The role of stereotactic ablative radiotherapy in oncological and non-oncological clinical settings: highlights from the 7th Meeting of AIRO--Young Members Working Group (AIRO Giovani)

Brain Linac-Based Radiation Therapy: "Test Drive" of New Immobilization Solution and Surface Guided Radiation Therapy

AIM

To test inter-fraction reproducibility, intrafraction stability, technician aspects, and patient/physician's comfort of a dedicated immobilization solution for Brain Linac-based radiation therapy (RT).

METHODS

A pitch-enabled head positioner with an open-face mask were used and, to evaluate inter- and intrafraction variations, 1-3 Cone-Beam Computed Tomography (CBCT) were performed. Surface Guided Radiation Therapy (SGRT) was used to evaluate intrafraction variations at 3 time points: initial (i), final (f), and monitoring (m) (before, end, and during RT). Data regarding technician mask aspect were collected.

RESULTS

Between October 2019 and April 2020, 69 patients with brain disease were treated: 45 received stereotactic RT and 24 conventional RT; 556 treatment sessions and 863 CBCT's were performed. Inter-fraction CBCT mean values were longitudinally 0.9 mm, laterally 0.8 mm, vertically 1.1 mm, roll 0.58°, pitch 0.59°, yaw 0.67°. Intrafraction CBCT mean values were longitudinally 0.3 mm, laterally 0.3 mm, vertically 0.4 mm, roll 0.22°, pitch 0.33°, yaw 0.24°. SGRT intrafraction mean values were: i_, m_, f_ longitudinally 0.09 mm, 0.45 mm, 0.31 mm; i_, m_, f_ laterally 0.07 mm, 0.36 mm, 0.20 mm; i_, m_, f_ vertically 0.06 mm, 0.31 mm, 0.22 mm; i_, m_, f_ roll 0.025°, 0.208°, 0.118°; i_, m_, f_ pitch 0.036°, 0.307°, 0.194°; i_, m_, f_ yaw 0.039°, 0.274°, 0.189°.

CONCLUSIONS

This immobilization solution is reproducible and stable. Combining CBCT and SGRT data confirm that 1 mm CTV-PTV margin for Linac-based SRT was adequate. Using open-face mask and SGRT, for conventional RT, radiological imaging could be omitted.

Linac-based STereotactic Arrhythmia Radioablation (STAR) of ventricular tachycardia: Case report and literature review

Linac-based STereotactic Arrhythmia Radioablation (STAR) is a safety and effective approach for selected patients with ventricular arrhythmias.

The role of radiotherapy in epithelial ovarian cancer: a literature overview

Ovarian cancer (OC) accounts for 3% of all cancer in women and for 5% of all cancer-related deaths. Epithelial Ovarian Cancer (EOC) is a radiosensitive malignancy with a poor prognosis. In the pre-chemotherapy era, radiation therapy (RT) delivered to the abdominopelvic region (whole abdominal irradiation, WAI) has historically played a role in the adjuvant and consolidation setting. Specific cluster of patients with early-stage disease and definite histologies may take advantage of RT. Platinum-based chemotherapy (CT) has replaced RT and plays a major role in most of the clinical settings. Radiation Therapy for palliation is recommended in patients with localized symptoms. Nevertheless, modern RT represents a reliable treatment option, with a mild toxicity profile, particularly effective for oligo-recurrent or progressive disease. The present literature review aims to highlight the historical role of RT in EOC, the actual lines of evidence, and the future perspectives.

Linac-based radiosurgery or fractionated stereotactic radiotherapy with flattening filter-free volumetric modulated arc therapy in elderly patients : A mono-institutional experience on 110 brain metastases

AIM

The aim of this study was to analyze the feasibility and clinical results of linear accelerator (linac-)based stereotactic radiosurgery (SRS) or fractionated stereotactic radiotherapy (SFRT) with flattening filter-free (FFF) volumetric modulated arc therapy (VMAT) in elderly patients affected by brain metastases (BMs).

PATIENTS AND METHODS

Patients selected for the present analysis were ≥65 years old with a life expectancy of >3 months, a controlled or synchronous primary tumor, and <10 BMs with a diameter <3 cm. All patients were treated with FFF linac-based SRS/SFRT. The prescribed total dose (15-30 Gy/1-5 fractions) was based on BM size and proximity to organs at risk (OAR). Toxicity was assessed according to the Common Terminology Criteria for Adverse Events (CTCAE) v4.0. MedCalc v18.2 (MedCalc Software, Ostend, Belgium) was used for statistical analysis.

RESULTS

From April 2014 to December 2017, 40 elderly patients with 110 BMs were treated by FFF linac-based SRS/SFRT. With a median follow-up of 28 months (range 6-50 months), median and 1‑year overall survival were 9 months and 39%, respectively; median intracranial progression-free survival was 6 months. At the time of the analysis, local control was reported in 109/110 BMs (99.1%): 12 BMs had a complete response; 51 a partial response; 46 showed stable disease. One BM (0.9%) progressed after 2 months. BM volume (<1 cc) and higher SRS/SFRT dose correlated to treatment response (p = 0.01 and p = 0.0017, respectively). No adverse events higher than grade 2 were observed.

