Centrally located early-stage non-small cell lung cancer in patients who are unfit for surgery are treated with fractionated radiotherapy. We present the outcomes of a moderately hypofractionated accelerated dose regimen of 50 Gy in 15 fractions from a single centre in the UK.

Electronic case notes and radiotherapy records of lung cancer patients treated between January 2014 and December 2016 were retrospectively reviewed. Adult Comorbidity Evaluation-27 score was used to evaluate comorbidities. Mean lung doses and percentage of lung receiving more than 20 Gy were calculated for all patients. Survival outcomes were estimated using Kaplan–Meier curves.

Fifty-three patients were included in the study; the median follow-up was 20.2 months. 87% of patients had stage I disease. There was no 30-day post-treatment mortality. Ninety-day mortality rate after radiotherapy was 3.8%. Grade 2 pneumonitis was seen in five patients while no grade 3 or 4 pneumonitis was observed. The median progression-free survival (PFS) and overall survival (OS) were 18.5 months and 28.2 months, respectively. The estimated 1 and 2 years PFS were 62.3% and 41.3%, respectively, and OS were 77.4% and 56.6%, respectively. Worsening performance status was associated with worse survival on cox regression analysis. Disease relapsed in 36% of patients. 7.5% of patients with relapsed disease had infield recurrence.

50 Gy in 15 fractions radiotherapy for central early-stage lung cancer is a feasible choice that requires further randomised trials.

To study the effect of deep inspiration breath hold (DIBH) on Fast-Forward trial for left-sided breast radiotherapy dosimetrically using tangential field-in-field (FiF), flattening filtered volumetric-modulated arc therapy (FF-VMAT) and flattening filter free volumetric-modulated arc therapy (FFF-VMAT) in comparison with free breathing (FB).

Computed tomography images were acquired on 15 patients with carcinoma of left breast in FB and DIBH. Planning target volume (PTV) and organs at risk were contoured on both image sets. Dose of 26 Gy in five daily fractions was prescribed to PTV. FiF, FF-VMAT and FFF-VMAT plans were created in treatment planning system on both FB and DIBH. PTV V95%, V107%, D0·1 cc, CI and HI, heart V1·5 Gy, V7 Gy, lung left V8 Gy, monitor units (MU) and beam ON time were used for evaluation. Different technique analysis in same breathing condition and FB versus DIBH for same planning technique were performed.

Mean of all 15 patients was reported as mean ± 1 standard deviation. PTV V95% was 97·55 ± 0·10 (FiF), 95·75 ± 0·66 (FF-VMAT) and 96·15 ± 0·46 (FFF-VMAT) in FB while 97·34 ± 0·50 (FiF), 96·03 ± 0·71 (FF-VMAT) and 95·86 ± 0·63 (FFF-VMAT) in DIBH. Heart V7 Gy was 8·53 ± 4·26 (FiF), 8·86 ± 2·20 (FF-VMAT) and 9·27 ± 2·46 (FFF-VMAT) in FB while 6·30 ± 2·98 (FiF), 5·23 ± 2·20 (FF-VMAT) and 4·68 ± 2·01 (FFF-VMAT) in DIBH. p-value of heart V7 Gy between FB and DIBH was 0·278 (FiF), 0·009 (FF-VMAT) and 0·003 (FFF-VMAT). Beam ON time for FFF-VMAT was reduced by 65% (FF-VMAT) and 11% (FiF).

Conformal dose to PTV was achieved better with VMAT plans. FFF-VMAT was delivered in less time compared to FF-VMAT and FiF for 26 Gy in five fractions. Heart dose can be significantly minimised with DIBH for VMAT plans.

To investigate the impact of intra-fractional motion on dose distribution in patients treated with intensity-modulated radiotherapy (IMRT) for lung cancer.

Twenty patients who had undergone IMRT for non-small cell lung cancer were selected for this retrospective study. For each patient, a four-dimensional computed tomography (CT) image set was acquired and clinical treatment plans were developed using the average CT. Dose distributions were then recalculated for each of the 10 phases of respiratory cycle and combined using deformable image registration to produce cumulative dose distributions that were compared with the clinical treatment plans.

