Outcomes between intensity-modulated radiation therapy versus 3D-conformal in early stage glottic cancer

Patterns of Care for T1 Glottic Squamous Cell Carcinomas from 2004-2020

OBJECTIVE(S)

Describe recent national trends in overall treatment modalities for T1 glottic squamous cell carcinomas (SCC), and identify factors associated with treatment regimens.

METHODS

National Cancer Database from 2004-2020 was queried for all patients with glottic cT1N0M0 SCC. Treatment patterns over time were analyzed using the Cochran-Armitage test for trend. Multivariable logistic regressions were used to determine the factors associated with treatment regimens.

RESULTS

Of the 22,414 patients identified, most patients received RT only (57%), 21% received surgery only, and 22% received dual-modality treatment ("over-treatment"). Over the time period, there was a decreasing trend in rates of over-treatment for T1 glottic SCC (p < 0.001) and an increasing trend in surgery only (p < 0.001). Treatment in 2016-2018 (OR: 1.168 [1.004 to 1.359]), 2013-2015 (OR: 1.419 [1.221 to 1.648]), 2010-2012 (OR: 1.611 [1.388 to 1.871]), 2007-2009 (OR: 1.682 [1.450 to 1.951]), or 2004-2006 (OR: 1.795 [1.548 to 2.081]) versus 2019-2020 was associated with greater likelihood of over-treatment. T1b tumors were less likely to be over-treated (OR: 0.795 [0.707 to 0.894]) versus T1a tumors, and less likely to receive surgery first (OR: 0.536 [0.485 to 0.592]) versus T1a tumors.

CONCLUSION

Over-treatment for T1 glottic SCC has been declining, with increasing rates of surgery only. Year of treatment was significantly associated with the receipt of dual-modality treatment. Finally, patients with T1b disease were more likely to receive RT as the first and only treatment.

LEVEL OF EVIDENCE

3 Laryngoscope, 134:3633-3644, 2024.

Late coronary artery injury following chemoradiotherapy for thymic carcinoma: a case report

INTRODUCTION

Surgery remains the primary treatment modality for thymic carcinoma, with adjuvant radiotherapy being recommended to effectively mitigate local recurrence and metastasis rates subsequent to incomplete or complete resection. Chemoradiotherapy has the potential to induce coronary artery occlusion, thereby potentially impacting patients' long-term survival rates. The existing literature currently lacks comprehensive research on the lesion characteristics of coronary artery injury resulting from chemoradiotherapy.

CASE PRESENTATION

The male patient, aged 55, was admitted to the hospital due to recurrent chest tightness and pain persisting for one week. Notably, the patient had previously undergone curative resection surgery for thymic carcinoma seven years ago. After the surgical procedure, the patient underwent a course of adjuvant chemotherapy comprising docetaxel and platinum. 11 months later, imaging examination diagnosed tumor recurrence, and concurrent chemoradiotherapy was administered at a total dose of 62 Gy/31F for planning gross target volume (PGTV) and 54 Gy/31F for planning target volume (PTV) with 2 cycles of paclitaxel and cisplatin. Re-admission of the patient occurred after a 7-year interval subsequent to the completion of concurrent chemoradiotherapy, leading to a subsequent diagnosis of acute non-ST segment elevation myocardial infarction. Following administration of antiplatelet, anticoagulant, and anti-myocardial ischemia therapy, coronary angiography revealed the presence of a bifurcation lesion at the distal end of the left main trunk. Intravascular ultrasound (IVUS) examination demonstrated significant negative remodeling of both the main trunk and its branches at the bifurcation site, characterized by minimal atherosclerotic plaque components.

CONCLUSIONS

Chemoradiotherapy may induce damage to endothelial cells, resulting in an inflammatory response. Negative remodeling of blood vessels is likely to occur, primarily characterized by vasoconstriction but with less atherosclerotic plaque burden. Routine stent implantation in negatively remodeled areas may lead to vascular rupture, necessitating intravascular imaging examination.

