CYBERKNIFE STEREOTACTIC RADIOTHERAPY FOR SPINAL TUMORS

OBJECTIVE

For para- and intraspinal tumors, precise spinal cord delineation is critical for CyberKnife (Accuray, Inc., Sunnyvale, CA) stereotactic radiotherapy. We evaluated whether computed tomographic (CT) myelography is superior to magnetic resonance imaging (MRI) for accurate spinal cord delineation. Treatment parameters and short-term outcome and toxicity are also presented.

METHODS

The planning CT scan, the gadolinium-enhanced, T1-weighted, 3-dimensional (3D) fast imaging employing steady-state acquisition MRI scan, and the CT myelogram were fused before volume-of-interest delineation. The planning target volume margin was less than 1 mm using the Xsight Spine tracking system (Accuray). We present data from 11 heavily pretreated patients who underwent CyberKnife stereotactic radiosurgery between November 2006 and January 2008.

RESULTS

Spatial resolution was 0.46 and 0.93 mm/pixel for CT myelography and 3D-fast imaging employing steady-state acquisition MRI, respectively. The contrast between cerebrospinal fluid and spinal cord was excellent with CT myelography. A transient postmyelography headache occurred in 1 patient. The mean gross tumor volume was 51.1 mL. The mean prescribed dose was 34 Gy in 4 fractions (range, 2–7 fractions) with 147 beams (range, 79–232 beams) to the 75% reference isodose line (range, 68–80%), covering 95% (range, 86–99%) of the gross tumor volume with a mean conformity index of 1.4 (range, 1.1–1.8). No short-term toxicity on the spinal cord was noted at 1- to 6-months of follow-up.

CONCLUSION

CT myelography was more accurate for spinal cord delineation than 3D-fast imaging employing steady-state acquisition MRI (used for its myelographic effect), particularly in the presence of ferromagnetic artifacts in heavily pretreated patients or in patients with severe spinal compression. Because other MRI sequences (T2 and gadolinium-enhanced T1) provide excellent tumor characterization, we suggest trimodality imaging for spinal tumor treatment to yield submillimetric delineation accuracy. Combined with CyberKnife technology, CT myelography can improve the feasibility of dose escalation or reirradiation of spinal tumors in selected patients, thereby increasing local control while avoiding myelopathy. Further follow-up and prospective studies are warranted.

[Feasibility and efficacy of cyberknife radiotherapy for lung cancer: early results]

PURPOSE

High-dose robotic stereotactic irradiation can be achieved with high precision using the CyberknifeM system equipped with the Synchrony respiratory tracking device. Cyberknife irradiation can overcome some limitations of conventional radiotherapy including errors due to breathing motion and patient setup. High dose levels are of interest for tumours that have shown a dose-response relationship including lung tumours. We reviewed the treatments and outcomes for the first French patients with lung tumours treated at the Cyberknife centre of Nice.

PATIENTS AND METHODS

Thirty four patients were treated between November 2006 and November 2007 at the Cyberknife centre of Nice, Centre Lacassagne, France. Thirty had untreated primary lung cancer, 4 had colorectal metastasis to the lung. We evaluated the feasibility and reliability of fiducial placement, toxicity and early outcomes. Objective tumour response was assessed on thoracic CT scan every three months.

RESULTS

There was no grade 3-4 toxicity. Toxicity (11%) mainly consisted of grade 1-2 asthenia. Crude overall tumour response rate was 96% for all assessable patients and 91% at 3 and 6 months, respectively. The use of one fiducial ensured minimal toxicity (no grade III pneumothorax) while allowing reliable tumour tracking as shown by the low infield failure rate (no geographic miss). Diagnostic procedure was performed during fiducial placement when required.

CONCLUSION

Early toxicity and tumour control rates from this population suggest that the use of a unique fiducial for a Cyberknife treatment was safe and effective for the treatment of selected primary and secondary lung tumours. This strategy is corroborated by similar control rates in the literature. Longer follow-up are awaited.

