Follow up results of a prospective study to evaluate the impact of FDG-PET on CT-based radiotherapy treatment planning for oesophageal cancer

Background

This prospective study aims to determine the impact of PET/CT on radiotherapy planning and outcomes in patients with oesophageal cancer.

Methods

All patients underwent PET/CT scanning in the radiotherapy treatment position, and received treatment planned using the PET/CT dataset. GTV was defined separately on PET/CT (GTV-PET) and CT (GTV-CT) datasets. A corresponding PTV was generated for each patient. Volumetric and spatial analysis quantified the proportion of FDG-avid disease not included in CT-based volumes. Clinical data was collected to determine locoregional control and overall survival rates.

Results

13 (24.1%) of 57 accrued patients had metastatic disease detected on PET. Median follow up was 4 years. FDG-avid disease would have been excluded from GTV-CT in 29 of 38 patients (76%). In 5 patients, FDG-avid disease would have been completely excluded from the PTV-CT. GTV-CT underestimated the cranial and caudal extent of FDG-avid tumour in 14 (36%) and 10 (26%) patients. 4-Year overall survival and locoregional failure free survival were 37% and 65%.

Conclusions

PET/CT altered the delineation of tumour volumes when compared to CT alone, and should be considered standard for treatment planning. Although clinical outcomes were not improved with PET/CT planning, it did allow the use of smaller radiotherapy volumes.

A phase Ib/II translational study of sunitinib with neoadjuvant radiotherapy in soft-tissue sarcoma

Background:

Preoperative radiotherapy (RT) is commonly used to treat localised soft-tissue sarcomas (STS). Hypoxia is an important determinant of radioresistance. Whether antiangiogenic therapy can ‘normalise' tumour vasculature, thereby improving oxygenation, remains unknown.

Methods:

Two cohorts were prospectively enrolled. Cohort A evaluated the implications of hypoxia in STS, using the hypoxic tracer ¹⁸F-azomycin arabinoside (FAZA-PET). In cohort B, sunitinib was added to preoperative RT in a dose-finding phase 1b/2 design.

Results:

In cohort A, 13 out of 23 tumours were hypoxic (FAZA-PET), correlating with metabolic activity (r²=0.85; P<0.001). Two-year progression-free (PFS) and overall (OS) survival were 61% (95% CI: 0.44–0.84) and 87% (95% CI: 0.74–1.00), respectively. Hypoxia was associated with radioresistance (P=0.012), higher local recurrence (Hazard ratio (HR): 10.2; P=0.02), PFS (HR: 8.4; P=0.02), and OS (HR: 41.4; P<0.04). In Cohort B, seven patients received sunitinib at dose level (DL): 0 (50 mg per day for 2 weeks before RT; 25 mg per day during RT) and two patients received DL: −1 (37.5 mg per day for entire period). Dose-limiting toxicities were observed in 4 out of 7 patients at DL 0 and 2 out of 2 patients at DL −1, resulting in premature study closure. Although there was no difference in PFS or OS, patients receiving sunitinib had higher local failure (HR: 8.1; P=0.004).

Conclusion:

In STS, hypoxia is associated with adverse outcomes. The combination of sunitinib with preoperative RT resulted in unacceptable toxicities, and higher local relapse rates.

Once-daily reirradiation for rectal cancer in patients who have received previous pelvic radiotherapy

INTRODUCTION

The purpose of this study is to assess the efficacy and toxicity using once-daily reirradiation for patients with rectal cancer having received previous pelvic radiotherapy.

METHOD

Between June 1997 and June 2008, 56 patients were identified having received previous pelvic radiotherapy and received reirradiation for rectal cancer. Reirradiation intent was palliative in 43 patients, and preoperative/postoperative in 13 patients. Eighty per cent of patients received concurrent chemotherapy (n = 45).

RESULTS

The median dose-fractionation reirradiation schedule was 39.6 Gy in 22 fractions once daily (range 20-39.6 Gy), and the median cumulative radiation dose was 87.3 Gy. Seven patients experienced a grade 3 acute toxicity, with no grade 4 event. Fifty-one patients (91%) completed the treatment and five patients required a treatment break. The overall symptomatic response rate was 88% at three months post-reirradiation. There was one late effect of skin ulceration among patients reirradiated palliatively. Median overall survival was 39 months in patients undergoing radical surgery versus 15 months in patients reirradiated palliatively (P < 0.001).