CONCLUSION

The present findings highlight the feasibility, safety, and effectiveness of FFF linac-based SRS/SFRT in elderly patients with BMs.

Evaluation of Italian radiotherapy research from 1985 to 2005: preliminary analysis

AIM

The difficulty in conducting meaningful clinical research is a multifactorial issue, involving political, financial and cultural problems, which can lead to unexpected negative long-term consequences, in terms of knowledge advancement and impact on patient care. The aims of the present review were to evaluate the publications of Italian radiotherapy (RT) groups during a 20-year period and to verify whether research is still appealing to young radiation oncologists (ROs) in Italy.

METHODS

PubMed database was searched for English-language articles published by Italian groups from January 1985 to December 2005. Analyzed variables were: publication/year, kind of study, geographical area and age of the first author.

RESULTS

The systematic review identified 3291 articles: 1207 papers fulfilled the inclusion criteria. The number of Italian published papers increased during the examined period. Retrospective analyses, prospective phase I-II trials and literature reviews were 44, 20 and 14.5% of all published manuscripts, respectively. Randomized trials showed a mild increase from 2000 to 2005, but their absolute number remained low respect to other types of studies (4%). Northern Italy produced the very most of Italian research papers (58.7%). The age of the first/second author was evaluated on 716 papers: In more than 50% of cases, the first author was younger than 40.

CONCLUSION

Despite a general gradual improvement, RT clinical research suffers in Italy (as elsewhere) from insufficient funding, with a negative impact on evidence production. It is worth noting that clinical research is still appealing and accessible to junior Italian RO.

Hepatobiliary scintigraphy allows the evaluation of short-term functional toxicity of liver stereotactic body radiotherapy: Results of a pilot study

PURPOSE

To study the potential of (99m)Tc-Mebrofenin hepatobiliary scintigraphy (HBS) in identifying the short-term variations of liver function after stereotactic body radiotherapy (SBRT) for liver cancers.

MATERIAL AND METHODS

We treated with SBRT 3 patients (pts) affected by a cholangiocarcinoma and 3 patient presenting liver metastases (3x15 Gy, 4 pts; 5x8 Gy, 1 pt; 6x5 Gy, 1 pt). All patients received HBS before and 3 months after SBRT, which were co-registered with the simulation CT-scan. Structures corresponding to isodoses from 10-90 Gy were created, with intervals of 10 Gy. Finally, the variations of the mean activity (MBq) in each isodose structure have been calculated. Then, a linear regression analysis was performed.

RESULTS

We showed a linear reduction of the activity, significantly related to the delivered dose (p<0.01), and a reduction of the perfusion of 0.78% for each delivered Gy. The linear equation has predictive value of the loss of the function of 96% (R2 = 0.9605).

CONCLUSIONS

HBS could improve treatment plans for liver SBRT, by allowing the identification of the liver function variations after SBRT and, potentially, the prediction of remnant liver function after SBRT. These preliminary results should be confirmed on long-term prospective data and larger population.

Role of functional imaging in treatment plan optimization of stereotactic body radiation therapy for liver cancer

We report the first known instance of the clinical use of 99mTc-mebrofenin hepatobiliary scintigraphy (HBS) for the optimization of radiotherapy treatment planning and for the follow-up of acute toxicity in a patient undergoing stereotactic body radiation therapy for hepatocellular carcinoma. In our experience, HBS allowed the identification and the sparing of more functioning liver areas, thus potentially reducing the risk of radiation-induced liver toxicity.

Combined Modality Therapy for Thoracic and head and Neck Cancers: A Review of Updated Literature Based on a Consensus Meeting

Purpose

Combined modality therapy is a mainstay option for thoracic malignancies and head and neck cancers. The integration of different strategies is based on the multidisciplinary approach of modern clinical oncology. Radiation oncologists have to be educated, trained, and updated to provide state-of-the-art care to cancer patients and thus educational meetings are crucial.

Methods

The Italian Association of Radiation Oncology Young Members Working Group (AIRO Giovani) organized its 8th national meeting, focused on combination therapy in lung, esophageal, and head and neck cancer (with a specific focus on larynx-preservation strategies for larynx/hypopharynx tumors), involving young professionals working in Italy. The meeting was addressed to young radiation oncologists, presenting state-of-the-art knowledge, based on the latest evidence in this field. We performed a review of the current literature based on the highlights of the Congress.

Results

The multimodality approach of head and neck and thoracic malignancies includes surgery, chemotherapy, and radiotherapy, but also has to take into account new information and data coming from basic and translational research and including molecular biology, genetics, and immunology. All these aspects are crucial for the treatment of non-small-cell lung cancer and esophageal, esophagogastric junction, and larynx/hypopharynx malignancies. The integration of different treatments in the clinical decision-making process to combine therapies is crucial.

Conclusions

Combination therapy has proved to be a consolidated approach in these specific oncologic settings, highlighting the importance of multimodality management in modern clinical oncology. Dedicated meetings on specific topics are helpful to improve knowledge and skills of young professionals in radiation oncology.