Results of fiberoptic endoscopic evaluation of swallowing vs. radiation dose in the swallowing muscles after radiotherapy of cancer in the oropharynx.

BACKGROUND AND PURPOSE: Dysphagia is a serious complaint but frequently underreported. This paper assesses for oropharyngeal cancer (OPC) the relationship between the dose received by the swallowing structures, and the findings of a fiberoptic endoscopic evaluation of the swallowing process (FEES). MATERIALS AND METHODS: Between 2000 and 2005, 60 of 67 OPC patients local-regionally NED for at least one year following treatment responded to three types of QoL questionnaires; i.e. Performance Status Scales, EORTC H&N35, and M.D. Anderson Dysphagia Inventory. Twenty-four patients agreed to the FEES procedure. The main swallowing muscles were delineated, with the mean dose per muscle calculated using the original 3D CT-based treatment plans. Regression analysis was performed between FEES variables and the doses in the different swallowing muscles and the dysphagia related questionnaires. RESULTS: A significant relationship was found between the results of FEES and the mean dose in the superior constrictor muscle (SCM). Some of the subjective dysphagia complaints were significantly correlated with the FEES variables in this retrospectively study. CONCLUSION: A higher dose in the SCM generally results in worsening of the findings obtained by the FEES examination.

Treatment techniques and site considerations regarding dysphagia-related quality of life in cancer of the oropharynx and nasopharynx.

PURPOSE: To assess the relationship for oropharyngeal (OP) cancer and nasopharyngeal (NP) cancer between the dose received by the swallowing structures and the dysphagia related quality of life (QoL). METHODS AND MATERIALS: Between 2000 and 2005, 85 OP and 47 NP cancer patients were treated by radiation therapy. After 46 Gy, OP cancer is boosted by intensity-modulated radiation therapy (IMRT), brachytherapy (BT), or frameless stereotactic radiation/cyberknife (CBK). After 46 Gy, the NP cancer was boosted with parallel-opposed fields or IMRT to a total dose of 70 Gy; subsequently, a second boost was given by either BT (11 Gy) or stereotactic radiation (SRT)/CBK (11.2 Gy). Sixty OP and 21 NP cancer patients responded to functional and QoL questionnaires (i.e., the Performance Status Scales, European Organization for Research and Treatment of Cancer H&N35, and M.D. Anderson Dysphagia Inventory). The swallowing muscles were delineated and the mean dose calculated using the original three-dimensional computed tomography-based treatment plans. Univariate analyses were performed using logistic regression analysis. RESULTS: Most dysphagia problems were observed in the base of tongue tumors. For OP cancer, boosting with IMRT resulted in more dysphagia as opposed to BT or SRT/CBK. For NPC patients, in contrast to the first booster dose (46-70 Gy), no additional increase of dysphagia by the second boost was observed. CONCLUSIONS: The lowest mean doses of radiation to the swallowing muscles were achieved when using BT as opposed to SRT/CBK or IMRT. For the 81 patients alive with no evidence of disease for at least 1 year, a dose-effect relationship was observed between the dose in the superior constrictor muscle and the "normalcy of diet" (Performance Status Scales) or "swallowing scale" (H&N35) scores (p < 0.01).

HDR prostate monotherapy: dosimetric effects of implant deformation due to posture change between TRUS- and CT-imaging.

HDR monotherapy for prostate cancer consists of four fractions. The first fraction is delivered with online TRUS-based treatment planning. For the last three fractions the treatment plan is based on a CT-scan acquired in between fractions 1 and 2. The patient position (high lithotomy, rectal US probe) during TRUS-guided catheter implantation and first fraction differs from the patient position in the CT-scan and the remaining three fractions (lowered legs, no TRUS probe). This study describes the effect of posture changes on dose distributions when a plan designed for the TRUS anatomy is applied to the CT-scan anatomy. The aim is to quantify dosimetrical errors that would result from skipping the use of a planning CT-scan, and rely for all fractions on the TRUS plan. Such a procedure would substantially reduce the involved workload, and would increase patient comfort. For three prostate cancer patients, images were acquired during TRUS-guided catheter implantation. Furthermore, a CT-scan (no US probe in rectum, different position of legs) was acquired and matched with the TRUS set. On both TRUS and CT, prostate, urethra and rectum were delineated and all catheters were traced. For each patient, an optimized treatment plan was designed using TRUS images and contours. Catheters with obtained dwell positions of the TRUS plan were transferred individually to the catheter positions in the CT. Changes in dose distribution due to relocation of catheters were evaluated using DVHs. For all patients the dose distributions changed significantly due to rearrangement of the catheters, having most impact on the urethra (maximum observed change: 32% volume receiving > or = 120% of the prescribed dose) and a reduction of PTV coverage (6-28%). Implant deformation when changing from TRUS patient set-up to CT set-up affected negatively the quality of optimized treatment plans. Inclusion of more patients in this study was planned, but because of the observed strong negative effects it is already concluded that the TRUS plan cannot be used for the last three fractions with a deviating patient set-up.

