Effect of bilateral supraclavicular postoperative radiotherapy in middle and lower thoracic esophageal carcinoma

AIM: To evaluate whether postoperative radiotherapy is an alternative to neck lymph node surgery and if it provides a survival benefit for those receiving two-field, chest and abdomen, lymphadenectomy.

METHODS: A total of 530 cases with middle and lower thoracic esophageal carcinoma in our hospital from January 2008 to April 2009 were selected and analyzed, of which 219 cases received right chest, upper abdominal incision Ivor-Lewis surgery and simultaneously underwent mediastinal and abdominal two-field lymphadenectomy. If regional lymph node metastasis occurred within the recurrent laryngeal nerve, the patients would receive bilateral supraclavicular radiotherapy (DT = 5000cGy) to be adopted at postoperative 4-5 wk (Group A) or cervical lymphadenectomy at postoperative 3-4 wk (Group B). If there were no regional lymph node metastases within the recurrent laryngeal nerve, the patients only underwent two-field, chest and abdomen, lymphadenectomy (Group C).

RESULTS: In 219 cases who underwent two-field lymphadenectomy, 91 cases were diagnosed with regional lymph node metastasis within the recurrent laryngeal nerve. Of them, 48 cases received cervical radiotherapy, and 43 cases underwent staging lymphadenectomy; 128 patients were not given the follow-up treatment of cervical radiotherapy because there was no regional lymph node metastasis within the recurrent laryngeal nerve. Five-year survival rates in group A and B were 47% and 50%, respectively, with no statistical difference between them, and the rate in group C was 58%.

CONCLUSION: For patients with middle and lower thoracic esophageal carcinoma combined with lymph node metastasis within the recurrent laryngeal nerve, cervical radiotherapy can be a substitute for surgery and provide benefit.

Esophageal gel-shifting technique facilitating eradicative boost or reirradiation to upper mediastinal targets of recurrent nerve lymph node without damaging esophagus

We developed a new technique using hyaluronic gel injection as a spacer to safely move the esophagus away from the high-dose area during interstitial brachytherapy of a mediastinal target close to the esophagus. We percutaneously injected a high-molecular-weight hyaluronic gel mixed with contrast medium to create a space between the esophagus and the target during interstitial brachytherapy. We applied this technique to two cases of relapsed recurrent nerve lymph node metastasis from esophageal cancer: one refractory tumor after 50 Gy of radiotherapy, and one recurrence after mediastinal radiotherapy of total 64 Gy. We prescribed 20 Gy and 18 Gy in one fraction to each target, with calculated esophageal D2cc (the minimum dose to the most irradiated volume of 2 cc) of 4.0 Gy and 6.8 Gy, respectively. Calculated enhancement factor by gel shifting in equivalent dose was 2.69 and 2.34, respectively. In each patient, accumulated esophageal D1cc (minimum dose to the most irradiated volume of p cc. minimum dose to the most irradiated volume of 1 cc) was 74.4 Gy and 85.6 Gy without shifting, and 59.1 Gy and 37.6 Gy with shifting, respectively. There were no procedure-related complications. Four months after the brachytherapy, each tumor was remarkably diminished. No evidence of recurrences or late complications were observed 8 months and 9 months after the procedure, respectively. The esophageal gel-shifting technique may facilitate eradicative brachytherapy to upper mediastinal targets without damaging the esophagus, and can be used in conjunction with boost irradiation or reirradiation to overcome the problem of salvage failure.

Radiation-related vocal fold palsy in patients with head and neck carcinoma

OBJECTIVE

Recurrent laryngeal nerve damage is a rare complication after receiving conventional radiotherapy for treatment of head and neck cancers and will always be underestimated. The purpose of the present study was to focus on the prevalence of vocal cord paralysis after irradiation and the natural history in those patients.

MATERIAL AND METHOD

All patients who received more than 60 Gy radiation dose of convention radiotherapy for treatment of head and neck carcinoma from Phramongkutklao Hospital and Nation Cancer Institute of Thailand were recruited in the present study duringfollow-up period between May 2006-December 2007. The subjects had to have good mobility of bilateral vocal cords with no recurrence or persistent tumor before the enrollment. Baseline characteristic and the associated symptoms of the recurrent laryngeal nerve paralysis were recorded. Laryngeal examinations were done byfiberoptic laryngoscope and in suspicious cases; stroboscope and/or laryngeal electromyography were also performed. The vocal fold paralysis was diagnosed by reviewing recorded VDO by 2 laryngologist who were not involved in the present study.

