Patterns of Failure in Patients With Head and Neck Squamous Cell Carcinomas of Unknown Primary Treated With Chemoradiotherapy.

BACKGROUND: To evaluate the patterns of failure in patients treated for head and neck carcinoma of unknown primary and to discuss treatment practices concerning radiotherapy target volumes definition and dose prescription. METHODS: Eleven patients presenting a locoregional recurrence after head and neck carcinoma of unknown primary treatment with curative-intent radiochemotherapy performed between 2007 and 2017 in the departments of radiation oncology of 2 French cancer institutes. Images of the computed tomography scan or the magnetic resonance imaging performed at the time of the recurrence were fused with those of the simulation computed tomography scan to delimit a volume corresponding to the recurrence and to define the area of relapse compared to the volumes treated. RESULTS: Irradiation was unilateral in 6 cases and bilateral in 5 cases. The median time to onset of recurrence was 7.24 months (extreme 3-67.7 months). Six patients had only a neck node recurrence, 3 had a neck node and subsequent primary recurrence, and 1 had only a median subsequent primary recurrence. Only 1 patient had synchronous distance progression to local recurrence. All neck node recurrences were solitary and ipsilateral. The subsequent primary recurrences were in the oropharynx in 3 cases and in the contralateral oral cavity in one case. All neck node recurrences were into the irradiated volume. The subsequent primary recurrences were either within or in border of the irradiated volumes. The median of the mean dose, received by neck node recurrences, was 69.9 Gy and that of the mean dose, minimum dose, maximum dose, and dose received by 95% of the volume of recurrence was 66.7 Gy. For the primary relapses, the median of the mean dose was 52.1 Gy and that of the mean dose, minimum dose, maximum dose, and dose received by 95% of the volume of recurrence was 39.9 Gy. CONCLUSIONS: All local nodal recurrences occurred at sites that received high radiotherapy doses and doses received by sites of eventual failure did not vary significantly from sites that remain in control.

[Adaptive radiotherapy for nasopharyngeal carcinomas: Where are we?] / La radiothérapie adaptative des carcinomes nasopharyngés : où sommes-nous ?

Modern high-precision radiotherapy techniques have recently incorporated the notion of anatomical variations of the patient during treatment and have tried to adapt the treatment planning to them. Adaptive radiotherapy for nasopharyngeal tumors is starting to prove its benefit nowadays. His interest is constantly being evaluated. The variations encountered during the treatment are both geometric and dosimetric. They are represented by a reduction in the macroscopic tumors volume, a change in its position and a consequent dosimetric impact. The changes also concern organs at risk with a reduction of glandular structure volumes, and a different position which increases their doses. Delivered doses to noble structures (brainstem and spinal cord) may also increase. However, difficulties are encountered in its realization. There is a problem to perfectly reproduce the patient position during the second acquisition, which impacts the fusion quality between the two CT scans. This generates an imprecision in the definition of the same treatment isocentre on the second scanner. Also, there is a difficulty in accumulated doses calculation. The indication of adaptive radiotherapy remains a subject of controversy. It should be proposed for a subgroup of patients who could benefit from this new strategy. We present here an update on the state of the art of adaptive radiotherapy for nasopharyngeal cancer.

Dosimetric impact on changes in target volumes during intensity-modulated radiotherapy for nasopharyngeal carcinoma.

BACKGROUND AND PURPOSE: To assess anatomic changes during intensity modulated radiotherapy (IMRT) for nasopharyngeal carcinoma (NPC) and to determine its dosimetric impact. PATIENTS AND METHODS: Twenty patients treated with IMRT for NPC were enrolled in this study. A second CT was performed at 38 Gy. Manual contouring of the macroscopic tumor volumes (GTV) and the planning target volumes (PTV) were done on the second CT. We recorded the volumes of the different structures, D98 %, the conformity, and the homogeneity indexes for each PTV. Volume percent changes were calculated. RESULTS: We observed a significant reduction in tumor volumes (58.56 % for the GTV N and 29.52 % for the GTV T). It was accompanied by a significant decrease in the D98 % for the 3 PTV (1.4 Gy for PTV H, p = 0.007; 0.3 Gy for PTV I, p = 0.03 and 1.15 Gy for PTV L, p = 0 0.0066). In addition, we observed a significant reduction in the conformity index in the order of 0.02 (p = 0.001) and 0.01 (p = 0.007) for PTV H and PTV I, respectively. The conformity variation was not significant for PTV L. Moreover, results showed a significant increase of the homogeneity index for PTV H (+ 0.03, p = 0.04) and PTV L (+ 0.04, p = 0.01). CONCLUSION: Tumor volume reduction during the IMRT of NPC was accompanied by deterioration of the dosimetric coverage for the different target volumes. It is essential that a careful adaptation of the treatment plan be considered during therapy for selected patients.

[Neoadjuvant chemotherapy with concurrent chemoradiotherapy in the treatment of nasopharyngeal cancer: Southern Tunisian experience]. / La chimiothérapie néoadjuvante associée à la chimioradiothérapie concomitante dans le traitement du cancer du nasopharynx : expérience du Sud-Tunisien.

PURPOSE: A retrospective study to evaluate the efficacy and safety of the addition of neoadjuvant chemotherapy to concurrent chemoradiotherapy in the treatment of nasopharyngeal carcinoma. PATIENTS AND METHODS: Data from 62 patients treated for non-metastatic nasopharyngeal carcinoma were analyzed by comparing two groups of patients: a first group of 32 patients treated with 3 cycles of neoadjuvant chemotherapy based on docetaxel, cisplatin and 5-fluoro-uracil every 21 days followed by concurrent chemoradiotherapy (weekly cisplatin 40mg/m2 with radiotherapy 70Gy, 2Gy per session, 5 sessions per week) and a second group of 30 patients treated with the same concurrent chemoradiotherapy. RESULTS: After a median follow-up of 53.5 months, neoadjuvant chemotherapy showed a significant reduction in the rate of a distant metastatic relapses (3.3% vs. 10%, P=0.03). No significant difference in disease-free survival at 5 years (65.6% vs. 68.8%, P=0.46) or overall survival at 5 years (68.8% vs. 73.3%, P=0.46) was noted between the two groups. Induction chemotherapy was associated with febrile neutropenia of 15.6%. During concurrent chemoradiotherapy, hematological complications were greater in the first chemotherapy group (53% vs. 33%). CONCLUSION: Induction chemotherapy by docetaxel, cisplatin and 5-fluoro-uracil is a safe and effective option in the treatment of nasopharyngeal carcinoma. A better definition of high risk of relapse group would optimize the indications of this chemotherapy in the therapeutic arsenal.