Prognostic triad: a novel method for decision-making for adjuvant treatment in stage I-II oral squamous cell carcinoma.

This study proposes a scoring system for adjuvant irradiation for stage I/II oral squamous cell carcinoma (OSCC). Derivation cohort (119 patients, operated between 2011 and 2014) and a validation cohort (204 patients, operated between 2016 and 2019) were included. In derivation cohort, on univariate analysis, tumor size >2 cm [3-year Disease Free Survival (DFS) 72.5% vs 95.6%, P = 0.039], lymphovascular invasion (58.3% vs 83.6%, P = 0.024), perineural invasion (75% vs 85.6%, P = 0.013), and depth of invasion ≥0.5 cm (73.8% vs 97.5%, P = 0.017) predicted 3-year DFS. Tongue lesions and poor differentiation were added as poor prognosticators based on previously published reports. Patients were grouped as low risk (<3 risk factors) and high risk (≥3 risk factors), with only high-risk group receiving adjuvant irradiation in validation cohort. Overall, 47/119 (39.5%) patients in the derivation cohort and 50/204 (24.5%) patients in validation cohort received adjuvant irradiation. In derivation cohort, 3-year DFS was 93% and 72.5% in the low and high-risk group, respectively. 3-year DFS was 90.7% and 85.8% in the low and high-risk group, respectively for validation cohort. The proposed scoring system reduced the use of adjuvant irradiation by 38%, with similar DFS.

Quality Assurance in Radiotherapy (RT)-Specific Trials: Indian Scenario.

AIMS: There is evidence that proper radiotherapy trial quality assurance (RTTQA) translates into improved outcomes for patients. However, the practice of RTTQA is heterogeneous and implemented in a diverse manner across trials. In this paper, we review the RTTQA report for randomised trials (RCT) conducted in India and present our experience with RTTQA for various clinical trials and highlight the key achievements and challenges. MATERIALS AND METHODS: Search was performed using the keywords and the variations thereof for "radiotherapy" and author affiliations from India, its states and major metropolitan cities. Pubmed search filters were used to restrict results to RCT published in the past 5 years (2019-2024). Reporting of RTTQA procedures from publications and protocols was documented along with the protocol-specified dosimetric goals. We also evaluated a few clinical trials performed in the Department of Radiation Oncology at Tata Medical Center. The different RTTQA procedures and results for four representative clinical trials have been described. RESULTS: A formal RTTQA process was reported by only one out of 24 randomised controlled trials and formal dosimetric goals were pre-specified by 9 of 13 trials where IMRT was used as treatment. RTTQA requirements were tailored for each clinical trial at Tata Medical Center. For the HYPORT trial, the RTTQA process focused on ensuring the matchline doses were homogenous. HYPORT B trial commissioned the use of a simultaneous integrated boost technique which emphasised conformal avoidance of dose spillage to contralateral breast and lung. HYPORT Adjuvant and PROPARA trials are multicentre clinical trials. While HYPORT Adjuvant focussed on ensuring that the dose delivery met the predefined constraints, segmentation of the target volume was important for the PROPARA trial. CONCLUSION: We demonstrate different RTTQA procedures required for representative clinical trials and highlight key challenges encountered.

Multi-Institutional Clinical Outcomes of Biopsy Gleason Grade Group 5 Prostate Cancers Treated With Contemporary High-Dose Radiation and Long-Term Androgen Deprivation Therapy.

