Salvage treatment for persistent and recurrent T1-2 nasopharyngeal carcinoma by stereotactic radiosurgery

Gamma Knife Radiosurgery as a Salvage Treatment for Nasopharyngeal Carcinoma with Skull Base and Intracranial Invasion (T4b)

It is usually difficult to achieve good outcomes with salvage treatment for recurrent nasopharyngeal carcinoma (NPC) because of its deep-seated location, surrounding critical structures, and patient history of high-dose irradiation. Gamma Knife radiosurgery (GKS) is a treatment option for malignancies with skull base and intracranial invasion. We conducted a retrospective, observational, single-center study including 15 patients with recurrent NPC (stage T4b) involving the skull base and intracranial invasion, who underwent GKS as a salvage treatment. Patients were enrolled over 12 years. Per a previous study, the TNM classification T4b was subclassified into T4b1 and T4b2, defined as the involvement of the skull base or cavernous sinus with an intracranial extension of <5 mm and >5 mm, respectively. The effect of prognostic factors, including age, sex, survival period, magnetic resonance imaging (MRI) presentation, presence of other distant metastases, tumor volume, marginal dose, maximal dose, and Karnofsky Performance Status (KPS), on outcomes was analyzed. The patients with T4b1 NPC (p = 0.041), small tumor volume (p = 0.012), higher KPS (p < 0.001), and no other metastasis (p = 0.007) had better outcomes after GKS treatment, suggesting that it is a viable treatment modality for NPC. We also suggest that detailed brain imaging studies may enable the early detection of intracranial invasion.

Retreatment of Recurrent or Second Primary Head and Neck Cancer After Prior Radiation: Executive Summary of the American Radium Society® (ARS) Appropriate Use Criteria (AUC): Expert Panel on Radiation Oncology - Head and Neck Cancer

BACKGROUND

Re-treatment of recurrent or second primary head and neck cancers occurring in a previously irradiated field is complex. Few guidelines exist to support practice.

METHODS

We performed an updated literature search of peer-reviewed journals in a systematic fashion. Search terms, key questions, and associated clinical case variants were formed by panel consensus. The literature search informed the committee during a blinded vote on the appropriateness of treatment options via the modified Delphi method.

RESULTS

The final number of citations retained for review was 274. These informed five key questions, which focused on patient selection, adjuvant re-irradiation, definitive re-irradiation, stereotactic body radiation (SBRT), and re-irradiation to treat non-squamous cancer. Results of the consensus voting are presented along with discussion of the most current evidence.

CONCLUSIONS

This provides updated evidence-based recommendations and guidelines for the re-treatment of recurrent or second primary cancer of the head and neck.

Image-Guided Radiosurgery of Head and Neck Cancers

OBJECTIVES: Radiosurgery precisely delivers a single high dose or a few fractionated doses of radiation to a localized tumor via the stereotactic approach. Some head and neck sites are suitable for radiosurgery since there is minimal or no organ motion. The clinical studies were carried out to determine the accuracy of stereotactic radiosurgery and to demonstrate the effectiveness of radiosurgery in head and neck cancers.

MATERIALS AND METHODS: Thirteen patients were treated with either single-dose or fractionated radio-surgery to the tumor. All patients except one with cancer of the lip had received prior treatments including surgery, radiotherapy, and chemotherapy for the primary cancers. The dose ranged 12 to 18 Gy for single-dose radiosurgery and 30 Gy in 5 or 6 fractions twice a week for fractionated radiosurgery. Tumor localization was achieved via the stereotactic approach.

RESULTS: Accuracy of radiosurgery was within 1.5 mm. Despite the recurrent disease from previous heavy treatments, 9 patients (70%) showed a significant response (complete or >50% tumor reduction) to radiosurgery, and 3 patients had stable disease. Complete tumor response was achieved in 6 patients. All patients had excellent pain relief with functional and cosmetic preservation. There was no acute and subacute radiation toxicity detected clinically during the minimal follow-up of 6 months.

CONCLUSION: Image-guided radiosurgery is effective in achieving the local tumor control and pain relief. Radiosurgery provided excellent functional and cosmetic preservation with minimal complication. The results indicate the potential of radiosurgery in the treatment of recurrent and selected primary head and neck cancers. (Otolaryngol Head Neck Surg 2004;130:690-7.)

Frameless Stereotactic Radiosurgery for Recurrent Head and Neck Carcinoma

The aim of this study was to assess the feasibility and toxicity of stereotactic radiosurgery (CK-SRS) using the CyberKnife® Frameless Radiosurgery System (Accuray Inc., Sunnyvale, CA) in the management of recurrent squamous cell carcinoma of the head and neck region (SCCHN). Between November 2001 and February 2004, 22 patients with recurrent, previously irradiated SCCHN were treated with CK-SRS. The following endpoints were assessed post-CK-SRS: local control (LC), cause-specific survival (CSS), overall survival (OS), symptom relief, and acute and late toxicity. Kaplan-Meier survival analyses were used to estimate the LC, CSS, and OS rates. Clinical symptoms were graded as “improved,” “stable,” or “progressed” after CK-SRS. Acute and late toxicity were graded according to the National Cancer Institute Common Toxicity Criteria (CTC) scale, version 2.0. Seventeen patients were followed until their death. The median follow-up in the remaining five patients was 19 months (range 11–40 months). The median survival time for the entire cohort was 12 months from the time of CK-SRS. The 2-year LC, CSS, and OS rates were 26%, 26%, and 22%, respectively. After CK-SRS, symptoms were improved or stable in all but one patient who reported increasing pain. The treatment was well tolerated, with one case each of Grade 2 and 3 mucositis. There were no acute Grade 4 or 5 CTC toxicities. There were no late toxicities in this cohort. Frameless stereotactic radiosurgery for recurrent SCCHN is feasible and safe in the setting of high doses of prior irradiation. The majority of patients experienced palliation of disease without excess toxicity.

