To propose a new matching method for the supraclavicular (SC) and tangential fields on three-dimensional radiotherapy (3DRT) for postmastectomy radiotherapy (PMRT).

A method of matching coplanar field borders (CFB) between the tangential and SC fields was created in 3DRT. The collimator angle of the medial tangential field was calculated to coplanar the SC field. The proposed method performance was ultimately benchmarked using the half beam block (HBB) and traditional three-field monoisocenter (TTM) methods by dosimetric comparison. The decision score was then employed to clarify the performance among these methods.

The results show that the TTM method exhibited not only low doses on the organs at risk (OAR) but also on the matching fields. The CFB and HBB produced comparable results, but the ipsilateral lung yielded lesser amounts than the HBB. The decision score indicated a low performance level when using the TTM method, whereas the CBF method exhibited a slightly higher performance score than the HBB.

The CFB exhibited good performance in terms of the dose on OARs and at the matching fields. This method offers a comparable level of performance to the HBB. Thus, the CFB offers an alternative method of significant interest in PMRT.

This study aimed to evaluate acute and late toxicities in nasopharyngeal cancer (NPC) patients who were treated between split-field (SF) and extended-field (EF) step-and-shoot intensity-modulated radiotherapy (IMRT) techniques.

Between January 2011 and October 2011, 21 NPC patients with stage I-IVB (7th edition American Joint Committee on Cancer Staging) were randomly assigned to undergo radiotherapy with SF or EF step-and-shoot IMRT technique.

At a median follow-up time of 60 months (range 3–77), we reported the comparable acute and late toxicities between the two techniques. One patient (9%) in SF-IMRT arm developed grade 3 acute skin toxicity.

Both SF and EF step-and-shoot IMRT techniques for NPC patients did not produce any statistically significant differences in both acute and late toxicities. Although no difference in toxicity was observed, technical problems due to field matching management were the obstacles in utilisation of SF-IMRT in our routine practice.

Radiotherapy is one of the treatments used to treat prostate cancer, and dose escalation to 74–78 Gy in conventional fractionation is the standard regimen. Currently, according to the hypothesis of low alpha/beta ratio in prostate cancer cells, using hypo-fractionation has been reported in many publications with promising results. This retrospective study was designed to evaluate the implementation of a moderate hypo-fractionation regimen in high-risk prostate cancer in our division.

Between 2012 and 2017, 40 patients with high-risk, localised prostate cancer were treated by a moderate hypo-fractionation regimen (70 Gy at 2·5 Gy per fraction) with intensity-modulated radiation therapy. The data related to treatment outcomes and toxicities were evaluated.

The mean PSA at diagnosis was 86·2 ng/mL (95% CI 49·9–122·4). Thirty-eight patients received long-term hormonal therapy. Fifty-two percent had a Gleason score of 8–10, and 65% had an initial PSA >20 ng/mL. The mean doses (in EQD2) to the D50% of PTV, D2% of organs at risk (bladder, rectum and bowels) were 80, 78·3, 76·4, and 50·2 Gy, respectively. Two patients had biochemical recurrence during the follow-up period.

A moderate hypo-fractionation regimen (70 Gy at 2·5 Gy per fraction) is feasible. Our experience found that this regimen yields tolerable, acceptable toxicity profiles in high-risk, localised prostate cancer patients.

Craniospinal irradiation (CSI) has become an important and challenging radiation technique for radiation oncologists. Helical tomotherapy (HT) seems to have dosimetric advantage for CSI compared with other radiation modalities. The purpose of this study was to compare dosimetric data between two different HT plans; simultaneous integrated boost (SIB) and sequential boost (Sq).

Twelve previously treated CSI contoured datasets by SIB technique were replanned. Dosimetric comparative parameters of targets were conformity index (CI) and homogeneity index (HI). For organ at risk (OARs), the mean dose of parallel organs, D2% of serial organs and whole body integral dose (ID) were also investigated.

SIB plan significantly provided more conformed dose to CSI and tumour boost while resulting in a similar CI in spinal boost region compared with Sq plan. The HI showed no differences between two plans. Radiation exposure to serial organs and ID were also significantly lower in SIB plan.

CSI treatment using HT, SIB technique was feasible and had more target coverage while minimising the radiation dose to healthy tissues.

To report of long-term results and toxicity profiles using image-guided brachytherapy (IGBT) combined with whole pelvic radiation therapy (WPRT) for cervical carcinoma.

In total, 52 patients with locally advanced cervical carcinoma were enrolled into the study. WPRT was used to treat the clinical target volume (CTV) with a dose of 45–50·4 Gy in 23–28 fractions. IGBT using computed tomography was performed at the dose of 6·5–7 Gy×4 fractions to the minimum dose covering 90% of target volume (D90) of high-risk clinical target volume (HR-CTV).

The mean cumulative dose in equivalent doses of 2 Gy for the D90 of HR-CTV, dose at 2% at refereed volume (D2cc) of bladder, D2cc of rectum and D2cc of sigmoid colon were 92·4, 87·9, 69·6, and 72 Gy, respectively. At the median follow-up time of 61 months, the 5-year local control, disease-free survival, and overall survival rates were 96·2, 75 and 84·6% respectively. Two patients (3·8%) developed grade 3–4 gastrointestinal and two patients (3·8%) developed grade 3–4 genitourinal toxicities.

The combination of WPRT plus IGBT showed very promising long-term results with excellent local control and toxicity profiles.

To compare intensity-modulated radiation therapy (IMRT) treatment planning between using positron emission tomography/computed tomography (PET/CT) and CT for target volume delineation in patients with non-small cell lung cancer (NSCLC).

Nine NSCLC patients with PET/CT images were enrolled into this study. Gross tumour volumes (GTVs) were delineated by the PET visual assessment (PETvis), the automated PET (PETauto), standardised uptake value (SUV)>2·5 (PET2·5) and threshold 40% SUVmax (PET40), and CT-based method. For each patient, two IMRT treatment plans based on CT and PET/CT delineation were performed. The target coverage and the dose–volume parameters for organs at risk were analysed.

The PETauto referred to PET40 when SUVmax<7 and PET2·5 when SUVmax≥7. The mean GTVs were 15·04, 15·7 and 15·14 cc for PETauto, PETvis and CT based, respectively. The GTV of PETauto was not different from PETvis (p=0·441) and CT based (p=0·594). Based on CT delineation in IMRT planning, only 34% of the cases had sufficient PET/CT planning target volumes coverage, whereas the organs at risk dose parameters were not statistically significant (p>0·05).

PET/CT enables more accurate assessment of tumour delineation for NSCLC, therefore improve target coverage in IMRT plan.