AIMS: This multicentric retrospective study reports long-term clinical outcomes of non-metastatic grade group 5 prostate cancers treated with external beam radiotherapy (EBRT) alone with long-term androgen deprivation therapy (ADT). MATERIALS AND METHODS: Patients treated across 19 institutions were studied. The key endpoints that were evaluated were 5-year biochemical recurrence-free survival (bRFS), metastases-free survival (MFS), overall survival, together with EBRT-related acute and late toxicities. The impact of various prognostic factors on the studied endpoints was analysed using univariate and multivariate analyses. RESULTS: Among the 462 patients, 88% (405) had Gleason 9 disease and 31% (142) had primary Gleason pattern 5. A prostate-specific membrane antigen positron emission tomography-computed tomography scan was used for staging in 33% (153), 80% (371) were staged as T3/T4 and 30% (142) with pelvic nodal disease. The median ADT duration was 24 months; 66% received hypofractionated EBRT and 71.4% (330) received pelvic nodal irradiation. With a median follow-up of 56 months, the 5-year bRFS, MFS and overall survival were 73.1%, 77.4% and 90.5%, respectively. Primary Gleason pattern 5 was associated with worse bRFS, MFS and overall survival with hazard ratios of 0.51 (95% confidence interval 0.35 to 0.73, P < 0.001), 0.64 (95% confidence interval 0.43 to 0.96, P = 0.031) and 0.52 (95% confidence interval 0.28 to 0.97, P = 0.040), respectively, whereas pelvic nodal disease was associated with worse bRFS (hazard ratio 0.67, 95% confidence interval 0.46 to 0.98, P = 0.039) and MFS (hazard ratio 0.56, 95% confidence interval 0.37 to 0.85, P = 0.006). The acute and late radiation-related toxicities were low overall and pelvic nodal irradiation was associated with higher toxicities. CONCLUSION: Contemporary EBRT and long-term ADT led to excellent 5-year clinical outcomes and low rates of toxicity in this cohort of non-metastatic grade group 5 prostate cancers. Primary Gleason pattern 5 and pelvic node disease portends inferior clinical outcomes.

Moderately Hypofractionated Radiotherapy and Androgen Deprivation Therapy for High-risk Localised Prostate Cancer: Predictors of Long-term Biochemical Control and Toxicity.

AIMS: There is a paucity of long-term data on outcomes of high-risk prostatic adenocarcinoma after moderately hypofractionated radiotherapy with elective nodal treatment and long-term androgen deprivation therapy (ADT). We report long-term control and toxicity outcomes and analyse the predictors of failure and toxicity. MATERIALS AND METHODS: The records of 120 consecutive high-risk prostate cancer patients treated in a single institution between February 2012 and December 2016 were retrospectively analysed. A moderately hypofractionted radiotherapy (HypoRT) regimen of 60 Gy in 20 fractions over 4 weeks with simultaneous elective pelvic irradiation to 44 Gy in 20 fractions with intensity-modulated radiotherapy was used, together with long-term ADT with either orchiectomy or medical castration for a total duration of 2-3 years. We analysed biochemical control, metastasis-free survival and late toxicities and their predictive factors using survival analysis. RESULTS: Patients had locally advanced cancers (cT3 77.5%, median pretreatment prostate-specific antigen 30 ng/ml, Gleason score 8-10 in 45.8%). The median follow-up time was 70 months. The 3- and 5-year probability of freedom from biochemical progression was 93% and 80%, respectively. The 5-year probability of freedom from local relapse/intra-pelvic nodal relapse/distant metastases as the site of first failure was 96%/97%/86%, respectively. Gleason score 8-10 and medical ADT for 2-3 years (as opposed to orchidectomy) were independent risk factors for distant metastases. A total of 18 grade 2 and above late gastrointestinal toxicity events and a total of 23 grade 2 and above late genitourinary toxicity events were documented. Patients who underwent a transurethral resection of prostate prior to radiotherapy had worse urological toxicity. CONCLUSIONS: HypoRT with elective nodal treatment results in excellent pelvic control. Distant metastases are the primary mode of failure. Risk of metastases is associated with Gleason score and the duration of ADT. Late urinary toxicities are more common in those with prior transurethral resection of prostate.

Helical Radiotherapy in Early Laryngeal Cancers Could Lead to Excess Local Recurrence: Lessons From a Phase II Prospective Study.