Salvage Surgery for Locally Recurrent Nasopharyngeal Carcinoma—A 10-Year Experience

OBJECTIVE: To evaluate the result of salvage surgery for patients with primary recurrence of nasopharyngeal carcinoma (NPC) after radiation therapy.

STUDY DESIGN AND SETTING: Prospective cohort at a tertiary referral center.

PATIENTS AND METHODS: Thirty-eight consecutive patients with primary recurrence of NPC after radiation failure underwent salvage surgery for curative intention via the facial translocation approach from July 1993 to December 2002. The follow-up time ranged from 2 to 88 months. Twelve patients with intracranial and skull base invasion needed a combined neurosurgical approach. Eight patients had additional postoperative radiation therapy.

RESULTS: The actuarial 3-year survival and local control rate was 60% and 72.8%, respectively. Ten (83.3%) of 12 patients with intracranial and skull base invasion achieved local control. There was no surgical mortality, and the morbidity rate was only 13.2%.

CONCLUSION AND SIGNIFICANCE: The results of this study reveal better outcome of salvage surgery than that of most published literature of reirradiation for recurrent NPC. With the adequate exposure provided by the facial translocation approach, an integrated concept of skull base surgery, and the collaboration of neurosurgeons, we can extend our surgical indications of salvage surgery and resect many advanced lesions with acceptable mortality and morbidity.

Cesium-131 brachytherapy in high risk and recurrent head and neck cancers: first report of long-term outcomes

Purpose

The feasibility and efficacy of re-irradiation using contemporary radiation techniques to treat recurrent head and neck cancer has been demonstrated but the role of brachytherapy is unclear. Here we describe the use of ¹³¹Cs brachytherapy with concurrent salvage surgery in 18 patients.

Material and methods

Eligible patients underwent maximal gross resection of the tumor with implantation of brachytherapy seeds delivering a minimum dose of 80 Gy to the tumor bed. Rates of overall survival, locoregional progression free survival, disease-free survival, and radiation-induced toxicity were analyzed.

Results

Retrospective Kaplan-Meier analysis shows median overall survival was 15 months and disease free survival was 12 months. Two patients developed grade 3 toxicity; all other complications were grade 1-2 with no grade 4 or 5 complications.

Conclusions

Compared to prior literature, our study shows comparable rates of survival with a decreased rate of radiation-induced toxicity.

Re-irradiation in head and neck cancers: an Indian tertiary cancer centre experience

Objective:

To explore the treatment outcomes of patients treated with re-irradiation for recurrent or second primary head and neck cancer.

Method:

An analysis was performed of 79 head and neck cancer patients who underwent re-irradiation for second primaries or recurrent disease from January 1999 to December 2011.

Results:

Median time from previous radiation to re-irradiation for second primary or recurrence was 53.6 months (range, 2.7–454.7 months). Median age at diagnosis of first primary was 54 years. Median re-irradiation dose was 45 Gy (range, 45–60 Gy). Acute grade 3 or worse toxicity was seen in 30 per cent of patients. Median progression-free survival for recurrent disease was 15.0 months (95 per cent confidence interval, 8.33–21.66). The following factors had a statistically significant, positive impact on progression-free survival: patient age of less than 50 years (median progression-free survival was 29.43, vs 13.9 months for those aged 50 years or older; p = 0.004) and disease-free interval of 2 years or more (median progression-free survival was 51.66, vs 13.9 months for those with less than 2 years disease-free interval).

Conclusion:

Re-irradiation of second primaries or recurrences of head and neck cancers with moderate radiation doses yields acceptable progression-free survival and morbidity rates.

Modified radical neck dissection for residual neck disease after radiotherapy of nasopharyngeal carcinoma

OBJECTIVE

Although radical neck dissection is proposed as a standard salvage procedure for the management of radiotherapy-resistant nasopharyngeal carcinoma of the neck, modified radical neck dissection may be appropriate for select patients. This study was designed to evaluate the efficacy of individualized neck dissections based on preoperative imaging studies and intraoperative exploration for the management of radiotherapy-resistant nasopharyngeal carcinoma of the neck.

METHODS

The study included 42 consecutive patients who failed radiotherapy or chemo-radiotherapy for nasopharyngeal carcinoma of the neck and underwent a total of 46 radical neck dissections or modified radical neck dissections. Selection of the proper type of neck dissection was based on preoperative imaging studies and intraoperative exploration. The patients' clinical features, pathologic characteristics, complications, and treatment outcome were estimated and analyzed.

RESULTS

Radical neck dissection and modified radical neck dissection were performed on 19 and 27 necks, respectively. Thirty-three necks (71.7%) had multiple node metastases. Nineteen necks (41.3%) had node metastases at two or more levels. The overall morbidity rate was 11.9%. The 5-year neck control rate (NCR) was 79.1% for 46 necks. The 5-year overall survival and disease free survival for 42 patients were 58.0% and 44.0%, respectively. No statistically significant differences were found in comparing OS, DFS, NCR between the MRND and RND groups.

CONCLUSIONS

Individualized neck dissection based on preoperative imaging studies and intraoperative exploration is appropriate for the management of radiotherapy-resistant nasopharyngeal carcinoma of the neck.

