The study aimed to compare the dosimetric performance of Acuros® XB (AXB) and anisotropic analytical algorithm (AAA) for lung SBRT plans using Monte Carlo (MC) simulations.

We compared the dose calculation algorithms AAA and either of the dose reporting modes of AXB (dose to medium (AXB-Dm) or dose to water (AXB-Dw)) algorithms implemented in Eclipse® (Varian Medical Systems, Palo Alto, CA) Treatment planning system (TPS) with MC. PRIMO code was used for the MC simulations. The TPS-calculated dose profiles obtained with a multi-slab heterogeneity phantom were compared to MC. A lung phantom with a tumour was used to validate TPS algorithms using different beam delivery techniques. 2D gamma values obtained from Gafchromic film measurements in the tumour isocentre plane were compared with TPS algorithms and MC. Ten VMAT SBRT plans generated in TPS with each algorithm were recalculated with a PRIMO MC system for identical beam parameters for the clinical plan validation. A dose–volume histogram (DVH) based plan comparison and a 3D global gamma analysis were performed.

AXB demonstrated better agreement with MC and film measurements in the lung phantom validation, with good agreement in PDD, profiles and gamma analysis. AAA showed an overestimated PDD, a significant difference in dose profiles and a lower gamma pass rate near the field borders. With AAA, there was a dose overestimation at the periphery of the tumour. For clinical plan validation, AXB demonstrated higher agreement with MC than AAA.

AXB provided better agreement with MC than AAA in the phantom and clinical plan evaluations.

Induction chemotherapy (iC) followed by concurrent chemoradiation has been shown to improve overall survival (OS) for locally advanced pancreatic cancer (LAPC). However, the survival benefit of stereotactic body radiation therapy (SBRT) versus conventionally fractionated radiation therapy (CFRT) following iC remains unclear.

The National Cancer Database (NCDB) was queried for primary stage III, cT4N0-1M0 LAPC (2004–15). Kaplan–Meier analysis, Cox proportional hazards method and propensity score matching were used.

Among 872 patients, 738 patients underwent CFRT and 134 patients received SBRT. Median follow-up was 24·3 and 22·9 months for the CFRT and SBRT cohorts, respectively. The use of SBRT showed improved survival in both the multivariate analysis (hazards ratio 0·78, p = 0·025) and 120 propensity-matched pairs (median OS 18·1 versus 15·9 months, p = 0·004) compared to the CFRT.

This NCDB analysis suggests survival benefit with the use of SBRT versus CFRT following iC for the LAPC.

Partial breast irradiation (PBI) can reduce the volume of treatment and number of treatment sessions in low-risk breast cancer patients. Stereotactic body radiotherapy (SBRT) allows the administration of high doses per fraction thereby reducing the number of fractions and reducing the dose to the surrounding tissues. The objective of this study is to review the literature on the use of SBRT in PBI using the Cyberknife® (CK) unit.

In this review, we analysed the literature in PubMed and MEDLINE with articles published in the last 10 years. All citations were evaluated for relevant content and validity.

We include articles in the English language with information about PBI, SBRT in PBI, the use of the CK unit in PBI and other applications of SBRT in breast carcinoma. A total of 68 articles were found and 28 articles were selected for inclusion in this review.

The treatment of PBI using the CK unit has clear advantages in reducing the treatment volume, and therefore theoretically reducing side effects and good cosmetic results with adequate tumour control. However, the placement of fiducial markers is necessary, requiring an adequate learning curve for the placement of the markers and longer treatment times.

Choroidal metastases are the most frequent intraocular secondary tumours, with a prevalence of 2–7% according to the literature. Our aim was to review a clinical case of choroidal metastasis.

We present a case of a 63-year-old male patient diagnosed in 2018 with lung adenocarcinoma cT4N0M1. The patient had three metastases in the brain, which were successfully treated with radiosurgery (RS). The patient was treated with chemotherapy with pemetrexed–cisplatin schedule. Five months after diagnosis, the patient presented with decreased vision in the right eye. After ophthalmologic evaluation, he was diagnosed with a right choroidal metastasis, which was treated with external beam radiotherapy with 20 Gy in five fractions, resulting in improved visual acuity and a complete clinical and radiological response.

The patient took part in a clinical trial that continued with systemic chemotherapy. Twenty-two months after radiotherapy to the eye, the patient has good visual acuity without any side effects.

Choroidal metastasis treated with radiotherapy achieves good local control, with limited side effects, allowing an improvement in visual acuity and consequently, an improvement in the patient´s quality of life.