Outcomes after radiotherapy for basaloid squamous cell carcinoma of the head and neck: a case-control study

BACKGROUND

Basaloid squamous cell carcinoma (BSCC) is an uncommon, high-grade variant of squamous cell carcinoma (SCC) of the head and neck. Its poorer prognosis compared with common SCC remains controversial. The authors investigated the outcomes of patients with BSCC who received radiotherapy and compared them with the outcomes of patients with SCC.

METHODS

From 1994 to 2004, 1007 patients received radiotherapy for head and neck carcinoma with lymph node involvement. The histologic types consisted of 51 BSCC, 431 poorly differentiated SCC (PSCC), and 525 well or moderately differentiated SCC (WMSCC). A case-control analysis was performed with BSCC matched against both PSCC and WMSCC to compare disease-control and survival rates.

RESULTS

Patients with BSCC received treatment modalities similar to those received by patients with SCC: They received induction chemotherapy (12%) or concurrent chemotherapy (33%), and a median radiation dose of 70 Gray. Posttreatment viable tumor was present in 44%, 13%, and 28% of neck dissection specimens from patients with BSCC, PSCC, and WMSCC, respectively. The 5-year disease-free survival rates (63%, 77%, and 76%, respectively) and overall survival rates (85%, 70%, and 71%, respectively) demonstrated no statistically significant differences for BSCC, PSCC, or WMSCC, respectively.

CONCLUSIONS

In this study, a poorer prognosis could not be demonstrated for irradiated patients with BSCC compared with either PSCC or WMSCC. All patients in this study had positive lymph node status, and the majority of patients (84%) had oropharyngeal cancer. The BSCC cohort did have a relatively high rate of viable tumor in their posttreatment neck dissections, and they had a relatively high rate of distant disease. On the basis of the high rate of lung metastases and the possibility of efficient salvage, the authors recommend obtaining a chest computed tomography scan during initial staging and follow-up.

Modeling of salivary production recovery after radiotherapy using mixed models: determination of optimal dose constraint for IMRT planning and construction of convenient tools to predict salivary function

PURPOSE

The mathematical relationship between the dose to the parotid glands and salivary gland production needs to be elucidated. This study, which included data from patients included in a French prospective study assessing the benefit of intensity-modulated radiotherapy (RT), sought to elaborate a convenient and original model of salivary recovery.

METHODS AND MATERIALS

Between January 2001 and December 2004, 44 patients were included (35 with oropharyngeal and 9 with nasopharyngeal cancer). Of the 44 patients, 24 were treated with intensity-modulated RT, 17 with three-dimensional conformal RT, and 2 with two-dimensional RT. Stimulated salivary production was collected for </=24 months after RT. The data of salivary production, time of follow-up, and dose to parotid gland were modeled using a mixed model. Several models were developed to assess the best-fitting variable for the dose level to the parotid gland.

RESULTS

Models developed with the dose to the contralateral parotid fit the data slightly better than those with the dose to both parotids, suggesting that contralateral and ipsilateral parotid glands are not functionally equivalent even with the same dose level to the glands. The best predictive dose-value variable for salivary flow recovery was the volume of the contralateral parotid gland receiving >40 Gy.

CONCLUSION

The results of this study show that the recommendation of a dose constraint for intensity-modulated RT planning should be established at the volume of the contralateral parotid gland receiving >40 Gy rather than the mean dose. For complete salivary production recovery after 24 months, the volume of the contralateral parotid gland receiving >40 Gy should be <33%. Our results permitted us to establish two convenient tools to predict the saliva production recovery function according to the dose received by the contralateral parotid gland.