Stereotactic Body Radiotherapy (SBRT) for primary and recurrent head and neck tumors

Stereotactic Body Radiotherapy (SBRT) is increasingly used to treat a variety of head and neck tumors as a result of its highly conformal dose distributions and stereotactic spatial accuracy in delivery. Our experience and other previous reports have shown that SBRT is technically feasible, well-tolerated and compares favorably to other alternatives of salvage therapy in the management of patients with recurrent and/or previously irradiated head and neck cancers. Furthermore, it has the advantage of a shorter treatment schedule, greater compliance, and safe delivery in the outpatient setting. This affords an opportunity to introduce SBRT as a definitive treatment in select patients. This review presents an overview of the use of SBRT for managing head and neck tumors by highlighting the existing indications and the expanding role of SBRT in managing these patients.

The impact of tumor volume and radiotherapy dose on outcome in previously irradiated recurrent squamous cell carcinoma of the head and neck treated with stereotactic body radiation therapy

PURPOSE

To assess the effect of stereotactic body radiotherapy (SBRT) dose and tumor volume on outcomes in patients with recurrent, previously irradiated squamous cell carcinoma of the head and neck.

MATERIALS AND METHODS

A total of 96 patients with recurrent, previously irradiated squamous cell carcinoma of the head and neck were treated with SBRT using Cyberknife and Trilogy-intensity-modulated radiosurgery. Kaplan-Meier survival analyses were used to estimate locoregional control (LRC) and overall survival rates. Response was evaluated using positron emission tomography/computed tomography or computed tomography and detailed physical examination.

RESULTS

The median follow-up for all patients was 14 months (2-39 months). The median dose of prior radiation was 68.4 Gy (32-170 Gy). Patients were divided into 4 SBRT dose groups: I (15-28 Gy/n = 29), II (30-36 Gy/n = 22), III (40 Gy/n = 18), and IV (44-50 Gy/n = 27). The median gross tumor volume (GTV) was 24.3(3) cm (2.5-162 cm). For GTV ≤25 cm(3) (n = 50), complete response rates were 27.8%/30%/45.5%/45.5%, and for GTV >25 cm(3) (n = 46), complete response rates were 20%/25%/42.8%/50% for SBRT groups I-IV, respectively. The 1-/2-/3-year LRC rates for doses 40 to 50 Gy were 69.4%/57.8%/41.1%, respectively, whereas for 15 to 36 Gy, they were 51.9%/31.7%/15.9%, respectively (P = 0.02). The overall 1- and 2-year overall survival rates were 58.9% and 28.4%, respectively. Treatment was well tolerated with no grade 4/5 toxicities.

CONCLUSIONS

Dose escalation up to 50 Gy in 5 fractions is feasible with SBRT for recurrent head and neck squamous cell carcinoma. Higher SBRT doses were associated with significantly higher LRC rates. Large tumor volume required higher SBRT doses to achieve optimal response rates compared with smaller tumor volume.

Fractionated stereotactic body radiation therapy in the treatment of previously-irradiated recurrent head and neck carcinoma: updated report of the University of Pittsburgh experience

OBJECTIVES

The aim of this study was to assess the safety and outcome of stereotactic body radiotherapy (SBRT) in patients with recurrent previously irradiated squamous cell carcinoma of the head and neck (rSCCHN).

METHODS

We reviewed our experience with 85 patients who received SBRT for rSCCHN between January 2003 and May 2008. The mean dose of SBRT was 35 Gy (range: 15-44 Gy). The following end points were evaluated: tumor response, time-to-progression, acute and late toxicities, local control (LC) rates and impact of tumor dose and tumor size on LC, and overall survival.

RESULTS

The median follow-up of all patients was 6 months (range: 1.3-39 months). For those patients who were alive at last follow-up (40%) the median follow-up was 17.6 months. The mean total dose of prior radiation to the primary site was 74 Gy (range: 32-170 Gy). Those patients who received SBRT <35 Gy had significantly lower LC than those with > or =35 Gy at 6 months the median follow-up time (P = 0.014). Tumor responses were 34% complete response, 34% partial response, 20% stable disease, and 12% progressive disease. Among those with an initial tumor response followed by progression (58 patients), there was a median interval of 5.5 months for time-to-progression. The 1-year and 2-year LC and overall survival rates for all patients were 51.2% and 30.7%, and 48.5% and 16.1%, respectively. Overall, the median survival for all patients was 11.5 months (range: 3-51). Treatment was well-tolerated with no grade 4 or 5 treatment-related toxicities.

CONCLUSIONS

SBRT is feasible and safe with minimal toxicities for treatment of rSCCHN patients with prior radiation therapy deemed to be poor candidates for re-irradiation by conventional means.

Impact of diabetes mellitus on treatment outcomes in patients with nasopharyngeal cancer

BACKGROUND AND PURPOSE

To determine the influence of diabetes mellitus on stages and long-term outcomes among patients with nasopharyngeal cancer.

MATERIAL AND METHODS

The study summarized 37 patients who were diagnosed as having diabetes mellitus and nasopharyngeal cancer and treated by radiotherapy between January 1999 and December 1999. With a median follow-up of 34.6 mo, we analyzed differences in RFS, MFS, DFS, and OS between the diabetes and the non-diabetes group.

RESULTS

37 patients were involved in our study. According to the Chinese Fuzhou staging system for NPC, which was modified in 1992, 2 patients belong to stage I, 9 stage II, 17 stage III, and 6 stage IV. The 4-yr RFS of diabetes group and non-diabetes group was 52.1% vs 68.2%, the 4-yr MFS was 73.0% vs 72.0%, the 4-yr DFS was 35.1% vs 65.1%, and the OS was 67.6% vs 75.7%. The Wilcoxon (Gehan) test showed there was no significant difference between the two groups of RFS, MFS, and OS, while the diabetes group had a worse DFS than non-diabetes group (Wilcoxon p = 0.0047).