Intra-fractional motion reduced planning target volume (PTV) coverage in all patients. The median reduction of PTV covered by the prescription isodose was 3·4%; D98 was reduced by 3·1 Gy. Changes in the mean lung dose were within ±0·7 Gy. V20 for the lung increased in most patients; the median increase was 1·6%. The dose to the spinal cord was unaffected by intra-fractional motion. The dose to the heart was slightly reduced in most patients. The median reduction in the mean heart dose was 0·22 Gy, and V30 was reduced by 2·5%. The maximum dose to the oesophagus was also reduced in most patients, by 0·74 Gy, whereas V50 did not change significantly. The median number of points in which dose differences exceeded 3%/3 mm was 6·2%.

Intra-fractional anatomical changes reduce PTV coverage compared to the coverage predicted by clinical treatment planning systems that use the average CT for dose calculation. Doses to organs at risk were mostly over-predicted.

Lung tumours, especially those in the lower lobes, can move a lot during respiration; this motion needs to be accounted for during radiotherapy. In cases where 4D CT simulation scans are not performed, the current protocol at our centre is to apply a generic (internal motion + setup) margin of 0·70 cm in the axial plane and 1·20 cm in the longitudinal plane to all lung tumours, regardless of location. We analyse the tumour motions of a cohort of our local patients and categorise them into different locations in the lung. We seek to assess the adequacy of the current margins and to derive a more accurate set of standard margins which are specific for lung tumour locations.

All cases of lung tumours treated with stereotactic ablative radiotherapy between 2012 and 2016 were identified retrospectively and 4D CT scan data analysed. These tumours were grouped into the following locations: upper zone (UZ), middle zone (MZ) and lower zone (LZ). The treatment planning system was used to generate the displacements of the centre of mass of the tumours in the right–left, anterior–posterior and superior–inferior axes; these were compared with the current generic margins. Median displacements were calculated for each axis in each location. New planning target volume (PTV) margins were derived by summing the median displacement, median absolute deviation (MAD) and 0·5 cm (for setup error).

Sixty-three cases were eligible for analyses. Motion in the superior–inferior direction was the greatest for all tumour locations, ranging from a median of 0·17 cm (MAD 0·12 cm) in UZ to 0·77 cm (MAD 0·27 cm) in LZ. Median tumour displacements in the anterior–posterior and right–left axes were similar for all locations, <0·30 and 0·20 cm, respectively. The current generic margins were adequate for only one-third of the cases in this study. A new PTV margin of 2·10 cm in the superior–inferior axis may be required for LZ tumours, while an additional 1–2 mm should be added to the current radial margins.

The current generic margins are inadequate for the majority of cases. Tumour motion is the greatest in LZ in the superior–inferior axis. Motion mitigation strategies are essential for large LZ tumours.

To evaluate efficacy of helical tomotherapy (HT) for treatment of breast cancer with internal mammary lymph node involvement.

This is a retrospective clinical audit of planning, dosimetry, toxicity and short-term survival of a cohort of 65 patients. Patients were treated between November 2014 and May 2019. The primary and nodal region was prescribed a dose of 50 Gray (Gy) in 25 fractions, while all cases of breast conserving surgery received a simultaneous integrated boost to a dose of 61 Gy in 25 fractions.

The 95% coverage for the primary, supraclavicular, internal mammary node and tumour bed was 93·4%, 96·8%, 90·7% and 98·3%, respectively. Mean dose to total lung, heart and contra-lateral breast was 10·6 Gy, 6·92 Gy and 4·32 Gy, respectively. None developed grade III skin or oesophageal toxicity. Twenty-one patients had progression; of which eighteen developed only distant failure while three also had loco-regional recurrence. At a median follow-up of 36 months, the 3-year loco-regional control, disease-free survival and overall survival were 93·5, 73·9 and 85·9%, respectively.

We report encouraging clinical outcome for patients treated uniformly with HT. The predominant pattern of failure was distant metastases which suggests the need for systemic control intensification.

In thoracic radiotherapy (RT), heart sparing is very essential, as the high cardiac dose is associated with poor survival in patients with locally advanced non-small-cell lung cancer (NSCLC). The study aims to determine the doses exposed to heart substructures and coronary arteries by different RT techniques in central tumor irradiation in lung cancer.