Brachytherapy versus surgery in carcinoma of tonsillar fossa and/or soft palate: late adverse sequelae and performance status: can we be more selective and obtain better tissue sparing?

PURPOSE: To report on the tumor control, adverse late normal tissue sequelae, and functional performance in patients with tonsillar fossa and/or soft palate (SP) tumors. The aim of the study is to validate the use of a more selective clinical target volume in conjunction with highly conformal radiotherapy (RT) techniques to better spare the surrounding normal tissues. METHODS AND MATERIALS: Between 1986 and 2001, T1-T3 tonsillar fossa/SP tumors were treated in the Erasmus Medical Center using external beam radiotherapy (EBRT) to 46 Gy in 2-Gy fractions to the primary tumor and neck, followed by brachytherapy (BT) to the primary. Neck dissection was performed for node-positive disease (BT group; 104 patients). If BT was not feasible, patients underwent surgery and postoperative RT (PORT) to a dose of 50-70 Gy in 2-Gy fractions (surgery group; 86 patients). Local control, regional control, disease-free survival, and overall survival were determined. Late side effects were scored using the Radiation Therapy Oncology Group criteria. Univariate and multivariate Cox regression analyses were performed for regional failure (RF), with the parameters gender, age, site, TN stage, modality, dose, and overall treatment time. Recurrences in the contralateral neck were also related to significant ipsilateral involvement of the base of tongue and/or involvement of the SP crossing the midline. To determine the performance status scale scores and degree of xerostomia, a survey was conducted among patients living with no evidence of disease and a minimum of 2 years of follow-up. For that purpose, a research nurse interviewed patients regarding eating in public, normalcy of diet, normalcy of speech, and xerostomia. RESULTS: The tumor control rates after BT vs. surgery at 5 years were 88% vs. 88% for local control; 93% vs. 85% for regional control; 57% vs. 52% for disease-free survival; 67% vs. 57% for overall survival; and 5% vs. 6% for RF. No patient had RF in the contralateral untreated N0 neck (0 of 14 vs. 0 of 15). Multivariate Cox regression analysis for RF was statistically significant for Stage T2 vs. T3 (hazard ratio 0.09) and for the dose to the neck >46 Gy (hazard ratio, 8.7; 95% confidence interval, 1.3-57.1). The significant late side effects in the BT group vs. surgery group were ulcer in 39% vs. 7% (p = 0.001) and trismus in 1% vs. 21% (p = 0.005). The performance status scale scores and response to questions regarding xerostomia for BT vs. surgery revealed no statistically significant differences for eating in public, normalcy of diet, normalcy of speech, and xerostomia. The mean visual analog score for xerostomia was 5.5 in the BT group vs. 6 in the surgery group. CONCLUSION: Excellent locoregional control was obtained in T1-T3 tonsillar fossa and/or SP tumors. The rate at 10 years was 84% (BT group) vs. 78% (surgery group). However, adverse late side effects were not negligible. In addition to modality-specific side effects (ulcer/trismus), both treatment groups were significantly affected by xerostomia. Only 6 recurrences (4%) were observed in the 149 electively treated contralateral necks, and no relapses were seen in the 29 untreated contralateral necks. We, therefore, suggest that it is not necessary to treat the contralateral neck, unless the tumor extends beyond the midline of the soft palate (uvula) or beyond the lateral one-third of the ipsilateral base of the tongue. Moreover, with the currently available CT-based neck level definitions, more conformal contours (i.e., tighter boundaries) around the clinical target volume can be designed. In this way, critical structures such as the temporomandibular joint and part of the pterygoid muscles can be avoided more easily. Also, when using highly conformal treatment techniques (e.g., intensity-modulated RT), one can further reduce the dose to the major salivary glands and oral mucosa. We believe these measures will lead to less trismus and less xerostomia.