CONCLUSIONS

Patients with diabetes had a worse DFS than non-diabetes, but statistic tests did not show significant differences in RFS, MFS, and OS; further studies should be continue to find out the results in the future.

Emerging applications of stereotactic radiotherapy in head and neck cancer

Advances in the management of locally advanced head and neck cancer (HNC) have been focused on treatment intensification, including concomitant chemoradiotherapy, biological agents, and combining surgery with chemoradiotherapy. Despite these improvements, locoregional recurrence still constitutes the main pattern of treatment failure. As improvements in radiotherapy delivery and image-guided therapy have come to fruition, the principles of stereotactic radiosurgery are now being applied to extracranial sites, leading to stereotactic body radiotherapy. This article focuses on the emerging evidence for the use of stereotactic body radiotherapy for treatment of HNC as a boost after conventional external-beam radiotherapy, and also as reirradiation in recurrent or second primary HNC.

Outcome of Fractionated Stereotactic Radiotherapy for 90 Patients With Locally Persistent and Recurrent Nasopharyngeal Carcinoma

PURPOSE

Local recurrence remains one of the major causes of failure in nasopharyngeal carcinoma (NPC). Stereotactic radiosurgery and fractionated stereotactic radiation therapy (FSRT) have recently evolved as a salvage option of NPC. This study was conducted to review the treatment outcome after FSRT for NPC.

METHODS AND MATERIALS

Between September 1999 and December 2005, 90 patients with persistent (Group 1: n = 34, relapse within 6 months of RT) or recurrent (Group 2: n = 56, relapse beyond 6 months) NPC received FSRT using multiple noncoplanar arcs of 8-MV photon to the target. Median FSRT dose was 18 Gy in three fractions (Group 1) or 48 Gy in six fractions (Group 2). Median follow-up was 20.3 months.

RESULTS

Complete response rate after FSRT was 66% for Group 1 and 63% for Group 2. One-, 2-, and 3-year disease-specific survival (DSS) and progression-free survival (PFS) rates for all patients were 82.6%, 74.8%, 57.5%, and 72.9%, 60.4%, 54.5%, respectively. Three-year local failure-free survival, DSS, and PFS rates were 89.4%, 80.7%, and 72.3% for Group 1, and 75.1%, 45.9%, and 42.9% for Group 2, respectively. Multivariate analysis showed that recurrent disease and large tumor volume were independent factors that predicted poorer DSS and PFS. Seventeen patients developed late complications, including 2 with fatal hemorrhage.

CONCLUSIONS

Our results indicate that FSRT is effective for patients with persistent and recurrent NPC. Compared with reported results of radiosurgery, FSRT provides satisfactory tumor control and survival with a lower risk of complications and it may be a better treatment for local failures of NPC.

Minimally Invasive Endoscopic Nasopharyngectomy in the Treatment of Recurrent T1-2a Nasopharyngeal Carcinoma

OBJECTIVE

To study the efficacy of endoscopic nasopharyngectomy in salvaging recurrent T1 to 2a nasopharyngeal carcinoma (NPC).

STUDY DESIGN

An investigation of the outcome of endoscopic nasopharyngectomy.

METHODS

Six nasopharyngectomies for patients presenting with locally recurrent T1 to 2a NPC were performed exclusively by way of endoscopic resection by a single surgeon (m.-k.c.) during the period 2001 to 2005. All patients were operated on with curative intent without postoperative radiotherapy.

RESULTS

All six operations were successfully performed endoscopically, and no conversions to conventional open resection were necessary. Of the patients who underwent endoscopic excision, three of them had rT1 disease, and the others had rT2a disease. No surgical specimens had microscopic invasion of the resection margins. No complications associated with the operation occurred. The patients were followed up for 16 to 59 (average, 29) months. One local recurrence was noted in this series to date, and the patient was treated with intensity-modulated radiotherapy and chemotherapy.

CONCLUSIONS

Exclusively endoscopic nasopharyngectomy is a feasible method for treatment of locally recurrent T1- to 2a-staged NPC.

Salvage re-irradiation for recurrent head and neck cancer

PURPOSE

To present a retrospective review of treatment outcomes for recurrent head and neck (HN) cancer patients treated with re-irradiation (re-RT) at a single medical center.

METHODS AND MATERIALS

From July 1996-September 2005, 105 patients with recurrent HN cancer underwent re-RT at our institution. Sites included were: the neck (n = 21), nasopharynx (n = 21), paranasal sinus (n = 18), oropharynx (n = 16), oral cavity (n = 9), larynx (n = 10), parotid (n = 6), and hypopharynx (n = 4). The median prior RT dose was 62 Gy. Seventy-five patients received chemotherapy with their re-RT (platinum-based in the majority of cases). The median re-RT dose was 59.4 Gy. In 74 (70%), re-RT utilized intensity-modulated radiation therapy (IMRT).

RESULTS

With a median follow-up of 35 months, 18 patients were alive with no evidence of disease. The 2-year loco-regional progression-free survival (LRPFS) and overall survival rates were 42% and 37%, respectively. Patients who underwent IMRT, compared to those who did not, had a better 2-year LRPF (52% vs. 20%, p < 0.001). On multivariate analysis, non-nasopharynx and non-IMRT were associated with an increased risk of loco-regional (LR) failure. Patients with LR progression-free disease had better 2-year overall survival vs. those with LR failure (56% vs. 21%, p < 0.001). Acute and late Grade 3-4 toxicities were reported in 23% and 15% of patients. Severe Grade 3-4 late complications were observed in 12 patients, with a median time to development of 6 months after re-RT.