Twenty patients with NSCLC, irradiated between January 2018 and December 2020 in our department, were included in this study. Patients whose primary tumor was centrally located in the left lung were selected. The heart substructures [left atrium, right atrium (RA), left ventricle, and right ventricle] and coronary arteries (left main, left anterior descending, circumflex, and right coronary arteries) were delineated by the same physician. The doses of 60 Gy external RT were prescribed in 30 fractions using three-dimensional conformal radiotherapy (3D-CRT), static intensity-modulated radiotherapy (s-IMRT), and dynamic intensity-modulated radiotherapy (d-IMRT) techniques in all patients. The obtaining plans using three different techniques were compared.

The d-IMRT plans were statistically the best optimal plan for planning target volume (PTV) [Dmean (p = 0 04), Dmax (p < 0 0001), V95 (p < 0 0001), V107 (p < 0 0001), CI (p < 0 0001) and HI (p < 0 0001)]. The s-IMRT plans were significantly superior to 3D-CRT plans for PTV. RA Dmax and V45 were not different between the three techniques [Dmax (p = 0 148) and V45 (p = 0 12)]. The d-IMRT technique was significantly better in other heart substructures and coronary arteries.

Compared to 3D-CRT and s-IMRT techniques, the d-IMRT technique provided the best protection in all heart substructures except for a few parameters (RA Dmax and V45 doses).

This work reports on the normal tissue complication probabilities (NTCP) from a UK cohort of previously treated peripheral lung SABR patients (n = 198) supplementing our previous publication on tumour control probabilities (TCP). Each patient was recalculated for alternative schedules.

NTCP for 3 (54 Gy), 5 (55 and 60 Gy) and 8 (50 Gy) fraction (#) schemes were calculated with the Lyman Kutcher Burman (LKB) model in the software platform ‘Biosuite’ (Version 12·01) for lung and chest wall. Patients treated with 5 # or 8 # were then recomputed for alternative fractionations and doses (3 # and 5 #, for both 55 Gy and 60 Gy).

The mean lung NTCP (NTCPLUNG, for the outcome of radiation pneumonitis) was 2·8% (range 0·6 – 10·6). The mean chest wall NTCP (NTCPCW, for the outcome of rib fracture) was 1·4% (range 0·0–55·9). There were no statistically significant differences observed between male and female, tumour status or fractionation groups except for the NTCPLUNG between 5 # and 3 #. When recalculating NTCP and TCP individually, for 8 # patients, no differences were observed between mean TCP, NTCPLUNG or NTCPCW compared with 3 # or 5 # indicating that fractionation reduction is possible. Parity was observed between the 60 Gy group when recalculated for 55 Gy. For the 60 Gy in 5 # group, the NTCPCW increased significantly when recalculated for 3 #.

NTCPs achievable with current UK planning techniques have been presented indicating SABR Consortium compliant centres are likely to have low complication population risks (< 3 %). 5 # schedules could be justified for 8 # patients, thereby reducing the number of treatment visits. Where there is a large overlap of PTV and chest wall, this indicates an NTCP/TCP calculation is required to investigate if fractionation reduction is individually appropriate.

The purpose of the study was to evaluate the impact of changes in breathing pattern inside the breath-hold window (BHW) during deep inspiration breath hold treatment for carcinoma left breast patients post-conservative surgery.

Ten patients of carcinoma left breast post-conservative surgery were prospectively selected. Three sets of CT plain images were acquired, one with 5 mm deep inspiration BHW (DIBHR) and the other one with 1 mm BHW matching the lower threshold (DIBHL) and the third one with 1 mm BHW matching the upper threshold (DIBHH) as DIBHR. For all patients, forward intensity-modulated radiotherapy (FIMRT) and volumetric modulated arc therapy (VMAT) plans were generated in the 5 mm BHW CT series and the same plan being copy and pasted in other series. Target volume doses and critical structure doses were tabulated.