CONCLUSION

Once-daily reirradiation to a total dose of ≤39.6 Gy is relatively safe in the treatment of patients with rectal cancer after previous pelvic radiotherapy. It is effective in symptom control and provides an additional option in management of local recurrence.

Chemoradiotherapy in the management of primary squamous-cell carcinoma of the rectum

AIM

To assess the efficacy of chemoradiotherapy in the management of primary squamous-cell carcinoma of the rectum.

METHOD

Nine patients with primary squamous-cell carcinoma of the rectum were treated with chemoradiotherapy from 1985 to 2007. All patients were female, with a mean age of 54 years (range 41-72 years). The mean distance of the tumour from the anal verge was 6 cm (range 4-10 cm). Seven patients were treated with curative intent (two postoperative, three preoperative, two chemoradiotherapy alone). Clinical stages for the curative group were T1N0M0 (1), T3N0M0 (3), T3N1M0 (1) and T4N0M0 (2). Chemoradiotherapy consisted of pelvic radiation 45-54 Gy in 1.8 Gy/fraction and concurrent 5-fluorouracil and mitomycin C. The mean follow-up duration for the curative group was 39 months (range 15-120 months).

RESULTS

All seven patients treated with curative intent achieved local control. A complete pathological response was seen in all patients after preoperative chemoradiotherapy. Two patients did not have surgery and remained free of disease. One patient with gross residual disease after surgery achieved local control. 18-Fluorodeoxyglucose (FDG) avidity was detected in all patients who had FDG-PET scans. Both primary and metastatic tumours demonstrated FDG-avidity.

CONCLUSION

Primary squamous-cell carcinoma of the rectum appears to be very sensitive to chemoradiotherapy. The high complete response rate suggests that chemoradiotherapy alone with salvage surgery for local failure should be further explored. FDG-PET scan may have a role to play in the management of this disease.

Surgical outcome of soft tissue sarcomas of the adductor compartment

PURPOSE

To review outcomes and complications of 25 consecutive patients with soft tissue sarcomas in the adductor compartment.

METHODS

Records of 11 men and 14 women aged 20 to 83 (mean, 56) years who underwent resection for soft tissue sarcomas in the adductor compartment were reviewed. Two of the patients had undergone inadequate resection of the tumour elsewhere. No patient had metastases. 20 and 2 patients underwent neo-adjuvant and postoperative radiotherapy, respectively. The interval between radiotherapy and surgery was at least 3 weeks. No neo-adjuvant chemotherapy was given. 24 patients underwent limb salvage surgery and one had external hemipelvectomy. 21 patients had direct wound closure; in 4 a microsurgical free flap was used.

RESULTS

The overall survival rate was 81% and 72% at 3 and 5 years, respectively, and remained unchanged until the end of follow-up. Four patients died from pulmonary metastases and one died from liver metastases. One patient had local recurrence, and 7 (26%) developed major complications. Five patients underwent revision surgery.

CONCLUSION

Good survival and local control rates can be achieved in patients with soft tissue sarcomas in the adductor compartment using limb salvage and radiotherapy.

Radiation therapy in the treatment of desmoid tumours reduces surgical indications

BACKGROUND

While several modalities have been proposed for the treatment of desmoid tumour/aggressive fibromatosis, high local recurrence rates have been reported. We present a retrospective study of including patients treated with radiation therapy, some of them in combination with surgical resection.

PATIENTS AND METHODS

Thirty-four consecutive patients were included (mean age 40+/-16 years, 9 male). Complete follow-up was available in 31 patients (51+/-36 months). Seventeen patients (50%) were treated with radiation therapy alone, 17 patients with radiation therapy and surgery. Radiation therapy (external beam) was applied in most cases to a total dose of 50.4 Gy in 28 fractions. The lesion was located in the upper extremity in 11 patients, in the lower extremity in 14 cases and on the trunk in 9 cases.

RESULTS

Overall recurrence/progression free survival was 88.5% at 5 years and 77.5% at 10 years. Recurrence free survival of the subset of patients undergoing combined treatment with radiation therapy and surgical resection was 83.6% at 5 years and 10 years. In patients who did not receive surgery but only radiation therapy, MRI showed a complete response in 20%, a partial response in 20%, and stable disease in 53% of cases. In this subset, two-third of patient had a metabolic response to radiotherapy (i.e. decrease uptake on the thallium-210 scan after radiotherapy compared to pre-therapy levels).