CONCLUSIONS

Based on our data, achieving LR control is crucial for improved overall survival in this patient population. The use of IMRT predicted better LR tumor control. Future aggressive efforts in maximizing tumor control in the recurrent setting, including dose escalation with IMRT and improved chemotherapy, are warranted.

Stereotactic radiosurgery as a salvage treatment for recurrent epipharyngeal carcinoma

Fourteen patients with recurrent epipharyngeal carcinoma (EPC) were treated by gamma knife stereotactic radiosurgery. The tumor volume ranged from 0.3 to 80 ml (median 18.9 ml). Treatment was done with a tumor margin dose of 10-27 Gy (median 15 Gy). The median follow-up period was 15 months (range 2-47 months). Ten patients were alive and 4 were dead at the end of the follow-up period. In 6 patients (43%), the tumor disappeared or decreased in size until the end of the follow-up period. In 2 (14%), the tumor remained unchanged in size. In 6 (43%), the tumor showed regression initially but was enlarged later. A second radiosurgery was performed in 4 of those 6 cases and the tumor decreased in size again in 3 of them. Thus, the overall control rate of local tumor was 79% (11/14). In selected patients with recurrent EPC, stereotactic radiosurgery can be considered as a salvage treatment producing local control.

Dose Escalation of Three-dimensional Conformal Radiotherapy for Locally Recurrent Nasopharyngeal Carcinoma: A Prospective Randomised Study

AIMS

To investigate prospectively the feasibility and efficacy of dose escalation using three-dimensional conformal radiotherapy (3D-CRT) boost technique for locally recurrent nasopharyngeal carcinoma (NPC) in a randomised study.

MATERIALS AND METHODS

Thirty-six patients with locally recurrent NPC (>6 months interval from previous radical radiotherapy, no cervical lymph-node involvement and no distant metastasis) were enrolled. Treatment included conventional external-beam radiotherapy to 54 Gy, followed by a 3D-CRT boost to the gross tumour region. Patients were randomised to three boost dose levels: 16 Gy, 20 Gy and 24 Gy for groups I, II and III, respectively, with 12 patients in each group. All boost doses were delivered in 4-Gy fractions and 3 fractions per week. Median follow-up was 27 months (range 14-44 months).

RESULTS

Three-year, local-recurrence-free survival rate was significantly higher (72%) for the high-dose group III than for groups I and II (37% and 28%, respectively, P = 0.047). No significant difference was found in the 3-year overall survival rate among the three groups (72%, 59% and 82% for groups I, II and III, respectively). Three-year distant metastases rates were 17%, 0% and 18%, respectively. Skull-base invasion (P = 0.017) and pathology (P = 0.0006) correlated with overall survival. Treatment was well tolerated and no significant difference was observed among the three groups in acute and late toxicities (grade III toxicity is minimal: 17%, 17%, 0% of oral mucositis and 25%, 17%, 17% of nasopharyngeal mucositis in groups I, II, III, respectively, and 8% leukocytopenia only in group II; no grade IV toxicity occurred in any of the groups except for a fatal bleeding in group III).

CONCLUSIONS

Re-irradiation with high-dose 3D-CRT boost technique results in high local control rate and acceptable toxicity in patients with recurrent NPC. Dose escalation to the boost volume to 78 Gy (54 Gy + 24 Gy boost) results in improved recurrence-free survival compared with lower doses.

Radiotherapy for nasopharyngeal carcinoma--transition from two-dimensional to three-dimensional methods

This review describes the clinical background that underlies the transition from two-dimensional to three-dimensional (3D) planning techniques in the treatment of nasopharyngeal cancer (NPC). A systematic search of the Medline was performed using 'nasopharyngeal carcinoma', 'radiotherapy', '3-dimensional conformal radiotherapy', 'stereotactic radiosurgery/radiotherapy' and 'intensity-modulated radiotherapy' as keywords. Citing evidence from the published literature and their own institutional experience, the authors critically examined the positive impact of 3D methods--with emphasis on intensity-modulated radiotherapy (IMRT)--on target coverage and geometric accuracy, sparing of normal organs, and dosimetric homogeneity. Potential problems related to the widespread practice of IMRT such as quality assurance, utilization of medical resources and the risk of developing radiation-induced secondary cancers were highlighted. Application of IMRT within the context of altered fractionation, dose escalation and concurrent chemotherapy were discussed. The article concluded with a suggested treatment approach and research direction for different stages of NPC.

Three-dimensional conformal radiotherapy versus intracavitary brachytherapy for salvage treatment of locally persistent nasopharyngeal carcinoma

PURPOSE

To compare the outcomes of three-dimensional conformal radiotherapy (3D-CRT) and intracavitary brachytherapy (ICBT) as salvage treatment for locally persistent nasopharyngeal carcinoma.

METHODS AND MATERIALS

Between March 1994 and November 2001, a total of 117 patients with locally persistent nasopharyngeal carcinoma received salvage treatment for 2-8 weeks (median, 4 weeks) after a full course of conventional external beam RT. Of the 117 patients, 54 were salvaged with 3D-CRT (3D group) and 63 with ICBT (BT group). No statistically significant differences were found in the patient characteristics between the two groups (p >0.05). In the 3D group, the planning target volume for 3D-CRT was defined as the persistent disease plus a 5-mm margin; three to seven static conformal coplanar or noncoplanar portals were delivered for each fraction. The median salvage dose was 24 Gy (range, 18-38 Gy), with fraction size of 2.0 Gy/d. In the BT group, a median salvage dose of 20 Gy (range, 15-30 Gy) was delivered with a (192)Ir source, at 5 Gy/fraction, twice weekly. The brachytherapy dose was prescribed at a distance of 1 cm from the center of the surface as defined by the sources, irrespective of the extent of persistent disease. The actuarial rates of survival were estimated using the Kaplan-Meier method. Potential differences in the actuarial outcomes between groups were evaluated using the Mantel log-rank test. Multivariate analyses were performed with the Cox regression proportional hazards model.

