IMRT and IGRT in head and neck cancer: Have we delivered what we promised?

Image-guidance triggered adaptive radiation therapy in head and neck squamous cell carcinoma: single-institution experience and implications for clinical practice

PURPOSE

To report frequency and timing of adaptive radiotherapy (ART) and assess patient, disease, and treatment-related characteristics potentially triggering the need for such adaptive replanning in head and neck squamous cell carcinoma (HNSCC).

METHODS

Medical records of HNSCC patients treated with definitive intensity modulated radiation therapy (IMRT) with or without concurrent systemic chemotherapy were reviewed retrospectively to identify patients undergoing image-guidance triggered adaptive replanning. Clinico-demographic characteristics of patients undergoing ART were compared with patients treated without adaptation using the chi-square test.

RESULTS

Two hundred patients with squamous cell cancers of the oropharynx, larynx, or hypopharynx treated with definitive IMRT between 2014 to 2019 comprised the study cohort. Twenty-seven (13.5%) patients underwent adaptive replanning during treatment at a median of 17 fractions (inter-quartile range 14-24 fractions). There were no significant differences in the baseline patient (age, gender), disease (site of primary, staging/grouping), and treatment-related characteristics (dose-fractionation, chemotherapy usage) in patients undergoing ART compared to those treated without adaptation. Weight loss during IMRT emerged as a significant factor predicting the need for ART; patients having ≥10% weight loss from baseline were more likely to undergo treatment adaptation compared to patients with <10% weight loss (p = 0.0002). There was variable impact of ART on dose-volume statistics of organs-at-risk such parotid glands and spinal cord.

CONCLUSION

Image-guidance triggered ART for HNSCC is not associated with significant improvement in OAR dosimetry. However, weight loss during definitive IMRT can be a potentially useful trigger for identifying patients who are most likely to benefit from such adaptive replanning.

Comparison of Volumetric Quantitative PET Parameters Before and After a CT-Based Elastic Deformation on Dual-Time 18FDG-PET/CT Images: A Feasibility Study in a Perspective of Radiotherapy Planning in Head and Neck Cancer

Background

The use of 18FDG-PET/CT for delineating a gross tumor volume (GTV, also called MTV metabolic tumor volume) in radiotherapy (RT) planning of head neck squamous cell carcinomas (HNSCC) is not included in current recommendations, although its interest for the radiotherapist is of evidence. Because pre-RT PET scans are rarely done simultaneously with dosimetry CT, the validation of a robust image registration tool and of a reproducible MTV delineation method is still required.

Objective

Our objective was to study a CT-based elastic registration method on dual-time pre-RT 18FDG-PET/CT images to assess the feasibility of PET-based RT planning in patients with HNSCC.

Methods

Dual-time 18FDG-PET/CT [whole-body examination (wbPET) + 1 dedicated step (headPET)] were selected to simulate a 2-times scenario of pre-RT PET images deformation on dosimetry CT. ER-headPET and RR-headPET images were, respectively, reconstructed after CT-to-CT rigid (RR) and elastic (ER) registrations of the headPET on the wbPET. The MTVs delineation was performed using two methods (40%SUVmax, PET-Edge). The percentage variations of several PET parameters (SUVmax, SUVmean, SUVpeak, MTV, TLG) were calculated between wbPET, ER-headPET, and RR-headPET. Correlation between MTV values was calculated (Deming linear regression). MTVs intersections were assessed by two indices (OF, DICE) and compared together (Wilcoxon test). Additional per-volume analysis was evaluated (Mann-Whitney test). Inter- and intra-observer reproducibilities were evaluated (ICC = intra-class coefficient).

