Nodal boost is being increasingly employed to escalate the dose to involved nodes in node-positive cervical cancer. The study aimed to compare the dosimetric differences between sequential boost intensity-modulated radiation therapy (SeB-IMRT) and simultaneous integrated boost IMRT (SIB-IMRT) in terms of target coverage and organs-at-risk (OARs) with special emphasis on the effect of nodal shrinkage and anatomical change of normal tissues during radiotherapy.

Two computed tomography (CT) datasets (of phase I and phase II) of 40 patients of node-positive cervical cancer treated with SeB-IMRT [planning target volume (PTV) 45/25] followed by SeB to residual nodes (PTV 12·6/7) were utilised. SIB-IMRT1 plan consisted of PTV pelvis and para-aortic nodal region (PTV 45/25) and SIB to gross nodes (PTV 55/25). In order to account for the change in nodal and normal tissue topography during treatment, a third plan (SIB-IMRT2) was generated by utilising the SIB-IMRT1 plan for 44 Gy in 20 fractions and reproducing the plan on the second CT dataset for 11 Gy in 5 fractions. Dosimetric parameters of the three plans were compared using the Friedman test with Bonferroni correction.

We observed that the doses to OARs (bowel, rectum and bladder) were significantly higher in SeB-IMRT plan as compared to the SIB-IMRT plans. V40 Gy of bowel for SeB-IMRT, SIB-IMRT1 and SIB-IMRT2 plans were 354·8 cc, 271 cc and 321·8 cc, respectively (p = 0·001), whereas V30 Gy were 687·8 cc, 635·5 cc and 680 cc, respectively (p = 0·001). The target coverage was marginally better in SeB-IMRT plan as compared to SIB-IMRT1 and SIB-IMRT2 plans (V95% = 99·2 versus 97·7 versus 97·9, respectively, p = 0·000)

SIB-IMRT led to better sparing of OARs, especially bowel. However, the magnitude of benefit decreases if the change in nodal and normal tissue topography during radiotherapy is not considered implying the need for frequent image guidance when SIB-IMRT is planned for node-positive cervical cancer.

To compare the acute radiation-induced bowel and bladder toxicities of two hypofractionated radiotherapy (HFRT) regimens in localised prostate cancer (PCa).

This trial consists of patients with histologically confirmed stage T1-T3aN0M0 PCa, a prostate-specific antigen concentration of 40 ng/mL or lower, and Eastern Cooperative Oncology Group performance status of 0–2. Participants were randomly assigned (1:1) to 56 Gy in 16 fractions over 4 weeks (arm A) or 70·2 Gy in 26 fractions over 5 weeks (arm B). Acute bowel and bladder toxicities were assessed using Radiation Therapy Oncology Group criteria.

Between June 2018 and December 2019, 40 patients were randomly assigned to treatment with 4-week (n = 20) and 5-week HFRT (n = 20). In the third month after completion of radiotherapy, the cumulative incidence of acute bowel and bladder toxicities of arms A and B was 20 versus 5% and 70 versus 85%, respectively. The cumulative incidence of grade 2 or worse bowel and bladder toxicities of the 5-week regimen was non-inferior to 4-week HFRT [bowel toxicity: 5% (arm A) versus 5% (arm B), bladder toxicity: 50% (arm A) versus 60% (arm B), p = 0·52).

The 5-week regimen of HFRT is non-inferior to 4-week HFRT in terms of acute bowel and bladder toxicities.

To evaluate the efficacy of concurrent chemotherapy and high-dose (≥55 Gy) intensity-modulated radiotherapy (CCIMRT) in comparison with chemotherapy alone and intensity-modulated radiotherapy (IMRT) alone for unresectable locally advanced or metastatic pancreatic cancer.

Forty-six patients with pancreatic cancer undergoing CCIMRT (n = 17), chemotherapy alone (n = 16) or IMRT alone (n = 13) were analysed. Overall survival (OS), locoregional progression-free survival (LRPFS) and gastrointestinal toxicities were evaluated. The median radiation dose was 60 Gy (range, 55–60) delivered in a median of 25 fractions (range, 24–30). Gemcitabine (GEM) alone, GEM + S-1, S-1 alone, FOLFIRINOX and GEM + nab-paclitaxel were used in CCIMRT and chemo-monotherapy.

The 1-year OS rate was 69% in the CCIMRT group, 27% in the chemotherapy group and 38% in the IMRT group (p = 0·12). The 1-year LRPFS rate was 73, 0 and 40% in the 3 groups, respectively (p = 0·012). Acute Grade ≥ 2 gastrointestinal toxicity (nausea, diarrhea) was observed in 12% (2/17) in the CCIMRT group, 25% (4/16) in the chemotherapy group and 7·7% (1/13) in the IMRT group (p = 0·38). Late Grade 3 gastrointestinal bleeding was observed in 6·3% (1/16) in the chemotherapy group.

