Radiation treatment for cervical esophagus: patterns of practice study in Canada, 1996

Outcomes and prognostic factors for patients with cervical esophageal cancer undergoing definitive radiotherapy or chemoradiotherapy

Cervical esophageal cancer (CEC) is uncommon, accounting for less than 5% of all esophageal cancers. The management of CEC is controversial. This study investigated treatment outcomes and prognostic factors of survival in CEC patients undergoing definitive radiotherapy or concurrent chemoradiotherapy (CCRT). Ninety-one CEC patients were treated by intensity-modulated radiation therapy (IMRT) and three-dimensional conformal radiation therapy (3DCRT) between July 2007 and September 2017. The mean prescription dose was 64 Gy (range 54-70 Gy) delivered as 1.8-2.2 Gy per fraction per day, 5 days a week. Out of 91 patients, 34 received concurrent cisplatin-based chemotherapy (CT) including 18 patients who also received neoadjuvant CT. Overall survival (OS), locoregional failure-free survival (LRFFS), and progression-free survival (PFS) were estimated by the Kaplan-Meier method. Prognostic factors of survival were determined in univariate (log-rank test) and multivariate (Cox proportional hazard model) analysis. Treatment-related toxicity was also assessed. Median follow-up time for all patients was 19 months. Two-year OS, LRFFS and PFS of all patients were 58.2%, 52.5% and 48.1%, respectively. Clinical stage was an independent prognostic factor for OS (HR = 2.35, 95% CI: 1.03-5.37, p = 0.042), LRFFS (HR = 3.84, 95% CI: 1.38-10.69, p = 0.011), and PFS (HR = 2.68, 95% CI: 1.11-6.45, p = 0.028). Hoarseness was an independent prognostic factor for OS (HR = 2.10, 95% CI: 1.05-4.19, p = 0.036). CCRT was independently associated with better LRFFS (HR = 0.33, 95% CI: 0.14-0.79, p = 0.012). 3DCRT and IMRT with concurrent CT is well-tolerated and may improve local tumor control in CEC patients. Advanced clinical stage and hoarseness are adverse prognostic factors for OS, LRFFS, and PFS in CEC.

Three-dimensional conformal radiation therapy for esophageal squamous cell carcinoma: is elective nodal irradiation necessary?

PURPOSE

To evaluate the local control, survival, and toxicity associated with three-dimensional conformal radiotherapy (3D-CRT) for squamous cell carcinoma (SCC) of the esophagus, to determine the appropriate target volumes, and to determine whether elective nodal irradiation is necessary in these patients.

METHODS AND MATERIALS

A prospective study of 3D-CRT was undertaken in patients with esophageal SCC without distant metastases. Patients received 68.4 Gy in 41 fractions over 44 days using late-course accelerated hyperfractionated 3D-CRT. Only the primary tumor and positive lymph nodes were irradiated. Isolated out-of-field regional nodal recurrence was defined as a recurrence in an initially uninvolved regional lymph node.

RESULTS

All 53 patients who made up the study population tolerated the irradiation well. No acute or late Grade 4 or 5 toxicity was observed. The median survival time was 30 months (95% confidence interval, 17.7-41.8). The overall survival rate at 1, 2, and 3 years was 77%, 56%, and 41%, respectively. The local control rate at 1, 2, and 3 years was 83%, 74%, and 62%, respectively. Thirty-nine of the 53 patients (74%) showed treatment failure. Seventeen of the 39 (44%) developed an in-field recurrence, 18 (46%) distant metastasis with or without regional failure, and 3 (8%) an isolated out-of-field nodal recurrence only. One patient died of disease in an unknown location.

CONCLUSIONS

In patients treated with 3D-CRT for esophageal SCC, the omission of elective nodal irradiation was not associated with a significant amount of failure in lymph node regions not included in the planning target volume. Local failure and distant metastases remained the predominant problems.

Dosimetric comparison of IMRT vs. 3D conformal radiotherapy in the treatment of cancer of the cervical esophagus

BACKGROUND AND PURPOSE

Radiotherapy planning for cervical esophageal cancer is challenging. We compared IMRT and 3D conformal radiotherapy (CRT) with respect to conformality of target coverage and normal tissue sparing.

MATERIALS AND METHODS

We selected five patients with cervical esophagus cancer, who represented the heterogeneity of clinical cases, treated to radical dose and planned with Pinnacle v6.2. Target doses for CRT plans were 50, 60, and 70Gy (single-phase IMRT 56, 63, and 70). We compared PTV coverage by the 95% isodose (PTV(95)), conformality ratio (CR), conformation number (CN), and maximum or mean doses (D(max), D(mean)) to normal structures.

RESULTS

Median PTV(95) for IMRT plans for PTV70, PTV63, and PTV56 were 97%, 99%, and 98% (CRT 91%, 98%, and 85%). IMRT plans demonstrated lower D(max) to the spinal cord and brainstem (42 and 36Gy) compared to CRT (46 and 39Gy). Median left parotid D(mean) was 35Gy (IMRT) vs. 53Gy (CRT). Median right parotid D(mean) was 35Gy (IMRT) vs. 36Gy (CRT). The median CR50/56Gy was 1.4 (CRT) vs. 1.2 (IMRT), CR70Gy 1.7 (CRT) vs. 1.1 (IMRT). CN50/56 and CN70 values were 0.80 and 0.85 (IMRT) vs. 0.56 and 0.5 (CRT).