RESULTS

The 5-year actuarial rates of overall survival, disease-specific survival, and local failure-free survival for the 3D group and BT group were 64.50% vs. 55.78% (p = 0.33), 70.03% vs. 59.56% (p = 0.11), and 88.93% vs. 76.28% (p = 0.07), respectively. Subgroup analysis showed that the 5-year actuarial local failure-free survival rate of patients with initially diagnosed T3-T4 disease for the 3D group and BT group was 84.01% vs. 60.50% (p = 0.03). The incidence of Grade 3-4 late complications was comparable between the two groups. Multivariate analyses performed in the whole group showed that T stage at initial diagnosis and the salvage technique (3D-CRT or ICBT) were the statistically significant, independent prognostic factors for local failure-free survival (p = 0.00 and p = 0.02, respectively).

CONCLUSION

3D-CRT seemed to provide better local control than ICBT as a salvage treatment for locally persistent nasopharyngeal carcinoma, especially in patients with initially diagnosed T3-T4 disease. CT/MRI evaluation of the extent of persistent disease is recommended for technique selection of salvage RT. Patients should be cautioned about the potentially increased complications. The optional time for salvage treatment remains controversial.

Initial experience using intensity-modulated radiotherapy for recurrent nasopharyngeal carcinoma

PURPOSE

To report our initial experience on the feasibility, toxicity, and tumor control using intensity-modulated radiotherapy (IMRT) for retreatment of recurrent nasopharyngeal carcinoma (NPC).

METHODS AND MATERIALS

A total of 49 patients with locoregional recurrent carcinoma in the nasopharynx were treated with IMRT between January 2001 and February 2002 at the Sun Yat-Sen University Cancer Center, Guangzhou, China. The average time to the nasopharyngeal recurrence was 30.2 months after initial conventional RT. The median isocenter dose to the nasopharynx was 70 Gy (range 60.9-78.0) for the initial conventional RT. All patients were restaged at the time of recurrence according to the 1992 Fuzhou, China staging system on NPC. The number of patients with Stage I, II, III and IV disease was 4, 9, 10, and 26, respectively. T1, T2, T3, and T4 disease was found in 4, 9, 11, and 25 patients, respectively. N0, N1, N2, and N3 disease was found in 46, 2, 0, and 1 patient, respectively. Invasion of the nasal cavity, maxillary sinus, ethmoid sinus, sphenoid sinus, and cavernous sinus and erosion of the base of the skull was found in 8, 1, 3, 8, 15, and 20 patients, respectively. The gross tumor volume (GTV) was contoured according to the International Commission on Radiation Units and Measurements (ICRU) Report 62 guidelines. The critical structures were contoured, and the doses to critical structures were constrained according to ICRU 50 guidelines. The GTV in the nasopharynx and positive lymph nodes in the neck received a prescription dose of 68-70 Gy and 60 Gy, respectively. All patients received full-course IMRT. Three patients who had positive lymph nodes were treated with five to six courses of chemotherapy (cisplatin + 5-fluorouracil) after IMRT.

RESULTS

The treatment plans showed that the percentage of GTV receiving 95% of the prescribed dose (V(95-GTV)) was 98.5%, and the dose encompassing 95% of GTV (D(95-GTV)) was 68.1 Gy in the nasopharynx. The mean dose to the GTV was 71.4 Gy. The average doses of the surrounding critical structures were much lower than the tolerable thresholds. At a median follow-up of 9 months (range 3-13), the locoregional control rate was 100%. Three cases (6.1%) of locoregional residual disease were seen at the completion of IMRT, but had achieved a complete response at follow-up. Three patients developed metastases at a distant site: two in the bone and one in the liver and lung at 13 months follow-up. Acute toxicity (skin, mucosa, and xerostomia) was acceptable according to the Radiation Therapy Oncology Group criteria. Tumor necrosis was seen toward the end of IMRT in 14 patients (28.6%).

CONCLUSION

The improvement in tumor target coverage and significant sparing of adjacent critical structures allow the feasibility of IMRT as a retreatment option for recurrent NPC after initial conventional RT. This is the first large series using IMRT to reirradiate local recurrent NPC after initial RT failed. The treatment-related toxicity profile was acceptable. The initial tumor response/local control was also very encouraging. In contrast to primary NPC, recurrent NPC reirradiated with high-dose IMRT led to the shedding of tumor necrotic tissue toward the end of RT. More patients and longer term follow-up are warranted to evaluate late toxicity and treatment outcome.

Effectiveness of brachytherapy and fractionated stereotactic radiotherapy boost for persistent nasopharyngeal carcinoma

BACKGROUND

Nasopharyngeal carcinoma (NPC) with local persistence after primary radiotherapy carries a high risk of treatment failure. We compared the effectiveness of brachytherapy and a fractionated stereotactic radiotherapy (SRT) boost in improving tumor control.

METHODS

We retrospectively reviewed the records of 755 patients with NPC treated from 1994 to 2001. Fifty-two patients (7%) had persistent local disease, but seven of them were unsuitable for radiotherapy boost. Overall, 24 patients received brachytherapy boost at a median dose of 20 Gy, and 21 patients received an SRT boost at a median dose of 15 Gy.

RESULTS

Despite the radiotherapy boost, the overall 3-year local failure-free control rate was still significantly lower for patients with persistent disease than for the rest (71% vs 86%, p < .01). Only the SRT subgroup achieved a local failure-free control rate close to that of the complete responders (82% vs 86%, p = .71).