Skin metastasis of head and neck carcinoma predictive for dismal outcome

A 64-year-old female with locally advanced oropharyngeal carcinoma presented with an innocuous appearing macule on the abdomen. The lesion rapidly enlarged over 2 weeks into an inflammatory 5 cm fleshy nodule that was diagnosed as squamous cell carcinoma (SCC) and was found to overexpress epidermal growth factor receptor (EGFR). A fatal outcome occurred 3 months after the initial diagnosis of cancer, in spite of chemotherapy and treatment with EGFR inhibitors (cetuximab). Cutaneous metastases occur in 10 percent of squamous cell carcinomas of the head and neck. Contiguous cutaneous metastases in the head and neck areas are by far the most common. Conversely, isolated infradiaphragmatic cutaneous metastases are exceedingly rare and are associated with an aggressive clinical course. In a patient with cancer, the possibility of distant skin metastasis should be considered whenever new cutaneous nodules appear.

[Prostate specific antigen: utilization modalities and interpretation]

The prostate specific antigen test has become one of the most popular blood test. However, its result should be analyzed with caution due to physiologic variability. The PSA test is performed for prostate cancer (PC) screening or for post-treatment PC surveillance. According to the applied treatment (surgery or radiation therapy with or without hormonal therapy), PSA analysis can confirm biochemical control or relapse. New PSA data regarding the evolution of this biomarker during the surveillance (PSA doubling time and PSA velocity) are now important to consider in case of biochemical relapse.

Marked difference in cytochrome c oxidation mediated by HO(*) and/or O(2)(*-) free radicals in vitro

Cytochrome c (cyt c) is an electron carrier involved in the mitochondrial respiratory chain and a critical protein in apoptosis. The oxidation of cytochrome c can therefore be relevant biologically. We studied whether cytochrome c underwent the attack of reactive oxygen species (ROS) during ionizing irradiation-induced oxidative stress. ROS were generated via water radiolysis under ionizing radiation (IR) in vitro. Characterization of oxidation was performed by mass spectrometry, after tryptic digestion, and UV-visible spectrophotometry. When both hydroxyl and superoxide free radicals were generated during water radiolysis, only five tryptic peptides of cyt c were reproducibly identified as oxidized according to a relation that was dependent of the dose of ionizing radiation. The same behavior was observed when hydroxyl free radicals were specifically generated (N(2)O-saturated solutions). Specific oxidation of cyt c by superoxide free radicals was performed and has shown that only one oxidized peptide (MIFAGIK+16), corresponding to the oxidation of Met80 into methionine sulfoxide, exhibited a radiation dose-dependent formation. In addition, the enzymatic site of cytochrome c was sensitive to the attack of both superoxide and hydroxyl radicals as observed through the reduction of Fe(3+), the degradation of the protoporphyrin IX and the oxidative disruption of the Met80-Fe(3+) bond. Noteworthy, the latter has been involved in the conversion of cyt c to a peroxidase. Finally, Met80 appears as the most sensitive residue towards hydroxyl but also superoxide free radicals mediated oxidation.

Very Late Local Relapse of Ewing's Sarcoma of the Head and Neck treated with Aggressive Multimodal Therapy

Ewing's sarcoma's relapse rarely occurs more than two years after the initial diagnosis. We report the case of a 26-year-old man with a history of Ewing's sarcoma of the left maxillary sinus at the age of 10 who presented with a very late local relapse, 16 years after the first occurrence of disease. Ultimate control was achieved after multimodal therapy including surgery, high-dose chemotherapy, and radiotherapy. This report indicates that local relapses of Ewing's sarcoma can be treated with curative intent in selected cases.

Aggressive adenoid cystic carcinoma with asymptomatic spinal cord compression revealed by a "curtain sign"

The authors present a case of unusually aggressive adenoid cystic carcinoma of the head and neck. The patient presented with sciatica one year after initial diagnosis. She was otherwise asymptomatic. Complete work-up for bone involvement, included bone scan and MRI. The patient had painful osteolytic sacral metastasis and asymptomatic thoracic (T5) vertebral metastasis revealed by a typical curtain sign on MRI. The curtain sign, originally described by Trolard, is due to the displacement of the Trolard's membrane with the median ligament attaching the dura to the bone while there is a dorsal displacement and loosening of the posterior longitudinal ligament. The patient benefited from radiotherapy and did not develop respiratory distress, paraplegia or pain but died of liver metastases.