AIMS: A prospective study was conducted to investigate the feasibility and efficacy of carotid-sparing intensity-modulated radiotherapy (CSIMRT) in early glottic cancers (EGC). MATERIALS AND METHODS: Eighteen patients underwent CSIMRT using helical tomotherapy to a dose of 55 Gy/20 fractions/4 weeks. Carotid intimal thickness (CIT) at prespecified carotid levels was measured using B-mode ultrasound at 6, 18 and 36 months. Serial changes in CIT were also measured in a control prospective cohort of 18 patients with head and neck cancers receiving bilateral neck nodal radiation over the same time period (54-60 Gy/30 fraction/6 weeks). The outcomes of 18 patients undergoing CSIMRT were compared against a retrospective consecutive cohort of 41 patients with EGC to confirm comparable local control. RESULTS: No significant CIT differences were identified between patients undergoing CSIMRT versus the control group. However, four patients in the CSIMRT group had a local recurrence between 8 and 39 months. In all patients the epicentre of the recurrence was noted at the anterior part of the larynx. The 5-year local recurrence-free survival was 75.1% (95% confidence interval 56.6-99.7%). By contrast, in the group of EGC patients treated without carotid sparing, local recurrence was noted only in a single patient (patient treated with helical tomotherapy) and the 5-year local recurrence-free survival was 97.1% (95% confidence interval 91.8-100%) (Log-rank P = 0.01). CONCLUSION: We failed to show the safety of CSIMRT using helical tomotherapy in this population of EGC patients. Use of CSIMRT also did not translate into a substantial reduction in CIT until 36 months. Use of CSIMRT using rotational arc techniques such as helical tomotherapy may be associated with a greater risk of local recurrence due to intrafractional motion interplay effects.

A Phase I/II Study of Stereotactic Hypofractionated Once-weekly Radiation Therapy (SHORT) for Prostate Cancer.

AIMS: Stereotactic radiation therapy has been investigated predominantly in patients with low-intermediate-risk disease. We conducted a clinical trial of stereotactic hypofractionated radiation therapy delivered in once-weekly fractions on patients with all-risk non-metastatic disease to test feasibility, acute toxicities and patient-reported outcomes. MATERIALS AND METHODS: In this phase I/II study, 30 patients with prostatic adenocarcinoma, any Gleason score, T1-4N0 and prostate-specific antigen ≤60 ng/ml were treated with volumetric intensity modulated arc radiation therapy to a dose of 35 Gy in five fractions delivered once weekly. Patients with high-risk disease also received elective nodal irradiation to a dose of 25 Gy in five fractions simultaneously. Androgen deprivation was offered to intermediate- and high-risk patients. The primary outcome was acute toxicity. Secondary outcome measures included biochemical control and late toxicity. Patient-reported outcomes were measured using the International Prostate Symptom Score and European Organization for Research and Treatment of Cancer (EORTC) Quality-of-Life Questionnaire (QLQ). RESULTS: All 30 patients completed treatment per-protocol. Most patients had T3 (60%) and Gleason 7 (50%) tumours. The median prostate-specific antigen was 17 ng/ml. High-risk disease was present in 20 patients (66.7%). There was a low incidence of acute toxicities (grade 2 + urinary 3.3%, grade 2 rectal 0%). Within the EORTC QLQ framework, only the urinary symptom score showed a clinically meaningful worsening from a mean of 20/100 at baseline to 34/100 at the end of treatment (P < 0.001), but reduced to 24/100 at 6 months (P = 0.08). With a median follow-up of 41.5 months, two patients each reported grade 2 late urinary and rectal toxicity. The 3- and 4-year biochemical control rates were 96.7 and 87.9%, respectively. CONCLUSION: In a cohort of mainly high-risk cancers, stereotactic once-weekly radiation therapy was easy to implement and well tolerated, with a low incidence of acute and late toxicity and excellent biochemical control.

Oral Cavity Cancer in the Indian Subcontinent - Challenges and Opportunities.

Oral cavity cancer (OCC) poses a global challenge that plagues both the Orient and the Occident, accounting for an estimated 350 000 new cases and 177 000 deaths in 2018. OCC is a major public health problem in the Indian subcontinent, where it ranks among the top three cancer types in both incidence and mortality. Major risk factors are the use of tobacco, betel quid and alcohol consumption. OCC is a heterogeneous group of multiple histologies that affects multiple subsites. The oral cavity includes the lips, buccal mucosa, teeth, gingiva, anterior two-thirds of the tongue, floor of the mouth and hard palate. OCC is defined as cancer of lips, mouth and tongue as defined by the International Classification of Diseases coding scheme. The epidemiology, aetio-pathogenesis and treatment philosophy are similar within this group. Although salivary gland malignancies, sarcomas, mucosal melanomas and lymphomas can also arise within the oral cavity, this review will focus on squamous cell cancer, which is the predominant histology in OCC. We review and contrast data from developing and developed countries. We also highlight the unique regional challenges that countries in the East face; citing India as an example, we elaborate on the opportunities and scope for improvement in the management of OCC.