High-dose CCIMRT yielded acceptable toxicity and favorable OS and LRPFS.

The aim of this study was to find the optimal radiotherapy (RT) method using three-dimensional (3D) conformal RT (CRT), physical wedge-based CRT (WB-CRT) and dynamic intensity-modulated RT (D-IMRT) techniques for stomach cancer.

Ten patients with gastric cancer were selected for this study. For each patient, three different treatment plans were generated. 3D-CRT, WB-CRT and IMRT plans were evaluated in terms of dosimetry. Treatment plans were compared with respect to the planning target volume and organs at risk (OARs) volumes including right and left kidney doses (V13, V20 and V28), heart mean and maximum doses, spinal cord maximum doses, dose homogeneity index, conformity index (CI), delivery time and the monitor unit counts for the treatment. Statistical analysis was performed using the SPSS (Statistical Package for the Social Sciences) v25.1 software (IBM Inc., Chicago, IL, USA).

In stomach plans, IMRT showed a significantly lower dose for the left and right kidneys than that of WB-CRT or 3D-CRT (p < 0·05). Compared with WB-CRT or 3D-CRT, IMRT reduced the V28, V20, V13 and mean dose to bilateral kidneys (p < 0·05). IMRT plans indicated better dosimetry for at the Dmean of the liver and heart. Concerning the calculated CI, values for IMRT plans gave significant results than other plans (p < 0·05).

IMRT plans provided better protection for the kidneys, liver, heart and spinal cord. For the treatment of stomach cancer, considering the dose to the OARs, IMRT appears to be the most superior technique.

Comparison of the integral dose (ID) delivered to organs at risk (OAR), non-target body and target body by using different techniques of craniospinal irradiation (CSI).

Ten CSI patients (medulloblastoma) already planned and treated either with linear accelerator three-dimensional conformal radiation therapy (Linac-3DCRT) technique or with linear accelerator RapidArc (Linac-RapidArc) technique by Novalis-Tx Linac machine have been analysed. Retrospectively, these patients are again planned on Radixact-X9 Linac with Helical, Direct-3DCRT and Direct-intensity-modulated radiation therapy (Direct-IMRT) techniques. The dose prescription to planning target volume brain (PTV-Brain) and PTV-Spine is 36 Gy in 20 fractions and is kept the same for all techniques. The target body, non-target body, OARs and total body dose are compared.

ID is lowest in the RapidArc plan for every patient in comparison to Helical and Direct-IMRT. The ID for Body-PTV was found slightly higher in the RapidArc plan in comparison to 3DCRT plans. But there is better normal tissue sparing for most of the OARs in RapidArc plans if it compares with 3DCRT plans.

RapidArc is a better alternative for the treatment of CSI. It provides better target coverage and better OARs sparing from any other treatment techniques.

A comparative study was performed about the plan parameters and quality indices between volumetric arc therapy (VMAT) and intensity-modulated radiotherapy (IMRT) for the treatment of high-risk prostate cancer patients. The aim of this retrospective study was to compare the two methods of external beam radiotherapy IMRT and VMAT in terms of plan quality and efficacy.

Fifteen high-risk prostate patients were planned for radiotherapy using 6 MV photon. Three dose levels were contoured having Planning Tumour Volume 1 (PTV1 = 48 Gy), Planning Tumour Volume 2 (PTV2 = 57.6 Gy) and Planning Tumour Volume 3 (PTV3 = 60 Gy). Setup margins were given using the CHIP trial method. The prescribed PTV3 dose was 60 Gy in 20 fractions which is biologically equivalent to 74 Gy in 37 fractions using α/β = 3. In case of IMRT, seven fixed beam angles 30, 60, 105, 180, 255, 300 and 330 were used and the dose was optimised using the sliding window method. In case of rapid arc technique, one or two full arcs were used for dose optimisation while keeping all the dose constraints and other planning parameters same used in IMRT. The plan evaluation parameters and Organ at risks (OARs) doses were calculated using a dose volume histogram (DVH).

The average D2, D5, D95 and PTVmean for PTV3 were 61.22, 61.13, 58.12, 60.00 Gy and 62.41 62.24 59.53 61.12 Gy for IMRT and VMAT, respectively. The averages V60 for bladder and V30 for rectum were 22.81, 25 and 67, 65% for IMRT and VMAT, respectively. The average homogeneity index (HI), conformity index (CI) and gradient index (GI) were 1.04, 1.4833, 14.79 and 1.04, 1.704, 7.89 for IMRT and VMAT, respectively.

VMAT takes less dose-delivery time and lesser number of monitoring units than IMRT, thus it compensates the intrafractional movements during dose delivery. The Dose GI in VMAT was much better than IMRT. This indicates sharper dose fall off near the normal tissue. No other major differences were observed in terms of plan evaluation parameters between IMRT and VMAT techniques. So, we conclude that VMAT technique is more efficient than IMRT in terms of plan quality and dose delivery.

