Radiotherapy for T1a glottic cancer: the influence of smoking cessation and fractionation schedule of radiotherapy.

The objective of the presented study is to report on retrospectively collected data on long-term outcome and toxicity and prospective assessment of quality of life (QoL) and Voice-Handicap Index (VHI) of patients with T1a glottic cancer treated with radiotherapy. Between 1985 and 2011, 549 patients were treated. Endpoints were local control (LC), toxicity, QoL and VHI. After a median follow-up of 93 months, the actuarial rates of LC were 91, and 90 % at 5- and 10-years, respectively. Continuing smoking (p < 0.001) and anaemia (p = 0.02) were significantly correlated with poor LC on univariate analysis and fractionation schedule did not show significant correlation (p = 0.08). On multivariate analysis, only continuing smoking retained significance (p = 0.001). These patients had also significantly increased incidence of second primary tumour and lower overall survival rates. The incidence of grade ≥2 late xerostomia and dysphagia were 10 and 6 %, respectively. Slight and temporary deterioration of QoL-scores was reported. The scores on the EROTC-QOL-H&N35 dysphagia and xerostomia at 24 months were -2 and -3, compared to baseline, respectively. VHI improved significantly from 34 at baseline to 21 at 24 months. Patients who continued smoking had significantly worse VHI. In conclusion, excellent outcome with good QoL and VHI were reported. Patients who continued smoking after radiotherapy had significantly poor LC and worse VHI. The current study emphasizes the importance of smoking cessation and the non-inferiority of hypofractionated schemes in terms of outcome and VHI. At our institution, phase II study is going to evaluate the role of single vocal cord irradiation with high fraction dose.

Risk model and nomogram for dysphagia and xerostomia prediction in head and neck cancer patients treated by radiotherapy and/or chemotherapy.

In our randomized trial on hyperbaric oxygen (HBO), it was shown that HBO could reduce dysphagia and xerostomia, which are frequently encountered after (chemo-) radiotherapy (RT) and/or surgery for head and neck cancer (HNC). A risk model and nomogram are developed to select those patients who most likely will respond to HBO treatment. A total of 434 HNC patients treated from 2000 to 2008 were analyzed and filled out the EORTC QLQC-30 and H&N35 questionnaires. Age, gender, chemotherapy, T and N stages, site, radiotherapy technique, RT boost, surgery of the primary tumor and neck, bilateral RT, and dose were analyzed in a statistical model. The discriminative value of the model was evaluated based on receiver operating characteristics (ROC), the area under the curve (AUC), sensitivity, specificity, and proportion of correctly classified measures. Significant factors in predicting swallowing problems are age, follow-up duration, tumor site, chemotherapy, surgery of the primary tumor and neck, and dose. For dry mouth, the significant factors are age, gender, tumor site, N stage, chemotherapy, and bilateral irradiation. For dysphagia and xerostomia, the area under the ROC curve is 0.7034 and 0.7224, respectively, with a specificity of 89/77%, sensitivity of 27/58%, and a positive predictive value of 83/67% for dysphagia and xerostomia, respectively. The developed predictive risk model could be used to select patients for costly hyperbaric oxygen treatment to prevent or reduce severe late side effects of HNC treatment. Our model serves as a guideline for the Department of Radiation Oncology to reduce costs by excluding patients not amenable to hyperbaric oxygen protocols. The nomogram presented is a useful tool for clinicians in assessing patient risks when deciding on follow-up strategies (e.g., hyperbaric oxygen treatment) after RT or surgery for HNC.

Single vocal cord irradiation for early-stage glottic cancer: Excellent local control and favorable toxicity profile.