Combination of radiotherapy with EGFR antagonists for head and neck carcinoma

The introduction of biologically sound radiation fractionation regimens and combinations of radiotherapy with chemotherapy have gradually improved both the survival of patients with locally advanced head and neck squamous cell carcinoma (HNSCC) and the prospect of organ preservation. Long-term follow-up, however, has shown that some of the radiation-chemotherapy combinations are associated with increased late toxicity. This observation, in conjunction with advances in tumor biology, has led to the launch of investigations into molecular markers and targets for therapeutic interventions. Research on the epidermal growth factor receptor (EGFR)-mediated signaling pathway has enriched our understanding of the biology of HNSCC, in terms of carcinogenesis and cellular processes governing tumor response to therapy. The finding that the addition of an antibody-based inhibitor of the EGFR pathway to radiotherapy significantly improves locoregional control and overall survival rates in patients with locally advanced HNSCC, without increasing radiation-induced toxicity, has resulted in the growing acceptance of such combined regimens as a frontline therapy option for locally advanced HNSCC. Because such therapy has benefited only an additional 10%-15% of patients, studies are being undertaken to identify markers and mechanisms of resistance to EGFR antagonists that are essential for the further refinement of therapy. Overall, preclinical and clinical studies on EGFR have validated the concept that selective tumor radiation sensitization can be achieved by modulating a specific perturbed signaling pathway, and these studies have increased the enthusiasm for developing and investigating other novel agents targeting other cellular processes.

Conservative treatment of early glottic carcinomas with exclusive radiotherapy

BACKGROUND

Early glottic carcinomas can be treated with radiotherapy or surgery with similar local control rates but with better functional results with radiotherapy. The aim of this study was to analyze the results of our experience of exclusive radiotherapy.

PATIENTS AND METHODS

From 1975 to 2001, 155 patients with Tis, T1 and T2 glottic carcinomas were treated with exclusive radiotherapy. Prognostic factors of survival, local control and larynx-preservation rates were analyzed in uni and multivariate analyses.

RESULTS

Median prescribed dose was 65 Gy in 44 days. Overall survival was 75% for the whole group, 75% for Tis, 85% for T1a, 72% for T1b, 59% for T2. Specific survival was 88% for the whole group, 75% for Tis, 94% for T1a, 90% for T1b, 69% for T2. Disease-free survival was 68% for the whole group, 75% for Tis, 77% for T1a, 51% for T1b, 58% for T2. Laryngeal preservation rate was 85% (133/155). Twenty-nine (29/155, 18%) patients developed a local relapse within 31 months. Out of the 10/86 (12%) T1a-Tis relapses, 7/10 patients underwent total laryngectomy and 79/86 larynx were preserved (92%). Out of the 8/22 (36%) T1b relapses, 4/8 patients underwent total laryngectomy. Out of the 11/47 (23%) T2 relapses, 8/11 patients underwent total laryngectomy. Increased overall treatment time, tumor stage, sub-glottis extension were associated with poorer local control. Second malignancies remain a major problem in the outcome of this population.

CONCLUSION

Radiotherapy remains an efficient option in the treatment of early glottic carcinomas providing a high local control rate with excellent functional results in laryngectomy-free patients. This strategy should be discussed according to the tumor stage, feasibility of conservative surgery and patient's preferences.

Sensitivity and specificity of thallium-201 scintigraphy for the diagnosis of malignant vertebral fractures

OBJECTIVE

To evaluate the accuracy of thallium-201 (201TI) scintigraphy in distinguishing a benign from a malignant recent non-traumatic vertebral fracture.