Radiotherapy is an option to treat high-grade laryngeal dysplasia. This study aimed to evaluate the use of intensity-modulated radiotherapy, 55 Gy in 20 daily fractions, in treating this disease.

Acute toxicity was evaluated in all 14 patients treated. In 10 patients, functional voice outcome was measured using the Voice Handicap Index, and the Grade, Roughness, Breath, Asthenia, Strain (‘GRBAS’) scale. These measurements were performed pre-treatment and three months after intensity-modulated radiotherapy.

All but one patient managed to complete radiotherapy. Acute toxicity was significant (one patient developed grade 4 and three patients developed grade 3 dysphagia). Four patients required hospital admission. In 9 out of 10 patients, radiotherapy improved voice quality.

This radiotherapy regimen using intensity-modulated radiotherapy for laryngeal dysplasia is feasible and provided excellent functional outcome, but acute toxicity was significant. Dose de-escalation can be considered in the framework of clinical trials.

This study is primarily aimed at the analysis of various dose homogeneity indices (HIs) essential for the evaluation of therapeutic plans by employing intensity-modulated radiation therapy (IMRT) on patients with cervix cancer. Also integral dose (ID) to healthy surrounding organs is computed.

Effectiveness of different HIs (A, B, C, D) was explored for IMRT plans using 15 MV photon beam. In total, 18 patients were selected at random for treatment of cervix cancer, and dose of 5,040 cGy was delivered in 28 equal fractions.

The study was undertaken to compare four HI formulas and coefficient of determination between each set of HI was known by calculating R2 value. Mean±SD of HI A, HI B, HI C and HI D were 1·12±0·02, 0·13±0·04, 0·10±0·02 and 0·99±0·03, respectively. Mean value of ID for rectum is 3·16 and for bladder is 10·3.

Our data suggested that HI calculated using four formulas provided good plan quality. The results advocate that all the studied HIs can be effectively used for assessment of uniformity inside the target volume. However, values of HI C were closest to ideal value as compared with other three formulas; hence, it is considered a better measure to compute homogeneity of dose within target volume. The ID gives satisfactory results for surrounding normal tissues such as rectum and bladder and significant critical tissue sparing was achieved by using IMRT technique.

This study compared the pattern of radiation induced parotid changes between conventional (ConRT) and intensity modulated radiotherapy (IMRT) in nasopharyngeal carcinoma patients.

56 adult NPC patients treated with IMRT (n=28) and conventional radiotherapy (n=28) were recruited. CT scans were acquired before radiotherapy, at 10th, 20th and 30th fractions, and 3 months after treatment. Parotid gland was delineated in the corresponding CT slices and its mean dose was calculated. The volumetric and geometric changes of the parotid gland at various time intervals were compared against the pre-treatment structure set. The pattern of changes was compared between the two techniques.

The mean parotid dose of IMRT (37.5±9.5 Gy) was significantly lower than ConRT (49.1±7.4 Gy). The parotid gland volume, DICE similarity coefficient and lateral dimension of patient head gradually decreased during the radiotherapy course and partially recovered in 3 months post-treatment. The differences between two groups were not significant until at 3 month after treatment, where IMRT showed significantly better volume recovery.

Similar parotid gland size and location changes were observed during the treatment course in both ConRT and IMRT. However IMRT demonstrated better parotid volume recovery after treatment.

Advances in treatment over recent years have increased the long-term survival of young, female cancer patients; unfortunately these treatments bring a significant risk of ovarian failure and infertility. This literature review aimed to determine the optimal technique for ovarian preservation in pre-menopausal women receiving pelvic radiotherapy (IMRT). The traditional method comprises surgical transposition; IMRT and other emerging techniques may offer alternative non-invasive means of sparing ovaries and minimising dose.

A critical review of the evidence pertaining to pelvic radiotherapy and ovarian sparing was performed. Evidence was subjected to critical appraisal using the Critical Appraisal Skills Programme tool and thematic analysis of the findings identified key issues.

Surgical transposition appears to be a successful method of preserving ovarian function depending on the position of the ovaries outside of the radiation field, the age of the patient and the total dose received by the ovaries. There is limited modern evidence concerning its usage in relation to emerging techniques and technology. The use of IMRT is certainly widespread in the treatment of female pelvic cancers, however, there is no evidence supporting its use for reduction of ovarian dose. Several other studies have attempted to demonstrate new techniques to preserve ovarian function, but no functional outcome measures have reinforced their results.

Ovarian transposition has a proven track record for preservation of ovarian function, but the potential value of IMRT as a viable alternative to date remains unexplored. New work should be encouraged to determine the potential value of IMRT as a non-surgical alternative.