Oropharyngeal Cancers in the East and the West - Implications of Aetiopathogenesis on Prognosis and Research.

There has been a surge in human papillomavirus (HPV)-positive oropharyngeal cancers (OPCs) in the West. Although the prognosis of HPV-positive OPC is good, de-escalation strategies have so far not been able to confirm comparable cancer control. We examine the strategies implemented across the globe to safely reduce toxicities in HPV-positive disease. HPV-negative OPC has a poorer prognosis and is more prevalent in Eastern countries. We outline the intensification strategies currently used in HPV-negative cancers, with an aim to better prognosis. With recent improvements in clinical trial frameworks in Eastern countries such as India, we discuss areas where joint collaborative research between Western and Eastern countries could further improve outcomes in OPC.

Prostate Radiotherapy in India: Evolution, Practice and Challenges in the 21st Century.

The practice of prostate radiotherapy is evolving rapidly while there is an increase in the incidence of prostate cancer in India. Here, the diverse socioeconomic milieu and varied healthcare delivery models interact to exert a significant influence on the adoption of new technologies and evidence emerging from the Western world. Using a targeted cross-country survey of radiation oncologists, this article captures the changing trends in prostate imaging, conformal techniques, dose escalation, hypofractionation, stereotactic ablation and prostate brachytherapy in the context of practice patterns in the West. New directions in research on prostate cancer are highlighted, reflecting the unique challenges of the disease profile and treatment resources in India.

Moderately Hypofractionated Radiotherapy in Node-positive Prostate Cancer.

AIMS: Node-positive prostate cancer is a unique subgroup, with varied practice on locoregional treatment. Definitive treatment with hypofractionated radiotherapy has not been widely reported. We have routinely used standard regimens of hypofractionated radiotherapy for node-positive disease and report our results of toxicity, biochemical control and survival. MATERIALS AND METHODS: Medical records of patients diagnosed with prostate cancer between February 2011 and April 2016 with radiologically involved pelvic nodes on magnetic resonance imaging/computed tomography without distant metastases were analysed. All patients were treated with long-term androgen deprivation therapy (ADT) and hypofractionated radiotherapy. Acute and late toxicities were assessed using Radiation Therapy Oncology Group acute and late morbidity scoring criteria. Biochemical control and survival were computed using Kaplan-Meier survival statistics. RESULTS: In total, 61 patients were identified with node-positive disease, with a median age of 68 years and a median initial prostate-specific antigen level of 40.1 ng/ml. Most, 50 (81.9%), had T3 disease; 47.6% had Gleason 8-10 disease. All were treated with hypofractionated intensity-modulated radiotherapy, predominantly 60 Gy/20 fractions/4 weeks, with a dose of 44 Gy/20 fractions to the pelvic nodes. Twenty-five patients (41%) who had residual radiologically enlarged nodes after 3-6 months of ADT received nodal boost to the involved nodes, to a dose of 54-60 Gy as simultaneous boost. Incidences of late grade 2 + gastrointestinal and genitourinary toxicities were 13.1 and 18%, respectively, with no grade 4 toxicities. With a median follow-up of 48 months, 15 (24.6%) patients developed biochemical failure, with only four locoregional failures. The 4-year biochemical control rate was 77.5% and overall survival was 91%. Patients who had residual enlarged nodes after initial ADT had worse biochemical control (53.9% versus 93.1% at 4 years, P < 0.001). CONCLUSION: Moderately hypofractionated radiotherapy using an established fractionation schedule with long-term ADT for node-positive prostate cancer patients is feasible and results in excellent biochemical control rates at 4 years, with acceptable late toxicity rates. The response to initial ADT predicts outcomes.

Continuous hyperfractionated accelerated radiotherapy using modern radiotherapy techniques for nonsmall cell lung cancer patients unsuitable for chemoradiation.