Treatment of metachronous second primary non-small cell lung cancer (NSCLC) in patients already treated with definitive radiotherapy is a matter of debate, since most patients are excluded from surgical treatment, which remains a therapeutic standard for patients with isolated lung masses. Salvage chemotherapy or immunotherapy alone offers a low probability of disease control. The option of re-irradiation often remains the only viable, but the risks of severe acute or late toxicities affecting the surrounding normal tissues make this a real clinical challenge.

From January 2015 to April 2018, five patients (male/female: 4/1; age 54–81 years, median 68) with previously irradiated NSCLC presented with a second primary lung tumour.

A partial response was seen in four patients, one complete responses in the fifth. The toxicity was low: two patients experienced a grade 2 asymptomatic radiation pneumonitis after 6 and 12 months from the end of stereotactic body radiation therapy, resolved with cortisone therapy. No acute or late oesophageal or cardiac toxicity was found.

In this work, we present our initial experience about the use of stereotactic radiotherapy technique in already irradiated patients. We reported a local disease control in all cases with an acceptable toxicity.

Stereotactic body radiotherapy (SBRT) is widely used for the treatment of stage-I non-small cell lung cancer (NSCLC). Patient-specific motion correlated with 4DCT could be essential for hypofractionated SBRT. All patients undergoing SBRT do not require motion management during the dose delivery. The objective of this study was to evaluate which patient may benefit from Gated SBRT.

Treatment planning of 20 patients of stage-I NSCLC was analysed. Conventional and 4DCT scans were taken. Internal target volume as well as planning target volume (ITV and PTV) were determined in the CT data sets. PTVall phases created using 4DCT data sets and PTV15mm created using conventional CT data were compared. Also, ITVall phases were compared with ITV created from maximum intensity projections (ITVMIP). Suitability of patients for motion management-based treatment delivery was also evaluated.

The average ITVMIP to ITVall phases ratio is 1·06 indicating good agreement between them. Based on the ratio of intensity projections, 9 out of 17 patients were found suitable for our existing gated treatment.

4D CT is the main requirement in SBRT to identify the patients who can benefit from motion management during the dose delivery.

A systematic literature review of six computerised databases was undertaken in order to review and summarise a forward planned lung stereotactic ablative body radiotherapy (SABR) treatment planning (TP) technique as a starting point for clinical implementation in the author’s department based on current empirical research. The data were abstracted and content analysed to synthesise the findings based upon a SIGN quality checklist tool.

A four-dimensional computed tomography scan should be performed upon which the internal target volume and organs at risk (OAR) are drawn. A set-up margin of 5 mm is applied to account for inter-fraction motion. The field arrangement consists of a combination of 7–13 coplanar and non-coplanar beams all evenly spaced. Beam modifiers are used to assist in the homogeneity of the beam, although a 20% planning target volume dose homogeneity is acceptable. The recommended fractionations by the UK SABR Consortium are 54 Gy in 3 fractions (standard), 55–60 Gy in 5 fractions (conservative) and 50–60 Gy in 8–10 fractions (very conservative). Conformity indices for both the target volume and OAR will be used to assess the planned distribution.

An overview of a clinically acceptable forward planned lung SABR TP technique based on current literature as a starting point, with a view to inverse planning with support from the UK SABR Consortium mentoring scheme.

A retrospective planning study comparing volumetric arc therapy (VMAT) and stereotactic body radiotherapy (SBRT) treatment plans for non-small cell lung cancer (NSCLC).

Five randomly selected early stage lung cancer patients were included in the study. For each patient, four plans were created: the SBRT plan and three VMAT plans using different optimisation methodologies. A total of 20 different plans were evaluated. The dose parameters of dose conformity results and the target dose constraints results were compared for these plans.

The mean planning target volume (PTV) for all the plans (SBRT and VMAT) was 18·3 cm3, with a range from 15·6 to 20·1 cm3. The maximum dose tolerance to 1 cc of all the plans was within 140% (84 Gy) of the prescribed dose, and 95% of the PTV of all the plans received 100% of the prescribed dose (60 Gy). In all the plans, 99% of the PTV received a dose >90% of the prescribed dose, and the mean dose in all the plans ranged from 67 to 72 Gy. The planning target dose conformity for the SBRT and the VMAT (0°, 15° collimator single arc plans and dual arc) plans showed the tightness of the prescription isodose conformity to the target.

SBRT and VMAT are radiotherapy approaches that increase doses to small tumour targets without increasing doses to the organs at risk. Although VMAT offers an alternative to SBRT for NSCLC and the potential advantage of VMAT is the reduced treatment times over SBRT, the statistical results show that there was no significant difference between the SBRT and VMAT optimised plans in terms of dose conformity and organ-at-risk sparing.