OBJECTIVE: To validate the earlier reported promising oncologic outcomes and favorable toxicity profile following single vocal cord irradiation (SVCI) in an expanded cohort of patients with early-stage glottic cancer treated at our institute with longer follow-up time. MATERIALS AND METHODS: Between February 2011 and January 2020, 111 consecutive patients with early-stage glottic cancer were treated with SVCI to the whole involved vocal cord (58.08 Gy, given in 16 fractions of 3.63 Gy). Setup verification was done using cone-beam CT, prior to each fraction. The endpoints were local control (LC), overall survival (OS), grade ≥ 3 toxicity and voice quality assessment using voice-handicap index (VHI) questionnaires. RESULTS: Median follow-up was 41 months (range; 8-84). Two patients developed in-field local failure (LF). The 3- and 5-year LC rates were 99.1% and 97.1%, respectively. As both patients with LF were successfully salvaged with total laryngectomy, the 5-year ultimate LC-rates was 99%. The 5-years OS was 80.6%. All patients finished treatment without any interruption. No patients developed acute grade ≥ 3 toxicity. Late grade 3 toxicity was reported in 7 patients (6.5%) out of 108 patients evaluable for late toxicity; 2 because of severe hoarseness and 5 because of laryngeal radionecrosis (4.5%). The 5-years laryngectomy-free survival was 98.1%. The VHI-scores improved over time, only 22% of patients had VHI > 30 at 3-years post-radiotherapy, compared to 38% at baseline. CONCLUSIONS: Local control rate and laryngectomy-free survival of SVCI are excellent with favorable toxicity profile and good VHI-score. These results validate our early results.

Class solution for inversely planned permanent prostate implants to mimic an experienced dosimetrist.

The purpose of this paper is to present a method for the selection of inverse planning parameters and to establish a set of inverse planning parameters (class solution) for the inverse planning included in a commercial permanent prostate implant treatment planning system. The manual planning of more than 750 patients since 1996 led to the establishment of general treatment planning rules. A class solution is tuned to fulfill the treatment planning rules and generate equivalent implants. For ten patients, the inverse planning is compared with manual planning performed by our experienced physicist. The prostate volumes ranged from 17 to 51 cc and are implanted with low activity 1-125 seeds. Dosimetric indices are calculated for comparison. The inverse planning needed about 15 s for each optimization (400 000 iterations on a 2.5 GHz PC). In comparison, the physicist needed about 20 min to perform each manual plan. A class solution is found that consistently produces dosimetric indices equivalent or better than the manual planning. Moreover, even with strict seed placement rules, the inverse planning can produce adequate prostate dose coverage and organ at risk protection. The inverse planning avoids implant with seeds outside of the prostate and too close to the urethra. It also avoids needles with only one seed and needles with three consecutive seeds. This reduces the risk of complication due to seed misplacement and edema. The inverse planning also uses a smaller number of needles, reducing the cause of trauma. The quality of the treatment plans is independent of the gland size and shape. A class solution is established that consistently and rapidly produces equivalent dosimetric indices as manual planning while respecting severe seed placement rules. The class solution can be used as a starting point for every patient, dramatically reducing the time needed to plan individual patient treatments. The class solution works with inverse preplanning, intraoperative inverse preplanning, and intraoperative real-time planning. This technology is not intended to replace the physicist but to accelerate the planning process, making intraoperative treatment planning more effective.

Inter- and Intrafraction Target Motion in Highly Focused Single Vocal Cord Irradiation of T1a Larynx Cancer Patients.

PURPOSE: The purpose of this study was to verify clinical target volume--planning target volume (CTV-PTV) margins in single vocal cord irradiation (SVCI) of T1a larynx tumors and characterize inter- and intrafraction target motion. METHODS AND MATERIALS: For 42 patients, a single vocal cord was irradiated using intensity modulated radiation therapy at a total dose of 58.1 Gy (16 fractions × 3.63 Gy). A daily cone beam computed tomography (CBCT) scan was performed to online correct the setup of the thyroid cartilage after patient positioning with in-room lasers (interfraction motion correction). To monitor intrafraction motion, CBCT scans were also acquired just after patient repositioning and after dose delivery. A mixed online-offline setup correction protocol ("O2 protocol") was designed to compensate for both inter- and intrafraction motion. RESULTS: Observed interfraction, systematic (Σ), and random (σ) setup errors in left-right (LR), craniocaudal (CC), and anteroposterior (AP) directions were 0.9, 2.0, and 1.1 mm and 1.0, 1.6, and 1.0 mm, respectively. After correction of these errors, the following intrafraction movements derived from the CBCT acquired after dose delivery were: Σ = 0.4, 1.3, and 0.7 mm, and σ = 0.8, 1.4, and 0.8 mm. More than half of the patients showed a systematic non-zero intrafraction shift in target position, (ie, the mean intrafraction displacement over the treatment fractions was statistically significantly different from zero; P<.05). With the applied CTV-PTV margins (for most patients 3, 5, and 3 mm in LR, CC, and AP directions, respectively), the minimum CTV dose, estimated from the target displacements observed in the last CBCT, was at least 94% of the prescribed dose for all patients and more than 98% for most patients (37 of 42). The proposed O2 protocol could effectively reduce the systematic intrafraction errors observed after dose delivery to almost zero (Σ = 0.1, 0.2, 0.2 mm). CONCLUSIONS: With adequate image guidance and CTV-PTV margins in LR, CC, and AP directions of 3, 5, and 3 mm, respectively, excellent target coverage in SVCI could be ensured.