For chest wall irradiation in breast cancer patients, three-dimensional conformal radiotherapy (3DCRT) and intensity-modulated radiotherapy (IMRT) have made tremendous changes in treatment delivery.

The purpose of this study is to compare the dosimetric parameters in IMRT and 3DCRT plans.

IMRT and 3DCRT plans were generated for 25 randomly selected postmastectomy breast cancer patients. The prescribed dose (PD) was 50 Gray (Gy) in 25 fractions (#) at the rate of 2 Gy/# with 5#/week. Dose volume histogram was evaluated for planning target volume (PTV) coverage and dose to organs at risk (OARs). All the dosimetric parameters were compared using unpaired student’s t-test.

PTV coverage was significantly better in IMRT, although the 90% of PTV was well covered by 90% of PD in all plans by both the techniques. Homogeneity index and conformity index were better in IMRT. V5 Gy and Dmean of contralateral lung, contralateral breast and heart (right side chest wall cases) were found to be lesser in 3DCRT compared with that in IMRT. However, there was no significant difference in V20 Gy of ipsilateral lung and V25 Gy of heart (left side chest wall cases) in all the plans by both the techniques.

Adequate target coverage was achieved by both the techniques, however, dose to OARs were lesser in 3DCRT plans as compared with that in IMRT plans. Thus, it can be concluded that 3DCRT is as efficient as IMRT for the chest wall irradiation.

Deep inspiratory breath hold (DIBH) during left-breast irradiation helps to minimise cardiac irradiation by physically separating the heart from the left breast. The dose to organs-at-risk in intensity-modulated radiotherapy (IMRT) and opposed tangent three-dimensional conformal radiotherapy (3DCRT) during DIBH in patients with left-sided breast cancer was compared.

A total of 20 consecutive patients with left-sided breast cancer had a computed tomography scan utilising DIBH. Mean volumes of the heart, left anterior descending coronary artery, total lung and right breast receiving 5–95% of the prescription dose were calculated.

Target volume homogeneity was improved with IMRT and average mean dose to target was higher for 3DCRT (51·03 Gy) compared with IMRT (50·47 Gy, p<0·01). The average mean dose to the heart was lower with 3DCRT (87 versus 77 cGy, p<0·01). The average mean dose to the contralateral breast was also lower with 3DCRT (19 versus 17 cGy, p<0·01). Less monitor units (MUs) were required with 3DCRT with an average difference of 225 MU/fraction (p<0·01).

Under DIBH, absolute differences between 3DCRT and IMRT were minimal. 3DCRT under DIBH provided excellent dosimetric results in most patients with left-sided breast cancer without the need for IMRT.

To develop a regime of care for patients with head and neck cancers undergoing intensity-modulated radiotherapy (IMRT), with the support of a health advisor (HA) and temporary access to the mouth care product Caphosol™.

A HA was temporarily employed to assess, monitor and refer patients as appropriate and ensure patients received and utilised supplies of Caphosol™. A retrospective audit was undertaken to provide a gap analysis of current service. The data were used to develop a pro forma for documenting assessments and monitoring lifestyle factors for IMRT patients. Assessments referrals and compliance, plus hospital admissions owing to treatment-related issues, were documented during the baseline audit and the temporary HA service and provision of Caphosol™.

The presence of a HA facilitated 100% compliance with appropriate assessments, referrals and adherence to treatment. The data suggests that the additional provision of Caphosol™ may have reduced levels of mucositis and associated pain.

It is recommended that a HA role be established within radiotherapy departments to facilitate lifestyle assessments, referrals and compliance with positive behaviour changes (e.g., stopping smoking). The use of Caphosol™ as a routine part of mouth care regime for IMRT patients also warrants further investigation.

Increasingly we are using a combination of surgery, chemotherapy and radiotherapy for treatment of gynaecological malignancies. Most studies in literature are concentrated on the concept of survival. There is minimal data examining the impact of these treatments on quality of life. Survival being a surrogate marker is an arbitrary end point and is of arguable significance if quality of life is not maintained. Long-term side effects of radiotherapy are debilitating and severely affect quality of life. Pelvic insufficiency fractures (PIF) are a known long-term side effect of radiotherapy. Intensity-modulated radiotherapy (IMRT) is being routinely used in the treatment of prostate and head and neck cancer. We postulated that use of IMRT in gynaecological cancers reduces the incidence of PIF.

We retrospectively reviewed 10 cases of PIF treated on standard treatment. We recalculated dose volume histograms based on IMRT protocols for patients with PIF.

We found that none of the patients received any radiation at the fracture site and the total radiation received to the sacrum was lower compared with the standard treatment protocols.

We conclude that the feasibility of IMRT in gynaecological cancers should be further evaluated and might be an useful tool in reducing the number of PIF.