Results

36 patients (30M/6F; median age = 65 y) were retrospectively included. The changes in SUVmax, SUVmean and SUVpeak values between ER-headPET and RR-headPET images were <5%. The variations in MTV values between ER-headPET and wbPET images were −6 and −3% with 40%SUVmax and PET Edge, respectively. Their correlations were excellent whatever the delineation method (R² > 0.99). The ER-headPET MTVs had significant higher mean OF and DICE with the wbPET MTVs, for both delineation methods (p ≤ 0.002); and also when lesions had a volume > 5cc (excellent OF = 0.80 with 40%SUVmax). The inter- and intra-observer reproducibilities for MTV delineation were excellent (ICC ≥ 0.8, close to 1 with PET-Edge).

Conclusion

Our study demonstrated no significant changes in MTV after an elastic deformation of pre-RT 18FDG-PET/CT images acquired in dual-time mode. This opens possibilities for HNSCC radiotherapy planning improvement by transferring GTV-PET on dosimetry CT.

Evaluation of daily dose accumulation with deformable image registration method using helical tomotherapy images for nasopharyngeal carcinoma

Aim:

Nasopharyngeal carcinoma (NPC) patients may have anatomical variations during their radiotherapy treatment course. In this study, we determine the daily accumulated dose by the deformable image registration (DIR) process for comparing with the planned dose and explore the number of fractions which the daily accumulated dose significantly changed from the planned dose.

Methods:

The validation of the DIR process in MIM software has been tested. One hundred and sixty-five daily megavoltage computed tomography (MVCT) images of NPC patients who were treated by helical tomotherapy were exported to MIM software to determine the daily accumulated dose and then compared with the planned dose.

Results:

The MIM software illustrated the acceptable validation for clinical application. The accumulated dose (D50%) of the planning target volume (PTV70) showed a decrease from the planned dose with an average of 0.5 ± 0.27% at the end of the treatment and was significantly different from the planned dose after the second fraction of the treatment (p-value = 0.008). In contrast, the accumulated dose of organ at risk (OAR) tended to increase from the planned dose and was significantly different after the fifth fraction (left parotid), the twelfth fraction (right parotid) and the second fraction (spinal cord).

Findings:

The inter-fractional anatomic changes cause the actual dose to be different from the planned dose. The dose differences and the number of fractions were varied in each target and OAR. The dose accumulation explored the necessary information for the radiation oncologist to consider adaptive treatment strategies to increase the efficiency of treatment.

Dental radiation dosimetric maps from intensity-modulated radiation therapy planning for head and neck cancers

BACKGROUND

The purpose of this study was to create dental radiation maps to calculate the mean dose to individual teeth, maxilla and mandible using intensity-modulated radiation therapy (IMRT).

METHODS

Eighteen common clinical settings were chosen. Radiation plans were extracted, and each tooth was contoured at its junction with the gingiva and labeled based on the Universal/American numbering system.

RESULTS

All patients were treated with prescribed doses of 50-70 Gy in 1.66-2 Gy/fraction. Patients receiving mean doses >50 Gy to the teeth, mandible, and maxilla included those with advanced tumors of the oral cavity and gross lymphadenopathy of level 1b.

CONCLUSION

We believe this to be the first study generating dosimetric maps of estimated doses to each tooth and each third of the mandible and the maxilla for common examples of head and neck cancer faced by radiation oncologists. Adoption of these dental maps may help improve clinical workflow efficiency.

Correlation Between FDG Hotspots on Pre-radiotherapy PET/CT and Areas of HNSCC Local Relapse: Impact of Treatment Position and Images Registration Method

Aim: Several series have already demonstrated that intratumoral subvolumes with high tracer avidity (hotspots) in 18F-flurodesoxyglucose positron-emission tomography (FDG-PET/CT) are preferential sites of local recurrence (LR) in various solid cancers after radiotherapy (RT), becoming potential targets for dose escalation. However, studies conducted on head and neck squamous cell carcinoma (HNSCC) found only a moderate overlap between pre- and post-treatment subvolumes. A limitation of these studies was that scans were not performed in RT treatment position (TP) and were coregistred using a rigid registration (RR) method. We sought to study (i) the influence of FDG-PET/CT acquisition in TP and (ii) the impact of using an elastic registration (ER) method to improve the localization of hotpots in HNSCC.

