This study compared the plan dosimetry between the intensity-modulated radiation therapy (IMRT) and field-in-field (FIF) technique for head-and-neck cancer using the Elekta Monaco treatment planning system (TPS).

A total of 20 head-and-neck cancer patients were selected in this study. IMRT and FIF plans for the patients were created on the Monaco TPS (ver. 5.11.02) using the 6-MV photon beam generated by the Elekta Synergy linear accelerator. The dose–volume histograms, maximum doses, minimum doses, mean doses of the target volumes and organs-at-risk (OARs), conformity index (CI), homogeneity index (HI) and monitor units (MUs) were determined for each IMRT and FIF plan. All IMRT plans passed the patient-specific quality assurance tests from the 2D diode array measurements (MatriXX Evolution System, IBA Dosimetry, Germany).

The results showed that the dose distribution to the target volumes of IMRT plans was better than FIF plans, while the dose (mean or max dose) to the OAR was significantly lower than FIF plan, respectively. IMRT and FIF resulted in planning target volume coverage with mean dose of 71·32 ± 0·76 and 73·12 ± 0·62 Gy, respectively, and HI values of 0·08 ± 0·01 (IMRT) and 0·19 ± 0·06 (FIF). The CI for IMRT was 0·98 ± 0·01 and FIF was 0·97 ± 0·01. For the spinal cord tolerance (maximum dose < 45 Gy), IMRT resulted in 39·85 ± 2·04 Gy compared to 41·37 ± 2·42 Gy for FIF. In addition, the mean doses to the parotid grand were 27·27 ± 7·48 and 48·68 ± 1·62 Gy for the IMRT and FIF plans, respectively. Significantly more MUs were required in IMRT plans than FIF plans (on average, 846 ± 100 MU in IMRT and 467 ± 41 MU in FIF).

It is concluded that the IMRT technique could provide a better plan dosimetry than the FIF technique for head-and-neck patients.

For patients with locally advanced laryngeal cancer, two main treatment options are either up-front surgery [total laryngectomy (TL)] followed by postoperative adjuvant radiation therapy (RT) or definitive concurrent chemoradiation (CCRT) with surgery retained as salvage. The objectives were to study the feasibility of CCRT using intensity-modulated radiation therapy (IMRT) in locally advanced laryngeal cancer with respect to response, toxicities, and quality of life (QoL) and comparison with other modality—TL with post-operative RT.

The records of 48 patients with locally advanced laryngeal cancer (T3/T4aN0-2), registered between years 2014 and 2017, treated with IMRT (definitive or adjuvant postoperative IMRT) were analysed from the hospital database. The patients received RT either as definitive CCRT or as adjuvant treatment after TL. RT in all patients was delivered with IMRT-SIB(simultaneous integrated boost) technique and concurrent chemotherapy with weekly cisplatin. The response was assessed at 12 weeks. Toxicities and QoL were assessed and compared between patients receiving definitive CCRT and adjuvant RT.

92·3% patients who received definitive CCRT achieved complete response. Toxicities were of low grade in patients receiving both definitive and adjuvant treatments. All the patients (except two partial responders of CCRT) remained disease-free at the last follow-up. At 2 years of follow-up of each patient—Global QoL, emotional and social functioning were better in definitive CCRT patients. Laryngectomy patients had more dyspnoea, insomnia and financial difficulties. Although the problems of dry mouth, sticky saliva and swallowing were comparable, laryngectomy patients faced more problems with speech, senses, social eating, social contact and cough.

Definitive CCRT using IMRT-SIB with weekly cisplatin is a feasible option for patients of locally advanced laryngeal cancer with acceptable response rate. IMRT yields better toxicity outcomes with sparing of organs at risk. CCRT patients have better QoL than laryngectomy patients in several parameters.

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.

Combined modality treatment regimens have provided modest gains in locoregional control rates of cancers of the head and neck (HNC), and intensity-modulated radiation therapy (IMRT) has gained widespread use. The methodology for determining contours of the gross tumour volume (GTV) in the radiation treatment plan is often based on combined anatomic and metabolic data from positron emission tomography–computed tomography (PET-CT). This study aimed to retrospectively evaluate the overall survival and disease-free survival outcomes of patients with HNC who received definitive IMRT with or without chemotherapy, planned with PET-CT.

A total of 1,200 patients underwent treatment for HNC during the study period, from 1 January 2002 to 31 December 2010. Of those, 261 cases had evaluable data that met the inclusion criteria for the study. The incidence and timing of locoregional recurrence, distant metastatic disease, new primary malignancies and death were evaluated retrospectively. Overall and disease-free survival (survival to time of first recurrence) were determined by the life table method. Incidence of distance metastatic disease and additional cancers were also studied.

Median follow-up from treatment initiation was 26·4 months (range 1·2–84·7 months). Overall survival and disease-free survival rates were 0·883 and 0·791, respectively, at 1 year; 0·793 and 0·688, respectively, at 2 years; and 0·732 and 0·619, respectively, at 3 years. The cumulative risk of recurrence was 22·6% at 3 years following definitive IMRT and the median time to recurrence was 345 days. There was an overall low incidence of distant metastatic disease (3·07%) and additional cancers (8·05%).

Overall and disease-free survival outcomes of a large cohort of HNC patients treated with definitive IMRT radiotherapy following treatment planning with PET-CT shows a similar high level of disease control and mortality rate as previously published outcome studies of shorter terms and/or smaller numbers of patients.