Single Vocal Cord Irradiation: Image Guided Intensity Modulated Hypofractionated Radiation Therapy for T1a Glottic Cancer: Early Clinical Results.

PURPOSE: To report, from a retrospective analysis of prospectively collected data, on the feasibility, outcome, toxicity, and voice-handicap index (VHI) of patients with T1a glottic cancer treated by a novel intensity modulated radiation therapy technique developed at our institution to treat only the involved vocal cord: single vocal cord irradiation (SVCI). METHODS AND MATERIALS: Thirty patients with T1a glottic cancer were treated by means of SVCI. Dose prescription was set to 16 × 3.63 Gy (total dose 58.08 Gy). The clinical target volume was the entire vocal cord. Setup verification was done by means of an online correction protocol using cone beam computed tomography. Data for voice quality assessment were collected prospectively at baseline, end of treatment, and 4, 6, and 12 weeks and 6, 12, and 18 months after treatment using VHI questionnaires. RESULTS: After a median follow-up of 30 months (range, 7-50 months), the 2-year local control and overall survival rates were 100% and 90% because no single local recurrence was reported and 3 patients died because of comorbidity. All patients have completed the intended treatment schedule; no treatment interruptions and no grade 3 acute toxicity were reported. Grade 2 acute dermatitis or dysphagia was reported in only 5 patients (17%). No serious late toxicity was reported; only 1 patient developed temporary grade 2 laryngeal edema, and responded to a short-course of corticosteroid. The VHI improved significantly, from 33.5 at baseline to 9.5 and 10 at 6 weeks and 18 months, respectively (P<.001). The control group, treated to the whole larynx, had comparable local control rates (92.2% vs 100%, P=.24) but more acute toxicity (66% vs 17%, P<.0001) and higher VHI scores (23.8 and 16.7 at 6 weeks and 18 months, respectively, P<.0001). CONCLUSION: Single vocal cord irradiation is feasible and resulted in maximal local control rate at 2 years. The deterioration in VHI scores was slight and temporary and subsequently improved to normal levels. Long-term follow-up is needed to consolidate these promising results.

Single vocal cord irradiation: a competitive treatment strategy in early glottic cancer.

INTRODUCTION: The treatment of choice for early glottic cancer is still being debated; ultimately it relies on the functional outcome. This paper reports on a novel sparing 4D conformal technique for single vocal cord irradiation (SVCI). MATERIAL AND METHODS: The records of 164 T1a patients with SCC of the vocal cord, irradiated in the Erasmus MC between 2000 and 2008, were analyzed for local control and overall survival. The quality of life was determined by EORTC H&N35 questionnaires. Also the VHI (voice handicap index), and the TSH (thyroid stimulating hormone) blood levels, were established. On-line image guided SVCI, using cone beam CT or stereotactic radiation therapy (SRT) techniques, were developed. RESULTS: A LC rate at five-years of 93% and a VHI of 12.7 (0-63) was determined. It appeared feasible to irradiate one vocal cord within 1-2mm accuracy. This way sparing of the contralateral (CL) vocal cord and CL normal tissues, could be achieved. CONCLUSIONS: Given the accuracy (1-2mm) and small volume disease (CTV limited to one vocal cord), for the use of stereotactic RT techniques SVCI with large fraction sizes is currently being investigated in clinic. It is argued that hypofractionated SVCI can be a competitive alternative to laser surgery.