Methods: Consecutive patients with HNSCC treated by RT between March 2015 and September 2017 who underwent FDG-PET/CT in TP at initial staging (PET_A) and during follow-up (PET_R) were prospectively included. We utilized a control group scanned in non treatment position (NTP) from our previous retrospective study. Scans were registered with both RR and ER methods. Various sub-volumes (A_X; x = 30, 40, 50, 60, 70, 80, and 90%SUVmax) within the initial tumor and in the subsequent LR (R_X; x = 40 and 70%SUVmax) were overlaid on the initial PET/CT for comparison [Dice, Jaccard, overlap fraction = OF, common volume/baseline volume = A_XnR_X/A_X, common volume/recurrent volume = A_XnR_X/R_X].

Results: Of 199 patients included, 43 (21.6%) had LR (TP = 15; NTP = 28). The overlap between A₃₀, A₄₀, and A₅₀ sub-volumes on PET_A and the whole metabolic volume of recurrence R₄₀ and R₇₀ on PET_R showed moderate to good agreements (0.41–0.64) with OF and A_XnR_X/R_X index, regardless of registration method or patient position. Comparison of registration method demonstrated OF and A_XnR_X/R_X indices (x = 30% to 50%SUVmax) were significantly higher with ER vs. RR in NTP (p < 0.03), but not in TP. For patient position, the OF and A_XnR_X/R_X indices were higher in TP than in NTP when RR was used with a trend toward significance, particularly for x=40%SUVmax (0.50±0.22 vs. 0.31 ± 0.13, p = 0.094).

Conclusion: Our study suggested that PET/CT acquired in TP improves results in the localization of FDG hotspots in HNSCC. If TP is not possible, using an ER method is significantly more accurate than RR for overlap estimation.

Dosimetric comparison between three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT) in the treatment of different stages of nasopharyngeal carcinoma

Background

This work aims to compare the dosimetric performance of three-dimensional conformal radiotherapy (3D-CRT), a relatively available technique in developing countries, to intensity-modulated radiotherapy (IMRT) in the treatment of different stages of nasopharyngeal carcinoma (NPC).

Materials and Methods

According to the diagnostic stages, 40 NPC patients were divided into two equal groups. Three planning techniques such as 3D-CRT, seven-field IMRT (7F-IMRT) and nine-field IMRT (9F-IMRT) were compared. Dose prescriptions of 70 and 66 Gy were delivered in 35 fractions to gross planning target volume (PTV1) and bilateral retropharyngeal carcinoma (PTV2), respectively.

Results

Stage I dose data for almost all of the three investigated planning techniques obey the international recommendations. The dose delivered to PTV1 and PTV2 for 3D-CRT and 7F-IMRT are statistically similar, whereas 9F-IMRT is significantly better than 3D-CRT. For organs at risk (OARs), the delivered dose is significantly better for 9F-IMRT compared with the other two techniques, whereas 7F-IMRT is significantly better than 3D-CRT.

Conclusions

3D-CRT is an acceptable alternative treatment technique for stage I NPC patients in developing countries suffering from the lack of advanced radiotherapy treatment techniques. 3D-CRT and 7F-IMRT have comparable performance in PTVs, while 9F-IMRT is superior in PTVs and OARs.

Systematic review and meta-analyses of intensity-modulated radiation therapy versus conventional two-dimensional and/or or three-dimensional radiotherapy in curative-intent management of head and neck squamous cell carcinoma

Introduction

Technological advancements in treatment planning and delivery have propelled the use of intensity-modulated radiation therapy (IMRT) in head and neck squamous cell carcinoma (HNSCC). This review compares IMRT with conventional two-dimensional (2D) and/or three-dimensional (3D) radiotherapy (RT) in curative-intent management of HNSCC.