METHODS

STUDY DESIGN--Single center, prospective study. PARTICIPANTS--Patients hospitalized for a recent non-traumatic vertebral fracture. EVALUATION--Usual clinical, laboratory and radiological assessment; 201TI vertebral scintigraphy: patients were injected with iv 3 mCi 201TI. Early and delayed images of the fractured vertebra were obtained. DATA ANALYSIS--(1) Two examinators, unaware of the other findings, rated the images as hyperfixation or not of the fractured vertebra; (2) the ratio (average count per pixel of the fractured vertebra/normal adjacent vertebrae) were calculated. The FINAL DIAGNOSIS was established on the result of vertebral biopsy or on follow-up.

RESULTS

Twenty-one patients were included. The final diagnosis was a benign vertebral fracture in 14 patients and a malignant vertebral fracture in 7. The sensitivity, specificity, positive and negative predictive values for a malignant fracture on early 201TI vertebral scintigraphy images were 28.6, 92.9, 66.6, and 72.2%, respectively, and on delayed images were 28.6, 100, 100, and 73.7%, respectively. The ratio of lesioned over normal tissue was not increased in malignant, compared with benign fractures.

CONCLUSION

The weak sensitivity does not support the wide use of 201TI bone scintigraphy to distinguish a benign from a malignant recent non traumatic vertebral fracture. However, the high specificity suggests that such evaluation might be proposed prior to vertebral biopsy in some difficult cases.

[High dose rate brachytherapy: a potentially curative treatment for small invasive T1N0 endobronchial carcinoma and carcinoma in situ]

INTRODUCTION

High dose rate brachytherapy (HDR-BT) is an option for treatment of small invasive endobronchial carcinoma and carcinoma in situ. This retrospective study describes the results of 33 consecutive patients treated with curative intent and followed up for more than one year.

METHODS

Between July 1994 and October 1999, 35 tumours were treated with HDR-BT alone using a standard protocol delivering 6 fractions of 5 Gy delivered across 1cm from the catheters over 3 to 6 weeks. In 31 patients, surgical treatment was ruled out because of histology (in situ carcinoma), history of pneumonectomy or significant co-morbidity. Two patients were treated for positive resection margins following pneumonectomy. All the tumours were Tis or T1 N0.

RESULTS

The locations of tumours were: trachea - 2, main bronchus - 5, lobar - 20, and segmental - 8. Only one catheter was needed in 15 cases, 2 in 13 cases, 3 in 6 cases and 4 in 1 case. The median follow-up was 17 months (range, 5-53 months). The recurrence-free rate was 94.3% at 2 months and 86.2% at 6 months after the treatment. 15 patients (45.5%) developed local recurrence at a median time of 9 months. Three patients developed metastases. The 1-year and 2-year overall survival rate were 71.4% and 53.8% respectively and specific survival rates were 69.4% and 59%. One patient developed an acute pneumothorax, and late complications included 6 infections and 12 bronchial stenoses. There were no episodes of haemoptysis nor lethal complications.

CONCLUSIONS

With strict selection criteria, HDR-BT can be a curative treatment for early invasive or in situ endobronchial carcinoma without serious toxicity. It is therefore a good alternative treatment with curative intent for inoperable patients.

[Cutaneous manifestations of the leukemia-lymphoma of HTLV 1: apropos of 1 case]

Human T-cell lymphotropic virus type 1 (HTLV-1) is a retrovirus implicated in adult T-cell leukemia/lymphoma characterized by proliferation of infected mature auxiliary T-cell lymphocytes. Cutaneous manifestations of T-cell leukemia/lymphoma are inconsistent and variable findings. In some patients, skin lesions are the presenting symptoms that lead to diagnosis and in others they are secondary occurrences. This report describes a case of T-cell leukemia/lymphoma associated with serologically documented HTLV-1 infection in a 27-year-old black man from Surinam. Manifestations were low-grade at the time of diagnosis and became tumor-like at the end stage of the disease. At the time of presentation, examination revealed plaques of infiltrated scaly erythrematous lesions scattered over the entire body. One year later the patient exhibited xerodema and variable-sized subcutaneous tumor-like nodules. This case illustrates the wide range of cutaneous manifestations that can be found in association with cutaneous T-cell lymphoma due to HTLV-1.