CONCLUSIONS

IMRT provides superior target volume coverage and conformality, with decreased dose to normal structures.

Intensity-modulated radiation therapy with concurrent chemotherapy for locally advanced cervical and upper thoracic esophageal cancer

AIM: To evaluate the dosimetry, efficacy and toxicity of intensity-modulated radiation therapy (IMRT) and concurrent chemotherapy for patients with locally advanced cervical and upper thoracic esophageal cancer.

METHODS: A retrospective study was performed on 7 patients who were definitively treated with IMRT and concurrent chemotherapy. Patients who did not receive IMRT radiation and concurrent chemotherapy were not included in this analysis. IMRT plans were evaluated to assess the tumor coverage and normal tissue avoidance. Treatment response was evaluated and toxicities were assessed.

RESULTS: Five- to nine-beam IMRT were used to deliver a total dose of 59.4-66 Gy (median: 64.8 Gy) to the primary tumor with 6-MV photons. The minimum dose received by the planning tumor volume (PTV) of the gross tumor volume boost was 91.2%-98.2% of the prescription dose (standard deviation [SD]: 3.7%-5.7%). The minimum dose received by the PTV of the clinical tumor volume was 93.8%-104.8% (SD: 4.3%-11.1%) of the prescribed dose. With a median follow-up of 15 mo (range: 3-21 mo), all 6 evaluable patients achieved complete response. Of them, 2 developed local recurrences and 2 had distant metastases, 3 survived with no evidence of disease. After treatment, 2 patients developed esophageal stricture requiring frequent dilation and 1 patient developed tracheal-esophageal fistula.

CONCLUSION: Concurrent IMRT and chemotherapy resulted in an excellent early response in patients with locally advanced cervical and upper thoracic esophageal cancer. However, local and distant recurrence and toxicity remain to be a problem. Innovative approaches are needed to improve the outcome.

Radiation treatment of lung cancer—Patterns of Practice in Canada

BACKGROUND AND PURPOSE

To assess the patterns of practice among Canadian radiation oncologists who treat lung cancers.

PATIENTS AND METHODS

A questionnaire detailing different aspects of radiation treatment of lung cancer was mailed to all radiation oncologists treating lung cancer in Canada. Seventy-two percent (74/103) of radiation oncologists who treat lung cancer from all 34 Canadian cancer centres replied to the questionnaire.

RESULTS

(a) Radiotherapy regimens in Canadian cancer centres are in accordance with several major randomised studies. There is still some variation in treatment practice that may be due to unresolved controversies or limited resources. The most frequently used prescription dose was 40Gy/15f/3w (where f stands for fractions and w stands for weeks) for small cell lung cancer (SCLC) and 60Gy/30f/6w for non-small cell lung cancer (NSCLC). If there were no resource constraints, 30% (22/74) and 20% (15/74) would prefer to use a different dose-fractionation scheme for SCLC and NSCLC, respectively; 95% (70/74) would prefer to use 3D-conformal or intensity-modulated radiotherapy. (b) Among the various modern technologies assessed by respondents, CT (computed tomography) simulator, multi-leaf collimator, on-line electronic portal imaging and PET (positron-emission tomography) scanning were rated the highest in terms of potential patient benefit. Discrepancy between demand and availability of technology was greatest for PET scanning.

CONCLUSIONS

Canadian practice in the treatment of lung cancers shows some variations although it is consistent with the trends in the literature. The lack of some modern technologies and human resources is an ongoing concern, especially the lack of PET imaging equipment.

Comparison of conformal and intensity-modulated techniques for simultaneous integrated boost radiotherapy of upper esophageal carcinoma

AIM: To compare intensity-modulated radiotherapy (IMRT) with conformal radiotherapy (CRT) by investigating the dose profiles of primary tumors, electively treated regions, and the doses to organs at risk.

METHODS: CRT and IMRT plans were designed for five patients with upper esophageal carcinoma. For each patient, target volumes for primary lesions (67.2 Gy) and electively treated regions (50.4 Gy) were predefined. An experienced planner manually designed one CRT plan. Four IMRT plans were generated with the same dose-volume constraints, but with different beam arrangements. Indices including dose distributions, dose volume histograms (DVHs) and conformity index were compared.

RESULTS: The plans with three intensity-modulated beams were discarded because the doses to spinal cord were lager than the tolerable dose 45Gy, and the dose on areas near the skin was up to 50Gy. When the number of intensity beams increased to five, IMRT plans were better than CRT plans in terms of the dose conformity and homogeneity of targets and the dose to OARs. The dose distributions changed little when the beam number increased from five to seven and nine.

CONCLUSION: IMRT is superior to CRT for the treatment of upper esophageal carcinoma with simultaneous integrated boost (SIB). Five equispaced coplanar intensity-modulated beams can produce desirable dose distributions. The primary tumor can get higher equivalent dose by SIB technique. The SIB-IMRT technique shortens the total treatment time, and is an easier, more efficient, and perhaps a less error-prone way in delivering IMRT.