Dosimetric impact of VMAT delivery angles for early glottic cancer treatment

This study investigates the dosimetric effects of different gantry rotation angles used in volumetric modulated arc therapy (VMAT) for early glottic carcinoma. VMAT treatment plans using full-arc, half-arc, and partial-arc gantry rotation angles were generated from 22 computed tomography datasets of early-stage (T1-2N0) glottic laryngeal cancer. Dosimetric parameters associated with the planning target volume (PTV) and organs at risk (OARs), specifically the carotid arteries and thyroid, were compared. To assess the robustness of the VMAT plans, dose variations were analyzed by introducing positional shifts of 1, 3, and 5 mm from the isocenter of each plan along the superior-inferior, left-right, and anterior-posterior axes. Furthermore, we examined the size of the PTV, the air cavity volume within the PTV, and the variability of the beam path length through the gantry angles to investigate their correlations with PTV dose variations in the presence of positioning errors. Compared to full-arc and half-arc plans, the dosimetric parameters of partial-arc plans were found to be higher in PTV (D2%, D5%, D50%, and Dmean) and lower in OARs, while their dose variations of OAR parameters were greater for positioning errors. In addition, a correlation was observed between PTV size and PTV dose variations. Air cavity volume and depth variability were also correlated with some PTV parameters, depending on the arc plan. The results presented in this study suggest that the partial-arc gantry angles can allow higher PTV doses while minimizing OAR doses in VMAT treatment planning for early glottic cancer. However, the small delivery angles may lead to greater dose variations in the OARs when positioning errors occur.

Latin American Consensus on the Treatment of Head and Neck Cancer

Head and neck squamous cell carcinoma (HNSCC) is well known as a serious health problem worldwide, especially in low-income countries or those with limited resources, such as most countries in Latin America. International guidelines cannot always be applied to a population from a large region with specific conditions. This study established a Latin American guideline for care of patients with head and neck cancer and presented evidence of HNSCC management considering availability and oncologic benefit. A panel composed of 41 head and neck cancer experts systematically worked according to a modified Delphi process on (1) document compilation of evidence-based answers to different questions contextualized by resource availability and oncologic benefit regarding Latin America (region of limited resources and/or without access to all necessary health care system infrastructure), (2) revision of the answers and the classification of levels of evidence and degrees of recommendations of all recommendations, (3) validation of the consensus through two rounds of online surveys, and (4) manuscript composition. The consensus consists of 12 sections: Head and neck cancer staging, Histopathologic evaluation of head and neck cancer, Head and neck surgery-oral cavity, Clinical oncology-oral cavity, Head and neck surgery-oropharynx, Clinical oncology-oropharynx, Head and neck surgery-larynx, Head and neck surgery-larynx/hypopharynx, Clinical oncology-larynx/hypopharynx, Clinical oncology-recurrent and metastatic head and neck cancer, Head and neck surgery-reconstruction and rehabilitation, and Radiation therapy. The present consensus established 48 recommendations on HNSCC patient care considering the availability of resources and focusing on oncologic benefit. These recommendations could also be used to formulate strategies in other regions like Latin America countries.

Accelerated three-dimensional conformal radiotherapy for early-stage glottic cancer in reducing dose to the internal carotid artery and pharyngeal constrictor muscles

BACKGROUND

We evaluated clinical and dosimetric outcomes of radiotherapy using two anterior oblique portals (AOP), to reduce the dose to the bilateral internal carotid arteries (CAs) and pharyngeal constrictor muscle (PCM) during early-stage glottic cancer (ESGC) treatment.

METHODS

We identified patients with ESGC who underwent definitive radiotherapy between June 2014 and May 2020.

RESULTS

Among the 66 patients, 32 (48%) underwent radiotherapy using AOP, and the remaining underwent typical radiotherapy using parallel opposed lateral portals (POLP). The median follow-up duration was 53 months. No significant differences were observed in the 5-year local failure (0%/9.4%), progression-free survival (90.6%/90.8%), and overall survival (90.6%/91.0%) rates between the two groups. The grade ≥2 acute mucositis incidence rate was significantly lower in the AOP group (44%/85%). Radiotherapy using AOP maintained an adequate dose coverage to the target while markedly reducing the CAs and PCM doses.