INTRODUCTION: The continuous hyperfractionated and accelerated radiotherapy (CHART) regimen of radiotherapy (RT) for nonsmall cell lung cancer is underused outside the UK. We present the first Indian experience of using CHART for patients, who were not suitable for chemotherapy or concurrent chemo-RT. METHODS: We retrospectively reviewed the data of patients treated using CHART at our institution between January 2014 and December 2015. RESULTS: Thirty-seven patients were treated using CHART. Planning methods and dosimetry parameters are described. Three-dimensional conformal RT was used for treatment planning and delivery in 23 patients and volumetric modulated arc RT was necessary for 14 patients. Patients in our series had a median age of 70 years (interquartile range 65.50-74.00) and 86.5% had Stage III disease. Median follow-up was short at 13.0 months. Actuarial rates of 1-year progression-free survival, 1-year overall survival (OS), and 2-year OS were 31.9%, 59.5%, and 28.5%, respectively. This treatment was well tolerated with manageable and some reversible acute esophageal toxicity (91.9% CONCLUSION: Our results indicate that CHART is feasible, safe, and well tolerated in Indian patients who are clinically found to be not suitable for either sequential or concurrent chemo- RT.

Actual gains in dosimetry and treatment delivery efficiency from volumetric modulated arc radiotherapy for inoperable, locally advanced lung cancer over five-field forward-planned intensity-modulated radiotherapy.

AIMS: Volumetric modulated arc radiotherapy (VMAT) is used for inoperable, locally advanced nonsmall cell lung cancer, where three-dimensional conformal radiotherapy (3D-CRT) cannot yield an acceptable plan. METHODS: The planning and treatment data were prospectively collected on the first 18 patients treated using VMAT plans. We analyzed the actual dosimetric gain and impact on treatment, compared with complex multisegment 3D-CRT (five-field forward-planned intensity-modulated radiotherapy [IMRT]) that were generated for treatment. Proportion of planning target volume (PTV) receiving 95% dose (PTV-V95%) conformity index (CI), conformity number (CN), dose homogeneity index (DHI), monitor units (MUs), and treatment time were also analyzed. RESULTS: The PTV coverage (PTV-V95%) was improved from a median of 91.41% for 5-F forward-IMRT to 98.25% for VMAT (P < 0.001). The CI improved with a mean of 1.12 for VMAT and 1.31 for 5-F forward-IMRT (P < 0.001). The mean DHI improved from 1.15 for forward-IMRT to 1.08 for VMAT (P < 0.001). The mean CN improved from 0.62 for forward-IMRT to 0.87 for VMAT (P < 0.001). No significant increase in the low-dose bath (V5, V10 and mean lung dose) to the lung was seen. Significantly higher number of MUs (P < 0.001) and shorter treatment delivery times (P = 0.03) were seen with VMAT. CONCLUSION: VMAT resulted in improvement in target volume coverage, demonstrated by PTV-V95%, CI, CN, and DHI, without any increase in the low-dose bath to the lung. For conventional fractionation, VMAT requires more MUs (P < 0.001) but has a shorter treatment delivery time (P = 0.03) per fraction.

Response to laparoscopic ventral rectopexy for rectal prolapse and rectal intussusception using a biological mesh.

We read with interest the article by Albayati et al published recently.1 There is a sparsity of long term data in use of biological mesh in laparoscopy rectopexy for the treatment of rectal prolapse. We appreciate the efforts made by Albayati et al in this study and note the homogeneous population in terms of gender, age and BMI. This article is protected by copyright. All rights reserved.

High-dose Neural Stem Cell Radiation May Not Improve Survival in Glioblastoma.