Planning target volume coverage was adequate and no significant differences were found in any CT series. Significant differences noted in average left lung V5%, V10% and V18% doses between DIBHR versus DIBHH (p values = 0·0461, 0·0283 and 0·0213, respectively) and DIBHL versus DIBHH (p values = 0·0434, 0·0484 and 0·0334, respectively) for FIMRT plans and V18% doses in DIBHR versus DIBHH (p = 0·0067) in VMAT. No differences in heart and apex of heart doses were found. Left anterior descending artery (LAD) mean doses were significant in DIBHL versus DIBHR, DIBHR versus DIBHH and DIBHL versus DIBHH (p = 0·0012, 0·0444 and 0·0048, respectively) series for FIMRT plans and DIBHR versus DIBHH and DIBHL versus DIBHH (p = 0·0341, 0·0001) for VMAT plans.

The changes in the breathing pattern inside DIBH window level cause some variation in LAD doses and no other significant differences in any parameters noted, so care should be taken while treating patients with preexisting cardiac conditions.

A middle-aged gentleman presenting with dyspnoea was presumptively assumed to be a novel coronavirus suspect.

Nasopharyngeal and oropharyngeal swabs were reported negative, and clinico-radiological workup revealed a case of adenoid cystic carcinoma (ACC) of the lung with metastases to the contralateral lung and the lumbar vertebrae.

ACC is a rare malignancy of exocrine glands. Most commonly found in the minor salivary glands, they may rarely occur in other sites. Primary ACC of the lung is a rare histologic subtype that is encountered infrequently in clinical practice for which standard guidelines do not exist.

Evaluating the improvements of placing the treatment isocentre at the boost centre of mass (CoM) in a hybrid treatment for breast cancer radiotherapy.

Twenty-two patients were planned in two isocentre locations with two forward intensity-modulated radiation therapy (fIMRT) tangentials to the breast and a volumetric-modulated arc therapy (VMAT) to the boost. A simultaneous integrated boost technique was used. Breast Boost (BB) Vector was investigated as a criterion for selecting an appropriate isocentre placement. Various metrics for boost, breast and hybrid plans were analysed using analysis of variance statistics.

Comparing hybrid plans at the boost CoM vs. hybrid plans at the breast CoM, no significant differences were found. Analysis of relative variations of planning target volume (PTV) boost coverage vs. BB Vector indicated an upgrade in boost CoM isocentre strategy. Dose to organs at risk was comparable: V5Gy (26·24 vs. 25·69%, p = 0·8), V20Gy (14·66 vs. 14·58%, p = 0·959) and the mean dose (7·37 Gy vs. 7·26 Gy, p = 0·879) to ipsilateral lung; V5Gy (15·60 vs. 15·22%, p = 0·903), and the mean dose (4·91 Gy vs. 4·86 Gy, p = 0·950) to heart and dose to free breast of boost (46·71 Gy vs. 46·62 Gy, p = 0·408).

The hybrid fIMRT–VMAT technique centred at the boost CoM resulted equivalent to plans centred at the breast CoM, while benefiting from an enhancement in PTV boost coverage for patients with BB Vector superior to 5.

Lung cancer is the most commonly diagnosed cancer in Canada and the leading cause of cancer-related mortality in both men and women in North America. Surgery is usually the primary treatment option for early-stage non-small cell lung cancer (NSCLC). However, for patients who may not be suitable candidates for surgery, stereotactic body radiation therapy (SBRT) is an alternative method of treatment. SBRT has proven to be an effective technique for treating NSCLC patients by focally administering high radiation dose to the tumour with acceptable risk of toxicity to surrounding healthy tissues. The goal of this comprehensive retrospective dosimetric study is to compare the dosimetric parameters between three-dimensional conformal radiation therapy (3DCRT) and volumetric-modulated arc therapy (VMAT) lung SBRT treatment plans for two prescription doses.

We retrospectively analysed and compared lung SBRT treatment plans of 263 patients treated with either a 3DCRT non-coplanar or with 2–3 VMAT arcs technique at 48 Gy in 4 fractions (48 Gy/4) or 50 Gy in 5 fractions (50 Gy/5) prescribed to the planning target volume (PTV), typically encompassing the 80% isodose volume. All patients were treated on either a Varian 21EX or TrueBeam linear accelerator using 6-MV or 10-MV photon beams.