Methods

Only randomized controlled trials (RCTs) offering curative-intent RT in patients with non-metastatic HNSCC were included. Outcome data was extracted independently by two reviewers, pooled using the Cochrane methodology, and expressed as risk ratio (RR) or hazard ratio (HR) as appropriate with 95% confidence intervals (CIs). Xerostomia was the primary outcome of interest whereas loco-regional control, overall survival and quality-of-life (QOL) were secondary endpoints.

Results

Seven RCTs involving 1155 patients directly comparing IMRT with 2D/3D-RT in HNSCC were included. The primary objective in five of seven index RCTs was reduction in xerostomia, with only one trial each using loco-regional control and overall survival as primary endpoints for sample size calculation. The use of IMRT was associated with a 36% relative risk reduction in ≥grade 2 acute xerostomia (RR = 0.64, 95%CI = 0.49–0.84; p = 0.001) compared to 2D/3D-RT. More importantly, IMRT significantly reduced the risk of ≥grade 2 late xerostomia (RR = 0.44, 95%CI = 0.34–0.57; p = 0.00001) compared to non-IMRT techniques at all time-points. Within the limitations of inadequate sample size and low statistical power, IMRT also resulted in 24% relative reduction in the risk of loco-regional relapse (HR = 0.76, 0.57–1.01; p = 0.06) and 30% relative reduction in risk of death (HR = 0.70, 95%CI = 0.57–0.88; p = 0.002) compared to 2D/3D-RT. However, this benefit of IMRT for loco-regional control and overall survival was limited to nasopharyngeal cancer patients alone, with no significant difference in efficacy between the two techniques in patients with cancers of the laryngo-pharynx in this analysis, highlighting the inconsistency in results of subgroup analyses stratified by primary site. Inadequate reporting of data precluded statistically pooling of results for QOL outcomes.

Conclusions

There is consistent moderate-quality evidence that IMRT significantly reduces the risk of moderate to severe acute and late xerostomia compared to 2D/3D-RT in curative-intent radiotherapeutic management of HNSCC. However, the quality of evidence regarding the superiority of IMRT over conventional techniques for disease-related endpoints is rather low due to relative lack of power and inconsistency of results precluding robust conclusions.

Reduced toxicity with three-dimensional conformal radiotherapy or intensity-modulated radiotherapy compared with conventional two-dimensional radiotherapy for esophageal squamous cell carcinoma: a secondary analysis of data from four prospective clinical trials

We conducted a retrospective analysis to assess the toxicity and long-term survival of esophageal squamous cell carcinoma patients treated with three-dimensional conformal radiotherapy (3DCRT) or intensity-modulated radiotherapy (IMRT) versus conventional two-dimensional radiotherapy (2DRT). All data in the present study were based on four prospective clinical trials conducted at our institution from 1996 to 2004 and included 308 esophageal squamous cell carcinoma patients treated with 2DRT or 3DCRT/IMRT. Based on the inclusion and exclusion criteria, 254 patients were included in the analysis. Of these patients, 158 were treated with 2DRT, whereas 96 were treated with 3DCRT/IMRT. The rates of ≥Grade3 acute toxicity of the esophagus and lung were 11.5% versus 28.5% (P = 0.002) and 5.2% versus 10.8% (P = 0.127) in the 3DCRT/IMRT and 2DRT groups, respectively. The incidences of ≥Grade 3 late toxicity of the esophagus and lungs were 3.1% versus 10.7% (P = 0.028) and 3.1% versus 5.7% (P = 0.127) in the 3DCRT/IMRT and 2DRT groups, respectively. The 1-year, 3-year and 5-year estimated overall survival rates were 81%, 38% and 34% in the 3DCRT/IMRT group and 79%, 44% and 31% in the 2DRT group, respectively (P = 0.628). The 1-year, 3-year and 5-year local control rates were 88%, 71% and 66% in the 3DCRT/IMRT group and 84%, 66% and 60% in the 2DRT group, respectively (P = 0.412). Fewer incidences of acute and late toxicities were observed in esophageal squamous cell carcinoma patients treated with 3DCRT/IMRT compared with those treated with 2DRT. No significant survival benefit was observed with the use of 3DCRT/IMRT.