CONCLUSIONS

SRT boost is more effective in reverting the poor prognostic influence of local persistent disease.

Improved local control with stereotactic radiosurgical boost in patients with nasopharyngeal carcinoma

PURPOSE

Treatment of nasopharyngeal carcinoma using conventional external beam radiotherapy (EBRT) alone is associated with a significant risk of local recurrence. Stereotactic radiosurgery (STR) was used to boost the tumor site after EBRT to improve local control.

METHODS AND MATERIALS

Forty-five nasopharyngeal carcinoma patients received a STR boost after EBRT at Stanford University. Seven had T1, 16 had T2, 4 had T3, and 18 had T4 tumors (1997 American Joint Commission on Cancer staging). Ten had Stage II, 8 had Stage III, and 27 had Stage IV neoplasms. Most patients received 66 Gy of EBRT delivered at 2 Gy/fraction. Thirty-six received concurrent cisplatin-based chemotherapy. STR was delivered to the primary site 4-6 weeks after EBRT in one fraction of 7-15 Gy.

RESULTS

At a medium follow-up of 31 months, no local failures had occurred. The 3-year local control rate was 100%, the freedom from distant metastasis rate was 69%, the progression-free survival rate was 71%, and the overall survival rate was 75%. Univariate and multivariate analyses revealed N stage (favoring N0-N1, p = 0.02, hazard ratio HR 4.2) and World Health Organization histologic type (favoring type III, p = 0.002, HR 13) as significant factors for freedom from distant metastasis. World Health Organization histologic type (p = 0.004, HR 10.5) and age (p = 0.01, HR 1.07/y) were significant factors for survival. Late toxicity included transient cranial nerve weakness in 4, radiation-related retinopathy in 1, and asymptomatic temporal lobe necrosis in 3 patients who originally had intracranial tumor extension.

CONCLUSION

STR boost after EBRT provided excellent local control in nasopharyngeal carcinoma patients. The incidence of late toxicity was acceptable. More effective systemic treatment is needed to achieve improved survival.

Treatment outcome for synchronous locoregional failures of nasopharyngeal carcinoma

BACKGROUND

To review the outcome and evaluate the prognostic factors in the treatment of synchronous locoregional failures of nasopharyngeal carcinoma (NPC).

METHODS

We reviewed the records of 43 patients with synchronous locoregional failures of NPC who received salvage treatment or chemotherapy between November 1986 and January 2001. The recurrent disease was stage II in 61%, stage III in 30%, and stage IV in 9%. The local disease was rT1-2 in 67% and rT3-4 in 33%, and the regional disease was rN1 in 91% and rN2 in 9%. Persistent disease, defined as failures within 4 months of completion of primary radiotherapy, occurred in 53.5% and recurrent disease in 46.5%. Seventeen patients received surgery for regional and/or local failures with or without combined radiotherapy (ST group), 14 patients received reirradiation to both local and regional disease (RT group), and 12 patients received palliative chemotherapy only (CT group). The median follow-up was 18 months (range, 4-153) and for the surviving patients it was 29 months (range, 6-153).

RESULTS

The 3-year relapse-free survival (RFS) rate and disease-specific survival (DSS) rate after salvage treatment or chemotherapy were 17% and 38%, respectively. The 3-year RFS rates in stage II, III, and IV disease were 25%, 8%, and 0%, respectively. The corresponding 3-year DSS rates were 43%, 28%, and 38%. The 3-year RFS rates in the ST, RT, and CT group were 39%, 7%, and 0%, respectively. The corresponding 3-year DSS rates were 55%, 25%, and 25%. Patients whose local disease was treated by surgical resection had a 3-year local control rate of 71% compared with 38% by reirradiation using brachytherapy or external radiotherapy. For regional disease, the 3-year nodal control rate after radical neck dissection was 65% compared with 24% by reirradiation. Further locoregional failure represents the major failure pattern, and the proportion of patients who had further local, regional, and both locoregional failures were 16%, 9%, and 53%, respectively. Distant metastasis occurred in 30% of patients, and only 5% had isolated distant metastasis in the absence of locoregional failures. On multivariate analysis, treatment by reirradiation or chemotherapy alone and rN2 disease were independent factors that predicted poor survival, whereas treatment by reirradiation or chemotherapy alone was the only independent factor that predicted further relapse or failure.

CONCLUSIONS

Proper selection of patients for aggressive salvage treatment and individualization of treatment are important in managing patients with synchronous locoregional failures of NPC. A significant proportion of patients with early stage locoregional failures can still achieve long-term disease control and survival after aggressive salvage treatment using surgery with or without combined radiotherapy. In patients with more advanced disease, treatment by reirradiation alone or palliative chemotherapy is largely ineffective and is associated with a poor outcome.

Linear accelerator-based stereotactic radiosurgery for limited, locally persistent, and recurrent nasopharyngeal carcinoma: efficacy and complications

PURPOSE

To evaluate the efficacy and complication of linear accelerator-based stereotactic radiosurgery (SRS) when used as salvage treatment for early-stage persistent and recurrent nasopharyngeal carcinoma (NPC) after primary radiotherapy (RT).