The mean PTV V95% and V100% for treatment plans at 48 Gy/4 are 99·4 ± 0·6% and 96·0 ± 1·0%, respectively, for 3DCRT and 99·7 ± 0·4% and 96·4 ± 3·4%, respectively, for VMAT. The corresponding mean PTV V95% and V100% at 50 Gy/5 are 99·0 ± 1·4% and 95·5 ± 2·5% for 3DCRT and 99·5 ± 0·8% and 96·1 ± 1·6% for VMAT. The CIRI and HI5/95 for the PTV at 48 Gy/4 are 1·1 ± 0·1 and 1·2 ± 0·0 for 3DCRT and 1·0 ± 0·1 and 1·2 ± 0·0 for VMAT. The corresponding CIRI and HI5/95 at 50 Gy/5 are 1·1 ± 0·1 and 1·3 ± 0·1 for 3DCRT and 1·0 ± 0·1 and 1·2 ± 0·0 for VMAT. The mean R50% and D2cm at 48 Gy/4 are 5·0 ± 0·8 and 61·2 ± 7·0% for 3DCRT and 4·9 ± 0·8 and 57·8 ± 7·9% for VMAT. The corresponding R50% and D2cm at 50 Gy/5 are 4·7 ± 0·5 and 65·5 ± 9·4% for 3DCRT and 4·7 ± 0·7 and 60·0 ± 7·2% for VMAT.

The use of 3DCRT or VMAT technique for lung SBRT is an efficient and reliable method for achieving dose conformity, rapid dose fall-off and minimising doses to the organs at risk. The VMAT technique resulted in improved dose conformity, rapid dose fall-off from the PTV compared to 3DCRT, although the magnitude may not be clinically significant.

The aim of this work is to report on the tumour control probability (TCP) of a UK cohort of lung stereotactic ablative radiotherapy patients (n = 198) for a range of dose and fractionations common in the UK.

TCP values for 3 (54 Gy), 5 (55 and 60 Gy) and 8 (50 Gy) fraction (#) schemes were calculated with the linear-quadratic Marsden TCP model using the Biosuite software.

TCP values of 100% were computed for the 3 # and for 5 # (α/β = 10 Gy) cohorts; reduced to 99% (range 97–100) for the 5 # cohort only when an α/β of 20 Gy was used. The average TCP value for the 50 Gy in 8 # regime was 97% (range 92–99, α/β = 10 Gy) and 64% (range 48–79, α/β = 20 Gy). Statistical significant differences were observed between the α/β of 10 Gy versus 20 Gy groups and between all data grouped by fraction.

TCPs achievable with current planning techniques in the UK have been presented. The ultra-conservative 50 Gy in 8 # scheme returns a significantly lower TCP than the other regimes.

The purpose of the present study is to compare hybrid [three-dimensional conformal radiation therapy-volumetric-modulated arc therapy (3DCRT-VMAT)] and helical tomotherapy (HT) techniques in terms of both planning target volume (PTV) and organs at risk (OARs) in the plans we made in locally advanced non-small cell lung cancer (NSCLC) patients

Radiotherapy was planned for 15 locally advanced NSCLC patients with 2 different techniques. Large tumours with positive mediastinal lymph nodes were preferred. The prescription dose was determined as 60 Gy at 30 fractions.

Mean PTV volume was 602·5 cc (range: 265–1461). Mean total lung volume was 4264 cc (range: 1885–6803). Homogeneity index, Dmean, Dmax, D2 and V105 were found to be lower in HT, V100, total monitor units (MU) and total beam on time were found to be lower in the hybrid plan. Total lung Dmean was found to be 17 Gy in both techniques. V10 value was 42·85 in the hybrid plan and 48·67 in HT (p = 0·037). Heart Dmean was 14·5 Gy in the hybrid plan and 18·7 in HT (p < 0·001), and V30 values were 18·1 and 22·9, respectively (p = 0·009).

Suitable dose coverage and OAR doses can be provided with both techniques. Especially the opposite lung, heart and oesophagus doses can be kept lower with the hybrid plan, and lower MU and shorter beam on time can be provided.

