 56.3%, and 69.8%, respectively. With respect to grade 3–4 late toxicities, there were no pleural or pericardial effusions, but two patients (4.3%) had esophageal stenosis, one patient (2.1%) had fistula, and two patients (4.3%) developed radiation pneumonitis. PBT with ACRT might have the potential to reduce the risk of cardiac damage and might become one of the primary methods of esophageal cancer treatment.

Clinical results of proton beam therapy for twenty older patients with esophageal cancer.

BackgroundIn an aging society, increasing number of older patients are diagnosed with esophageal cancer. The purpose of this study was to assess the clinical efficacy and safety of proton beam therapy for older patients with esophageal cancer.Patients and methods.Older patients (age: ≥ 65 years) newly diagnosed with esophageal cancer between January 2009 and June 2013 were enrolled in this study. All patients underwent either proton beam therapy alone or proton beam therapy with initial X-ray irradiation. Toxicities were evaluated using the Common Terminology Criteria for Adverse Events version 4.0.ResultsTwenty patients were eligible for this study and all completed the treatment. The median age was 78 years (range: 65–89 years) and the median follow-up time was 26.5 months (range: 6–62 months). Seven patients had lymph node metastases and 10 had stage II/III cancer. The median dose of proton beam therapy was 72.6 Gy relative biological dose effectiveness (RBE) (range: 66–74.8 Gy [RBE]) for proton beam therapy alone and 33 Gy (RBE) (range: 30.8–39.6 Gy [RBE]; total dose range: 66.8–75.6 Gy [RBE]) for proton beam therapy with initial X-ray irradiation. The 2-year overall survival rate was 81.8% (95% confidence interval [CI]: 62.4%–100%), and the 2-year local control rate was 89.4% (95% CI: 75.5%–100%). Grade 2 or 3 toxicities occurred in some cases; however, no grade 4 or 5 toxicity was observed.ConclusionsHigh-dose (66–75.6 Gy [RBE]) proton beam therapy without chemotherapy was an efficacious and safe treatment for older patients with esophageal cancer.

Improving the Delivery and Safety of Proton Beam Therapy

mice per group for a total of 72 measurements. A t–test was used to determine differences in values between treatment groups (radiation + soy, radiation alone, and control). Results: Radiation caused significant thickening of the IEL, mean 66.5+/4.3um (SEM) compared with 22.7+/-0.8um IEL thickness in control mice (p<0.0001). When radiation was combined with soy treatment, IEL thickening was significantly reduced, measuring 37.2+/-1.1um compared with radiation alone (p<0.0001). The change in IEL thickness for irradiated mice was histologically characterized by an increased presence of inflammatory cells and fibroblasts, whereas the IEL in radiation + soy treated mice showed cellularity comparable to that of control. Conclusions: Thoracic radiation instigated an inflammatory response in the esophagus characterized by inflammatory cell infiltrate and subepithelial thickening, which was markedly attenuated by soy treatment. Our data suggest a radioprotective effect of soy isoflavones on esophageal tissues and warrant further investigation to describe the mechanisms responsible for these findings. Author Disclosure: M.M. Dominello: None. M. Fountain: None. L. Abernathy: None. M. Kirsch: None. C. Yunker: None. M. Joiner: None. F. Lonardo: None. G. Hillman: None.

Résultats de la protonthérapie ciblée fractionnée dans le traitement des méningiomes primitifs de la gaine du nerf optique

Optic nerve sheath meningioma (ONSM) is a common benign neoplasm arising from the arachnoid tissue encapsulating the optic nerve and affects mainly middle aged women. It is a slow-growing tumor for which there is still no consensus on treatment. To evaluate the safety and efficacy of fractionated targeted proton beam therapy (PBT) in the treatment of ONSM and to define its role in the treatment of these tumors. We performed a retrospective analysis of 15 patients (13 women and 2 men), mean age 41.8 years, presenting with primary ONSM, followed at the Fondation Ophtalmologique Adolphe de Rothschild (Paris) between September 2006 and August 2013. After a multidisciplinary consultation, all were treated with PBT at a total dose of 52.2 Gy Eco, in fractions of 1.8 Gy Eco, at the Institut Curie (Paris). Patients underwent standardized follow-up including ophthalmologic examinations, visual field testing and imaging every 6 months. Study parameters were post-treatment visual acuity, tumor size on MRI, and treatment side effects We separated the patients into 3 distinct groups: patients treated by PBT after an observation period (4/15), patients treated by PBT after primary surgery (5/15) and patients treated by PBT as primary treatment (6/15). Visual acuity improved in 3 cases, deteriorated in 1 and remained stable in 11 cases. Tumor size on MRI remained stable in 100 % of cases following PBT. No serious adverse effects were recorded after a mean follow-up of 22.4 months (8-79 months). Our experience confirms the efficacy and the safety of proton beam therapy in patients with ONSM. PBT presents a promising alternative to surgery and conventional radiotherapy in the treatment of the MGNO. It seems to be effective in controlling tumor size and stabilizing visual function, at the cost of very low toxicity. Additional studies are needed to accurately determine the decision-making criteria and the ideal timing of this treatment.

Effectiveness and safety of proton beam therapy for advanced hepatocellular carcinoma with portal vein tumor thrombosis

To evaluate the clinical effectiveness and safety of proton beam therapy (PBT) in advanced hepatocellular carcinoma (HCC) patients with portal vein tumor thrombosis (PVTT). Twenty-seven HCC patients with PVTT underwent PBT, including 22 patients with modified International Union Against Cancer (mUICC) stage IVA,five patients with stage IVB primary tumors, and 16 with main PVTT. A median dose of 55 GyE (range, 50-66 GyE) in 20-22 fractions was delivered to a target volume encompassing both the PVTT and primary tumor. Overall, treatment was well tolerated, with no toxicity of grade ≥ 3. Median overall survival (OS) times in all patients and in stage IVA patients were 13.2 months and 16 months, respectively. Assessments of PVTT response showed complete response in 0 of 27 (0%) patients, partial response in 15 (55.6%), stable disease in 10 (37%), and progressive disease in 2 (7.4%) patients, with an objective response rate of 55.6%. PVTT responders showed significantly higher actuarial 1-year local progression-free survival (LPFS; 85.6% vs. 51.3%), relapse-free survival (RFS; 20% vs. 0%) and OS (80% vs. 25%) rates than nonresponders (p<0.05 each). Multivariate analysis showed that PVTT response and mUICC stage were independent prognostic factors for OS. Our data suggest that PBT could improve LPFS, RFS, and OS in advanced HCC patients with PVTT and it is feasible and safe for these patients.

EP-1274: Effectiveness and safety of proton beam therapy for hepatocellular carcinoma with portal vein tumour thrombosis

EP-1274: Effectiveness and safety of proton beam therapy for hepatocellular carcinoma with portal vein tumour thrombosis