MATERIALS AND METHODS

Between March 1998 and June 2001, 18 patients (15 men and 3 women; median age 46 years, range 32-84) with locally persistent or recurrent NPC confined to the nasopharynx (rT1) or with limited extension to the nasal fossa or parapharyngeal space (rT2) were treated by SRS. Thirteen patients had rT1 disease and 5 had rT2 disease. Most patients had disease not amenable to surgery or brachytherapy. All patients had undergone previous radical RT. Persistent disease was defined as tumor relapse within 4 months of completion of primary RT, and recurrence as tumor relapse beyond 4 months. Seven patients were treated for persistent disease, eight for a first recurrence, and three for a second recurrence. SRS was performed using multiple noncoplanar arcs of photons delivered to the target volume, which was defined by axial CT at a 3 mm thickness, supplemented by MRI in selected patients (67%). The median target volume was 5.3 cm(3) (range 2.2-16.9). The median SRS dose was 12.5 Gy (range 11-14) delivered to the 80% isodose line. All patients underwent serial nasopharyngoscopy and imaging after SRS. The median follow-up was 26 months (range 11-48).

RESULTS

After SRS, 16 (89%) of 18 patients had complete regression of tumor as assessed by nasopharyngoscopy and biopsy. Four patients with an initial complete response to SRS subsequently developed local relapse again, with one recurrence developing outside the target volume 8 months after SRS and three within the target volume at 6-26 months after SRS. Two patients with local disease controlled by SRS developed relapse in other sites (neck node and liver metastases). The actuarial 2-year local control rate after SRS was 72%. Patients treated for persistent disease had a better local control rate (100%; 7 of 7) than those treated for recurrent disease (46%; 5 of 11). Patients with rT1 disease also had a better outcome after SRS compared with those with rT2 disease, with a control rate of 77% (10 of 13) for rT1 disease and 40% (2 of 5) for rT2 disease. Treatments were well tolerated, with no acute side effects. One patient had radiologic evidence of temporal lobe necrosis, although the right temporal lobe had already received a high dose during prior RT. That patient also developed additional local recurrence and liver metastases and died. The actuarial 2-year survival rate was 86%.

CONCLUSIONS

Our preliminary results indicate that SRS is an effective treatment modality for persistent and recurrent early-stage NPC, with early control rates comparable to other salvage treatments such as brachytherapy and nasopharyngectomy. A modest SRS dose at 12.5 Gy also appears to be effective and is associated with minimal morbidities. More clinical experience and longer follow-up are needed to validate our results and to address fully the role of SRS in salvaging local failures of NPC.

Reirradiation of nasopharyngeal carcinoma with intracavitary mold brachytherapy: an effective means of local salvage

PURPOSE

To assess the role of intracavitary mold brachytherapy in salvaging local failure of nasopharyngeal carcinoma (NPC).

METHODS AND MATERIALS

The outcomes of 118 consecutive NPC patients with local failure treated with mold brachytherapy between 1989 and 1996 were retrospectively reviewed. Eleven patients received additional external radiotherapy.

RESULTS

All molds were tailor-made, and the whole procedure was performed under local anesthesia. Pharyngeal recess dissection was routinely performed to allow direct contact of the radioactive source with the pharyngeal recess, a common site of local failure. Initially, the molds were preloaded with 192Ir wires, but since 1992, the sources have been manually afterloaded; the mold has also been redesigned for better conformity, ease of insertion, and radiation safety. Using brachytherapy alone, 50-55 Gy was given for recurrence in 4-7 days; for persistence, 40 Gy was administered. The overall complete remission rate was 97%. The rates of 5-year local control, relapse-free survival, disease-specific survival, overall survival, and major complication were 85%, 68.3%, 74.8%, 61.3%, and 46.9%, respectively. Major complications included nasopharyngeal necrosis with headache, necrosis of cervical vertebrae with atlantoaxial instability, temporal lobe necrosis, and palsy of the cranial nerves. The afterloaded mold was as effective as the preloaded version, but with fewer complications.

CONCLUSIONS

Intracavitary mold brachytherapy was effective in salvaging NPC with early-stage local persistence or first recurrence.

Underdosage of the upper-airway mucosa for small fields as used in intensity-modulated radiation therapy: a comparison between radiochromic film measurements, Monte Carlo simulations, and collapsed cone convolution calculations

Head-and-neck tumors are often situated at an air-tissue interface what may result in an underdosage of part of the tumor in radiotherapy treatments using megavoltage photons, especially for small fields. In addition to effects of transient electronic disequilibrium, for these small fields, an increased lateral electron range in air will result in an important extra reduction of the central axis dose beyond the cavity. Therefore dose calculation algorithms need to model electron transport accurately. We simulated the trachea by a 2 cm diameter cylindrical air cavity with the rim situated 2 cm beneath the phantom surface. A 6 MV photon beam from an Elekta SLiplus linear accelerator, equipped with the standard multileaf collimator (MLC), was assessed. A 10 x 2 cm2 and a 10 x 1 cm2 field, both widthwise collimated by the MLC, were applied with their long side parallel to the cylinder axis. Central axis dose rebuild-up was studied. Radiochromic film measurements were performed in an in-house manufactured polystyrene phantom with the films oriented either along or perpendicular to the beam axis. Monte Carlo simulations were performed with BEAM and EGSnrc. Calculations were also performed using the pencil beam (PB) algorithm and the collapsed cone convolution (CCC) algorithm of Helax-TMS (MDS Nordion, Kanata, Cahada) version 6.0.2 and using the CCC algorithm of Pinnacle (ADAC Laboratories, Milpitas, CA, USA) version 4.2. A very good agreement between the film measurements and the Monte Carlo simulations was found. The CCC algorithms were not able to predict the interface dose accurately when lateral electronic disequilibrium occurs, but were shown to be a considerable improvement compared to the PB algorithm. The CCC algorithms overestimate the dose in the rebuild-up region. The interface dose was overestimated by a maximum of 31% or 54%, depending on the implementation of the CCC algorithm. At a depth of 1 mm, the maximum dose overestimation was 14% or 24%.