AIMS: To evaluate the effect of radiotherapy dose-volume parameters of neural stem cell (NSC) compartment on progression-free survival (PFS) and overall survival after post-resection chemoradiation in newly diagnosed glioblastoma. MATERIALS AND METHODS: Sixty-one patients with unifocal glioblastoma were included. Ipsilateral (NSC_Ipsi), contralateral (NSC_Contra) and combined NSC (NSC_Combined) were contoured on radiotherapy planning computerised tomography datasets. NSC dose-volume parameters were correlated with PFS and overall survival. Serial magnetic resonance imaging scans were assessed to understand the frequency of pre- and post-treatment involvement of the NSC by contrast enhancing lesions (CELs). RESULTS: Baseline involvement of NSC with CELs was seen in 67.2% and 95.9% had CELs and FLAIR abnormalities at progression. With a median follow-up of 14.1 months (interquartile range 9.4-20.6 months), median PFS and overall survival were 14.5 (95% confidence interval 11.6-17.5) and 16.2 (95% confidence interval 13.3-19.2) months, respectively. Poor Eastern Cooperative Oncology Group performance score, advanced recursive partitioning analysis class, unmethylated O6-methylguanine methyltransferase (MGMT) status, higher than median of mean NSC_Ipsi dose were associated with significantly inferior PFS and overall survival on univariate analysis. On multivariate analysis, unmethylated MGMT status, higher than median of mean doses to NSC_Ipsi and poor compliance to adjuvant temozolomide were independent predictors of inferior survival. CONCLUSIONS: In this cohort, 67.2% of newly diagnosed glioblastoma patients had NSC involved with CELs at presentation and 95.9% at progression. This might be an imaging surrogate of the current notion of gliomagenesis and progression from NSC rests. A high radiation dose to NSC_Ipsi was significantly associated with inferior survival. This could be a function of larger tumours and planning target volumes in those with pre-treatment NSC involvement. Methylated MGMT and good compliance to adjuvant temozolomide were independent predictors of better survival. Until further evidence brings hope for glioblastoma, elective, partial NSC irradiation remains experimental.

Outcomes Following a Moderately Hypofractionated Adjuvant Radiation (START B Type) Schedule for Breast Cancer in an Unscreened Non-Caucasian Population.

AIMS: Breast cancer is the most common cancer in women. Western data have confirmed hypofractionated radiation therapy to be safe and effective in the adjuvant radiation therapy of breast cancers. We report the disease-related outcomes in a non-Caucasian, unscreened population treated with hypofractionated radiation. MATERIALS AND METHODS: Unselected case notes of patients presenting to a tertiary cancer centre between June 2011 and December 2013 were reviewed from the electronic hospital case records. Patients with a diagnosis of non-metastatic invasive non-sarcomatous breast cancer were identified. Demographic information, oestrogen receptor (ER), progesterone receptor (PR), HER2 status, pathological tumour, nodal stage at diagnosis and outcomes of treatment, including systemic therapies, surgery and hypofractionated radiation, were documented. Local recurrence rates, disease-free survival (DFS) and overall survival were calculated. RESULTS: Overall 925 patents were identified, median age 53.0 years (interquartile range 45-61), 330 of whom had neoadjuvant chemotherapy. The median follow-up time was 22.6 months and 23.5 months for overall and neoadjuvant chemotherapy groups, respectively. ER, PR and HER2 status was available in 788 patients, 77.2% of whom were ER/PR positive, 14.7% had triple negative disease, while 9.5% were HER2 rich. Overall, 34.2% (113 patients) underwent breast conservation surgery; 744 (80.4%) patients were treated with systemic chemotherapy and 878 (94.9%) patients received adjuvant radiation therapy, of whom 407 (44.0%) received supraclavicular-fossa radiotherapy. Overall survival, DFS and locoregional recurrence-free survival (LRRFS) for the overall group were 93%, 86.9% and 97.1%, respectively. LRRFS in the breast conservation surgery versus mastectomy groups were 99% versus 95.5% (P=0.003), with more node-positive patients in the mastectomy group. Stage N0/1 had better LRRFS compared with N2/2 (99.1% versus 95.7%); 94.3% versus 82.3%; P=0.005, 0.000. Grade 3 (53.8%) tumours had worse overall survival compared with grade 1 or grade 2 disease (89.6% versus 100% and 96.4%; P<0.001) although the LRRFS was not significantly different between the groups (98.9% versus 97.8%; P=0.37). There was no difference in LRRFS based on molecular subtypes. CONCLUSION: Local recurrence rates following hypofractionated radiation in our population were comparable with those reported by the START trialists and were found to be safe in the medium term for patients irrespective of breast conservation surgery/mastectomy or radiotherapy to the supraclavicular field. Molecular group frequencies were comparable with Western populations but did not affect LRRFS.

Evaluating the Need for Daily Image Guidance in Head and Neck Cancers Treated with Helical Tomotherapy: A Retrospective Analysis of a Large Number of Daily Imaging-based Corrections.