CONCLUSION

Radiotherapy with AOP resulted in favorable clinical and dosimetric outcomes.

Intensity-Modulated Radiation Therapy for Early-Stage Squamous Cell Carcinoma of the Glottic Larynx: A Systematic Review and Meta-Analysis

PURPOSE

Early-stage squamous cell carcinoma of the glottic larynx is commonly treated with 2-dimensional or 3-dimensional conventional radiation therapy (CRT). Despite its use in other head and neck cancers, intensity-modulated radiation therapy (IMRT) remains controversial in this patient population.

METHODS AND MATERIALS

A systematic review was performed by querying 3 databases (Pubmed, Embase, Web of Science) for articles published between December 1, 2000 and September 2, 2022. Included studies reported outcomes in at least 10 patients treated with IMRT for early-stage glottic cancer. Data were extracted and reported following PRISMA standards. Pooled outcomes were estimated using random-effects models. Primary outcome was the rate of local failure (LF) following IMRT. Secondary outcomes included rates of regional failure (RF) following IMRT and rates of LF and RF following CRT.

RESULTS

A total of 15 studies (14 retrospective, 1 prospective) consisting of 2083 patients were identified. IMRT was used in 873 patients (64% T1, 28% T2). Multiple treatment (partial larynx, single vocal cord carotid sparing) and image-guided radiation therapy techniques were used. The pooled crude rate of LF was 7.6% (95% confidence inverval [CI], 3.6%-11.5%) and actuarial LF rates at 3 and 5 years were 6.3% (95% CI, 2.2%-10.3%) and 9.0% (95% CI, 4.4%-13.5%), respectively. The pooled crude rate of RF after IMRT was 1.5% (95% CI, 0.5%-2.5%). On metaregression analysis, increased rate of LF was significantly associated with T2 disease (P < .001) and grade 2 to 3 histology (P < .001). Treatment with CRT was reported in 738 patients (76% T1, 22% T2). Among the studies reporting outcomes of both modalities, there was no significant difference in LF (log odds ratio; P = .12) or RF (log odds ratio; P = .58) between IMRT or CRT.

CONCLUSIONS

In patients with early-stage glottic cancer, retrospective data suggests local and regional control are similar for patients treated with IMRT and CRT. Additional prospective studies with uniform methods of volume delineation and image guidance are needed to confirm the efficacy of IMRT.

Radiation for Early Glottic Cancer

Multidisciplinary evaluation of early-stage glottic cancer facilitates optimal treatment with either surgery or radiation therapy. Standard of care radiation treatment of early-stage glottic cancer continues to be three-dimensional opposed lateral fields to include the whole larynx. Modern radiation treatment techniques are allowing studies to examine the efficacy and toxicity of altered doses and treatment volumes. Advanced techniques, such as stereotactic body radiation therapy or single-vocal cord irradiation, are not yet considered standard of care for early-stage glottic cancer and should be performed at institutions with clinical trials to ensure adequate expertise and quality assurance.

Oncological outcome of vocal cord-only radiotherapy for cT1-T2 glottic laryngeal squamous cell carcinoma

PURPOSE

Early-stage glottic cancer can be treated with radiotherapy only. Modern radiotherapy solutions allow for individualized dose distributions, hypofractionation and sparing of organs at risk. The target volume used to be the entire voice box. This series describe the oncological outcome and toxicity of individualized vocal cord-only hypofractionated radiotherapy for early stage (cT1a-T2 N0).

METHODS

Retrospective cohort study with patients treated in a single center between 2014 and 2020.

RESULTS

A total of 93 patients were included. Local control rate was 100% for cT1a, 97% for cT1b and 77% for cT2. Risk factor for local recurrence was smoking during radiotherapy. Laryngectomy-free survival was 90% at 5 years. Grade III or higher late toxicity was 3.7%.

CONCLUSION

Vocal cord-only hypofractionated radiotherapy appears to be oncologically safe in early-stage glottic cancer. Modern, image-guided radiotherapy led to comparable results as historical series with very limited late toxicity.