The Indian scenario of head and neck oncology - Challenging the dogmas

Head and neck cancers (HNCs) are the most common malignancies worldwide. Asian populations bear major burden of this disease, with certain unique characteristics. Although significant research in HNCs is ongoing globally, many clinical issues still remain unanswered. We performed a literature search to find noteworthy Indian studies that changed practice of HNC as well as to look for areas for further research in this field. Many randomized controlled trials as well as large patient series are reported in the field of radiotherapy, chemotherapy, and surgical management of HNC. Still, many areas such as palliative therapy, targeted agents, and newer chemotherapeutic agents remain unexplored. Planned collaborative research is need of the hour to provide more evidenced based.

Assessment of voice, speech, and related quality of life in advanced head and neck cancer patients 10-years+ after chemoradiotherapy

OBJECTIVES

Assessment of long-term objective and subjective voice, speech, articulation, and quality of life in patients with head and neck cancer (HNC) treated with concurrent chemoradiotherapy (CRT) for advanced, stage IV disease.

MATERIALS AND METHODS

Twenty-two disease-free survivors, treated with cisplatin-based CRT for inoperable HNC (1999-2004), were evaluated at 10-years post-treatment. A standard Dutch text was recorded. Perceptual analysis of voice, speech, and articulation was conducted by two expert listeners (SLPs). Also an experimental expert system based on automatic speech recognition was used. Patients' perception of voice and speech and related quality of life was assessed with the Voice Handicap Index (VHI) and Speech Handicap Index (SHI) questionnaires.

RESULTS

At a median follow-up of 11-years, perceptual evaluation showed abnormal scores in up to 64% of cases, depending on the outcome parameter analyzed. Automatic assessment of voice and speech parameters correlated moderate to strong with perceptual outcome scores. Patient-reported problems with voice (VHI>15) and speech (SHI>6) in daily life were present in 68% and 77% of patients, respectively. Patients treated with IMRT showed significantly less impairment compared to those treated with conventional radiotherapy.

CONCLUSION

More than 10-years after organ-preservation treatment, voice and speech problems are common in this patient cohort, as assessed with perceptual evaluation, automatic speech recognition, and with validated structured questionnaires. There were fewer complaints in patients treated with IMRT than with conventional radiotherapy.

Prospective randomized controlled trial to compare 3-dimensional conformal radiotherapy to intensity-modulated radiotherapy in head and neck squamous cell carcinoma: Long-term results

BACKGROUND

Grade ≥2 acute xerostomia between 3D conformal radiotherapy (RT) and intensity-modulated radiotherapy (IMRT) was evaluated in patients with head and neck squamous cell carcinomas (HNSCCs) treated radically.

METHODS

Between 2005 and 2007, 59 patients with HNSCC (T1-3, N0-2b) were randomized to IMRT or 3D-RT. On RT, weekly xerostomia, dysphagia, dermatitis, and mucositis were graded by Radiation Therapy Oncology Group (RTOG) acute toxicity criteria. Patients underwent examination under anesthesia, positron emission tomography (PET)-CT, and toxicity assessments per protocol (NCT00652613) thereafter.

RESULTS

Incidence of grade ≥2 xerostomia at 8 weeks posttreatment was significantly lower with IMRT compared with 3D conformal RT (24% vs 53%; p = .024). At subsequent follow-up, significantly fewer patients receiving IMRT had grade ≥2 xerostomia. Long-term weight loss was higher in patients in the 3D conformal RT arm compared to IMRT (50% vs 21%; p = .038). Disease-related outcomes between arms (median follow-up, 70 months) were similar.

CONCLUSION

IMRT significantly reduces incidence of acute and late grade ≥2 xerostomia in patients with HNSCC. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1481-E1487, 2016.