CyberKnife is the most advanced form of stereotactic body radiotherapy (SBRT) system that uses a robotic arm to deliver highly focused beams of radiation; however, a limitation is that it only irradiates from ceiling to floor direction. In patients with posterior lungs tumour who are positioned supine, normal lung tissue may suffer undesirable radiation injuries. This study compares the treatment planning between the prone set-up and the supine set-up for lung cancer in CyberKnife SBRT to decrease normal lung dose to avoid radiation side effects.

A human phantom was used to generate 108 plans (54 for prone and 54 for supine) using the CyberKnife planning platform. The supine and prone plans were compared in terms of the dosimetric characteristics, delivery efficiency and plan efficiency.

For posterior targets, the area of low-dose exposure to normal lungs was smaller in the prone set-up than in the supine set-up. V10 of the lungs was 7·53% and 10·47% (p < 0·001) in the anterior region, and 10·78% and 8·03% (p < 0·001) in the posterior region in the supine and prone set-up plans, respectively.

The comparison between the prone set-up and the supine set-up was investigated with regard to target coverage and dose to organs at risk. Our results may be deployed in CyberKnife treatment planning to monitor normal tissue dose by considering patient positioning. This may assist in the design of better treatment plans and prevention of symptomatic radiation pneumonitis in lung cancer patients.

Stereotactic body radiation therapy for lung tumours can expose patients to radiation pneumonitis (RP) (<6 months after irradiation) and lung fibrosis (beyond 6 months). The aim of this study was to describe post-irradiation radiographics appearances.

This retrospective study of 90 patients with a stage I non-small cell lung carcinoma reports a detailed description of the computed tomography (CT) or positron emission tomography/CT changes that can be observed after treatment, according to modified Kimura score for RP and Koenig’s classification for fibrosis. This evaluation was realised at 1 month and then every 3–4 months, with a median follow-up of 35 months.

The most common radiological RP pattern was diffuse consolidation. It appears in a mean time of 4 months and reaches its maximum at 9 months after radiotherapy. Seventy-three per cent of the RP evolved to fibrosis. Most of these findings were encompassed in the 35 Gy isodose.

Radiological parenchymal changes are frequent in the treatment region, which renders the tumour response monitoring by tumour size, particularly by response evaluation criteria in solid tumours, unsuitable.

Lung cancer has a high mortality rate mainly due to the lack of early detection or outward signs and symptoms, thereby often progressing to advanced stages (e.g., stage IV) before it is diagnosed. However, if lung cancers can be diagnosed at an early stage and also if clinicians can prospectively identify patients likely to respond to specific treatments, then there is a very high potential to increase patients’ survival. In recent years, several investigations have been conducted to identify cancer biomarkers for lung cancer risk assessment, early detection and diagnosis, the likelihood of identifying the group of patients who will benefit from a particular treatment and monitoring patient response to treatment.

This paper reports on the review of 19 current clinical and emerging biomarkers used in risk assessment, screening for early detection and diagnosis and monitoring the response of treatment of non-small-cell lung cancers.

The future holds promise for personalised and targeted medicine from prevention, diagnosis to treatment, which take into account individual patient’s variability, though it depends on the development of effective biomarkers interrogating the key aberrant pathways and potentially targetable with molecular targeted or immunologic therapies. Lung cancer biomarkers have the potential to guide clinical decision-making since they can potentially detect the disease early, measure the risk of developing the disease and the risk of progression, provide accurate information of patient response to a specific treatment and are capable of informing clinicians about the likely outcome of a cancer diagnosis independent of the treatment received. Moreover, lung cancer biomarkers are increasingly linked to specific molecular pathway deregulations and/or cancer pathogenesis and can be used to justify the application of certain therapeutic or interventional strategies.

This work compares dose-volume constraints (DVCs) and tumour control predictions based on the average intensity projection (AVIP) to those on each phase of the four-dimensional computed tomography.

In this prospective study plans generated on an AVIP for nine patients with locally advanced non-small-cell lung cancer were recalculated on each phase. Dose-volume histogram (DVH) metrics extracted and tumour control probabilities (TCP) were calculated. These were evaluated by Bland–Altman analysis and Pearson Correlation.

The largest difference between clinical target volume (CTV) on the individual phases and the internal CTV (iCTV) on the AVIP was seen for the smallest volume. For the planning target volume, the mean of each metric across all phases is well represented by the AVIP value. For most patients, TCPs from individual phases are representative of that on the AVIP. Organ at risk metrics from the AVIP are similar to those seen across all phases.