AIMS: Clinical implementation of image-guided intensity-modulated radiotherapy is rapidly evolving. Helical tomotherapy treatment delivery involves daily imaging before intensity-modulated radiotherapy delivery. This can be a time consuming resource-intensive process, which may not be essential in head and neck radiotherapy, where effective immobilisation is possible. This study aimed to evaluate whether an offline protocol implementing the shifts derived from the first few fractions can be an acceptable alternative to daily imaging for helical tomotherapy. MATERIALS AND METHODS: We retrospectively analysed the set-up data of 2858 fractions of 100 head and neck cancer patients who were treated with daily online image guidance. Using summary data from all treatment fractions, we calculated the systematic error (∑) and random error (σ) in each of the three axes, i.e. mediolateral (x), craniocaudal (y), anteroposterior (z). We also calculated the translational vector of each fraction of individual patients. We then simulated two no-action-level offline protocols where set-up errors of the first three (protocol F3) or five fractions (protocol F5) were averaged and implemented for the remaining fractions. The residual errors in each axis for these fractions were determined together with the residual ∑ and σ. Planning target volume (PTV) margins using the van Herk formula were generated based on the uncorrected errors as well as for the F3 and F5 protocols. For each scenario, we tabulated the number of fractions where the residual errors were more than 5 mm (our default PTV margin). We also tried to evaluate whether errors tended to differ based on intent (radical or adjuvant), anatomical subsite or weight loss during treatment. RESULTS: Analysis from this large dataset revealed that in the tomotherapy platform, the highest set-up errors were in the anteroposterior (z) axis. The global mean was 5.4 mm posterior shift, which can be partly attributed to couch sag on this system. Uncorrected set-up errors resulted in systematic and random errors of ∑x,y,z of 1.8, 1.7 and 2 mm and σx,y,z of 1.7, 1.5 and 1.9 mm, with a required PTV margin in x, y, z axes of 5.7, 5.3 and 6.2 mm. Implementing average shifts from the first three or five fractions resulted in a substantial reduction in the residual systematic errors, whereas random errors remained constant. The PTV margins required for the residual errors after three and five fraction corrections were 3.8, 3.4 and 5.1 mm for F3 and 3.3, 2.9, 4.8 mm for F5. The proportions of fractions where there was >5 mm residual error were 1.6%, 1.1%, 2.9% in x, y and z axes in the F3 protocol and 1.5%, 0.8% and 2.6% with the F5 protocol. Although there was no difference in residual shifts > 5 mm, there was a statistically higher chance of residual errors > 3 mm larynx/hypopharynx subsites versus other sites. In patients who had more than 5% weight loss, there was no significant increase in residual errors with the F5 protocol and the required PTV margin was within our default PTV margins expansion. CONCLUSIONS: Correction of systematic errors by implementing average shifts from the first five fractions enables us to safely avoid daily imaging in this retrospective analysis. If this is validated in a prospective group it could lead to implementation of a resource sparing image-guided radiotherapy protocol both in terms of time and imaging dose. Patients with larynx/hypopharynx subsites may require more careful evaluation and daily online matching.

Therapeutic Neck Dissection in Oral Squamous Cell Carcinoma: Is Selective Neck Dissection the Way Ahead?

Background Selective neck dissection in multimodality treatment protocols is slowly being accepted for the management of N+ neck in many centers. This is because the functional disability is lower than modified radical neck dissection. Objective This study compares the regional recurrence rates between patients who underwent selective neck dissection and patients underwent comprehensive neck dissection for node positive oral squamous cell carcinoma. Method A retrospective study comparing patients with node positive oral squamous cell carcinoma who underwent either selective neck dissection or comprehensive neck dissection between August 2011 and January 2014 was done, with a mean follow up period of 12 months. Regional failures were assessed to whether they were isolated neck failures or associated with a local or distant failure. Result A total of 131 neck dissections were performed which included 93 selective neck dissections and 38 comprehensive neck dissections. A total of 17 patients developed regional recurrence, of which 11 patients had ipsilateral neck recurrence. Of the 11 patients with ipsilateral neck recurrence one patient also had contralateral neck nodes and in two patients there was associated distant metastasis. Conclusion Selective neck dissection for management of node positive neck disease is based on sound scientific principles and a randomised controlled trial comparing it with modified radical neck dissection would probably give the answer regarding the optimal procedure for these patients.