Quality-of-life (QOL) outcomes in patients with head and neck squamous cell carcinoma (HNSCC) treated with intensity-modulated radiation therapy (IMRT) compared to three-dimensional conformal radiotherapy (3D-CRT): evidence from a prospective randomized study

PURPOSE

To prospectively evaluate and compare health-related quality-of-life (QOL) outcomes in patients with head-neck squamous cell carcinoma randomized to either intensity-modulated radiation therapy (IMRT) or three-dimensional conformal radiotherapy (3D-CRT) and assess serial longitudinal change in QOL over time.

METHODS

QOL outcomes were assessed using the European Organization for Research and Treatment of Cancer (EORTC) QOL questionnaire (QLQ-C30) and Head-Neck module (HN-35) at baseline (pre-treatment) and subsequently periodically on follow-up. Mean scores of individual domains/scales of 3D-CRT and IMRT were compared using 't' test at each time point; while longitudinal change in mean scores of both groups over time was evaluated by repeated measurement analysis of variance.

RESULTS

Fifty eight of the 60 randomized patients who filled the QOL questionnaire at least at one time point were included in the analysis. Several general (emotional functioning, role functioning, social contact) as well as head and neck cancer-specific (dry mouth, opening mouth, sticky saliva, pain, senses) QOL domains were better preserved with IMRT compared to 3D-CRT at different time points. Importantly, none of the QOL domains were worse with IMRT at any time point. There was substantial deterioration in QOL scores immediate post-treatment (3-months) in both arms. However, QOL scores gradually but definitely improved over time for most domains. Global QOL, emotional/role functioning, nausea/vomiting, pain, swallowing, speech, social contact/eating, insomnia showed rapid recovery (<6months) while physical/cognitive functioning, dry mouth, sticky saliva, fatigue, senses showed delayed recovery (>6months). There were no significant differences in loco-regional or survival between the two arms.

CONCLUSIONS

There is substantial deterioration in QOL after curative-intent head-neck irradiation that gradually improves over time. IMRT results in clinically meaningful and statistically better QOL scores for some domains compared to 3D-CRT at several time points with comparable disease outcomes that could support its widespread adoption in routine clinical practice.

Three-dimensional conformal radiotherapy (3D-CRT) versus intensity modulated radiation therapy (IMRT) in squamous cell carcinoma of the head and neck: a randomized controlled trial

PURPOSE

To compare three-dimensional conformal radiotherapy (3D-CRT) with intensity modulated radiation therapy (IMRT) in curative-intent irradiation of head-neck squamous cell carcinoma (HNSCC).

METHODS

Previously untreated patients with biopsy-proven squamous carcinoma of oropharynx, larynx, or hypopharynx (T1-3, N0-2b) were randomly assigned using computer-generated permuted-block design to either 3D-CRT or IMRT, with incidence of physician-rated Radiation Therapy Oncology Group (RTOG) grade 2 or worse acute salivary gland toxicity as primary end-point.

RESULTS

Between 2005 and 2008, 60 patients randomly allocated to either 3D-CRT (n=28 patients) or IMRT (n=32) were included and analyzed on an intention-to-treat basis. The proportion [95% confidence intervals (CI)] of patients with RTOG grade 2 or worse acute salivary gland toxicity was significantly lesser in the IMRT arm [19 of 32 patients (59%, 95%CI: 42-75%)] as compared to 3D-CRT [25 of 28 patients (89%, 95%CI: 72-97%; p=0.009)]. Late xerostomia and subcutaneous fibrosis were also significantly lesser with IMRT. There was significant recovery of salivary function over time in patients treated with IMRT (p-value for trend=0.0036). At 3-years, there were no significant differences in loco-regional control or survival between the two arms.

CONCLUSION

IMRT significantly reduces the incidence and severity of xerostomia compared to 3D-CRT in curative-intent irradiation of HNSCC.