RESULTS

70 patients; 51 male and 19female were recruited. 5 patients (7.14%) were diagnosed to have vocal cord paralysis and 2 patients (2.86%) were found to have vocal cord paresis confirmed by electromyography. Most of them were the patients with nasopharyngeal cancers (6/7) with the only one had oropharyngeal cancer (1/7). All of the paralysis/paresis was unilateral lesion; 4 on the left and 3 on the right side. The duration from the patients completed radiotherapy to the time of the diagnosis of vocal cord palsy was 14-35 months. The measure of agreement or Kappa value with 95% CI was 0.818 +/- 0.245. Associated symptoms of vocal cord palsy are hoarseness (100%), dysphagia (28.6%) and aspiration (28.6%).

CONCLUSION

A significant number of vocal fold palsy may occur in patients with head and neck carcinoma after receiving conventional radiotherapy. Subcutaneous fibrosis or compromised blood vessels at the skull base or the neck area may be important risk factors for development of the complications and further studies are need to solve the pathogenesis.

Response of laryngeal motoneurons to hyperventilation induced apnea in the rat

Central apnea is common in the premature newborn. To explain the upper airway findings in different clinical conditions characterized by central apnea, we made single unit recordings from laryngeal motoneurons during normal and hyperventilation. Posterior cricoarytenoid (n = 4) and cricothyroid (n = 4) motoneurons displayed an inspiratory pattern during normal ventilation and remained synchronous with phrenic nerve discharge (PND) during hyperventilation. Laryngeal constrictor motoneurons (LCon) displayed a post-inspiratory pattern during normal ventilation, but lost phasic activity during early hyperventilation (the period after the onset of hyperventilation but before cessation of PND; n = 12). There was a nearly linear relationship between the post-inspiratory activity and strength of PND. Six LCon motoneurons remained silent throughout hyperventilation, while the other six developed a tonic activity during cessation of PND. Further analysis suggested that the silent and tonic LCon motoneurons are likely to share a similar mechanism in their post-inspiratory pattern generation, but differ from each other in their responses to CO2 inputs. In addition, strong inhibition of the LCon tonic activity by the early return of PND could be an important factor in recovery following a period of apnea. Failure of this inspiratory inhibition to occur might explain certain clinical situations, where obstructive apnea supervenes following a period of central apnea.

Enhanced expression of neuronal nitric oxide synthase and phospholipase C-gamma1 in regenerating murine neuronal cells by pulsed electromagnetic field

Pulsed electromagnetic field (PEMF) has been shown to improve the rate of peripheral nerve regeneration. In the present study we investigated the expression of neuronal nitric oxide synthase (nNOS) and phospholipase C-gamma1 (PLC-gamma1) in regenerating rat laryngeal nerves during the exposure to PEMF after surgical transection and reanastomosis. Axons were found to regenerate into the distal stump nearly twice faster in PEMF-exposed animals than in the control. Consistently, motor function was better recovered in PEMF-treated rats. The expression of nNOS and PLC-gamma1 was highly enhanced in the regenerated nerves.

Permanent iatrogenic vocal cord paralysis after I-131 therapy: a case report and literature review

A patient who underwent I-131 therapy for a solitary toxic thyroid nodule subsequently experienced vocal cord paralysis, a rare complication. The patient was examined because of hoarseness 1 week after treatment. Indirect laryngoscopy at the time confirmed right vocal cord paralysis. When the examination was repeated in 6 months, no improvement was noted; vocal cord paralysis was then declared permanent. Surprisingly, 11 months after the onset of symptoms, the patient observed improvement in her voice. At 14 months, she experienced complete vocal recovery. However, a computed tomography performed after this showed that her right vocal cord paralysis was unresolved. The apparent complete recovery of her voice is believed to be a result of adaptive compensatory mechanisms. Patients who recover from hoarseness after injury to the recurrent laryngeal nerve should have cord function documented by indirect laryngoscopy or other means before the physician performs a procedure that could harm the contralateral nerve, because damage to this nerve could result in devastating consequences.

[Esophagomediastinal fistula and recurrent laryngeal nerve paralysis after radiotherapy of Hodgkin's disease]

The case of a female patient 21 years old at the time of diagnosis is reported. The patient suffered from stage IV Hodgkin's disease of the nodular sclerotic type with head and neck manifestations in cervical lymph nodes and in the esophagus. After radiotherapy; she suffered from an esophageal/mediastinal fistula and unilateral paralysis of the recurrent laryngeal nerve. Fifteen years later, there are no signs of recurrent tumor growth or a secondary neoplasm. Dysphonia was ameliorated by speech therapy, and surgery was not necessary.