Utilising traditional DVH metrics on an AVIP is generally valid, however, additional investigation may be required for small target volumes in combination with large motion as the differences between the values on the AVIP and any given phase may be significant.

To identify treatment outcome, dose uniformity, treatment time, toxicity among 3D conformal therapy (3D-CRT), intensity-modulated radiation therapy (IMRT), volumetric-modulated arc therapy (VMAT) for non-small-cell lung cancer (NSCLC) based on literature review.

A literature search was conducted using PubMed/MEDLINE, BMC—part of Springer Nature, Google Scholar and iMEDPub Ltd with the following keywords for filtering: 3D-CRT, IMRT, VMAT, lung cancer, local control and radiobiology. A total of 14 publications were finally selected for the comparison of 3D-CRT, IMRT and VMAT to determine which technique is superior or inferior among these three.

Compared to 3D-CRT, IMRT delivers more precise treatment, has better conformal dose coverage to planning target volume (PTV) that covers gross tumour with microscopic extension, respiratory tumour motion and setup margin. 3D-CRT has large number of limitations: low overall survival (OS), large toxicity, secondary malignancies.

It is difficult to choose the best technique for treating NSCLC due to patient conditions and technique availability. A high-precision treatment may improve tumour control probability (TCP) and patient’s quality of life. VMAT, whether superior or not, needs more clinical trials to treat NSCLC and requires longer dose optimisation time with the greatest benefit of rapid treatment delivery, improved patient comfort, reduced intrafraction motion and increased patient throughput compared to IMRT and 3D-CRT.

The aim of this study was to investigate the extent to which lung stereotactic body radiotherapy (SBRT) treatment plans can be improved by replacing conventional flattening filter (FF) beams with flattening filter-free (FFF) beams.

We selected 15 patients who had received SBRT with conventional 6-MV photon beams for early-stage lung cancer. We imported the patients’ treatment plans into the Eclipse 13·6 treatment planning system, in which we configured the AAA dose calculation model using representative beam data for a TrueBeam accelerator operated in 6-MV FFF mode. We then created new treatment plans by replacing the conventional FF beams in the original plans with FFF beams.

The FFF plans had better target coverage than the original FF plans did. For the planning target volume, FFF plans significantly improved the D98, D95, D90, homogeneity index and uncomplicated tumour control probability. In most cases, the doses to organs at risk were lower in FFF plans. FFF plans significantly reduced the mean lung dose, V10, V20, V30, and normal tissue complication probability for the total lung and improved the dosimetric indices for the ipsilateral lung. For most patients, FFF beams achieved lower maximum doses to the oesophagus, heart and the spinal cord, and a lower chest wall V30.

Compared with FF beams, FFF beams achieved lower doses to organs at risk, especially the lung, without compromising tumour coverage; in fact, FFF beams improved coverage in most cases. Thus, replacing FF beams with FFF beams can achieve a better therapeutic ratio.

To determine whether myocardial perfusion scintigraphy (MPS) changes in lung cancer patients treated with radiotherapy (RT) were detectable with late gadolinium enhancement cardiac magnetic resonance imaging (LGE CMR).

Twenty-one patients with lung cancer were evaluated pre-RT and at 2 and 6 months post-RT follow-up (FU) with MPS and LGE CMR. MPS changes in the left ventricle (LV) were analysed using the semi-quantitative summed rest score method (20 segments) and the Bull’s-eye-view technique. The LGE CMR studies were analysed for visual signs of myocardial damage (fibrosis), that is, focal LGE in the LV and cardiac function parameters.

MPS changes were detected in 7/20 patients at 2 months FU and in 8/13 patients at 6 months FU. Only one patient had a new irreversible defect judged to be caused by direct irradiation. MPS changes in two cases were deemed to be caused by attenuation. All new MPS defects were minor and no corresponding myocardial damage, or any functional changes, were evident on LGE CMR.

The extent of MPS changes at 6 months FU appeared less prominent than in previous reports. No visual signs or functional changes corresponding to myocardial damage were detected on LGE CMR. A risk for false-positive MPS changes caused by attenuation is evident.