CONCLUSION

Low recurrence rates can be achieved with the use of radiation therapy alone in selected cases. Patients with a metabolic response (decrease) to radiotherapy may be treated with a non-surgical approach. Surgery might be considered in patients with a poor metabolic response to radiotherapy.

A prospective study to evaluate the impact of FDG-PET on CT-based radiotherapy treatment planning for oesophageal cancer

BACKGROUND AND PURPOSE

This prospective study sought to determine how the use of combined PET/CT for radiotherapy treatment planning of oesophageal cancer would alter the delineation of tumour volumes compared to CT alone if PET/CT is assumed to more accurately represent true disease extent.

PATIENTS AND METHODS

All patients underwent FDG-PET/CT scanning in the radiotherapy treatment position. For each patient, two separate gross tumour volumes (GTV) were defined, one based on CT images alone (GTV-CT) and another based on combined PET/CT data (GTV-PET). Corresponding planning target volumes (PTV) were generated, and separate treatment plans were then produced. For each patient, volumetric analysis of GTV-CT, PTV-CT and GTV-PET was performed to quantify the proportion of PET-avid disease that was not included in the GTV and PTV (geographic miss) if CT data alone were used for radiotherapy planning. Assessment of the cranial and caudal extent of the primary oesophageal tumour as defined by CT alone vs PET/CT was also compared.

RESULTS

The addition of PET information altered the clinical stage in 8 of 21 eligible patients enrolled on the study (38%); 4 patients had distant metastatic disease and 4 had unsuspected regional nodal disease. Sixteen patients proceeded to the radiotherapy planning phase of the study and received definitive chemoradiation planned with the PET/CT data set. The GTV based on CT information alone excluded PET-avid disease in 11 patients (69%), and in five patients (31%) this would have resulted in a geographic miss of gross tumour. The discordance between CT and PET/CT was due mainly to differences in defining the longitudinal extent of disease in the oesophagus. The cranial extent of the primary tumour as defined by CT vs PET/CT differed in 75% of cases, while the caudal extent differed in 81%.

CONCLUSIONS

This study demonstrates that if combined PET/CT is used for radiotherapy treatment planning, there may be alterations to the delineation of tumour volumes when compared to CT alone, with the potential to avoid a geographic miss of tumour.

3D conformal radiotherapy for gastric cancer--results of a comparative planning study

BACKGROUND AND PURPOSE

Many radiation oncologists are reluctant to use anteroposterior-posteroanterior (AP-PA) field arrangements when treating gastric cancer with adjuvant postoperative radiotherapy due to concerns about normal tissue toxicity, particularly in relation to the kidneys and spinal cord. In this report, we describe a multiple-field conformal radiotherapy technique, and compare this technique to the more commonly used AP-PA technique that was used in the recently reported Intergroup study (INT0116).

MATERIALS AND METHODS

Fifteen patients with stages II-IV adenocarcinoma of the stomach were treated with adjuvant postoperative chemoradiotherapy using a standardised 3D conformal radiotherapy technique that consisted of a 'split-field', mono-isocentric arrangement employing 6 radiation fields. For each patient, a second radiotherapy treatment plan was generated utilising AP-PA fields. The two techniques were then compared for target volume coverage and dose to normal tissues using dose volume histogram (DVH) analysis.

RESULTS

The conformal technique provides more adequate coverage of the target volume with 99% of the planning target volume (PTV) receiving 95% of the prescribed dose, compared to 93% using AP-PA fields. Comparative DVHs for the right kidney, left kidney and spinal cord demonstrate lower radiation doses using the conformal technique, and although the liver dose is higher, it is still well below liver tolerance.

CONCLUSIONS

3D conformal radiotherapy produces superior dose distributions and reduced radiation doses to the kidneys and spinal cord compared to AP-PA techniques, with the potential to reduce treatment toxicity.

Promising results of a cooperative group phase II trial of preoperative chemoradiation for locally advanced rectal cancer (TROG 9801)

PURPOSE

This article reports the overall survival, failure-free survival, local failure, and late radiation toxicity of a phase II trial of preoperative radiotherapy with continuous infusion 5-fluorouracil for rectal cancer after a minimum 3.5 years of follow-up.

METHODS

Eligible patients were those with newly diagnosed localized adenocarcinoma of the rectum, within 12 cm of the anal verge, staged T3-T4 and deemed suitable for curative resection. Radiotherapy (50.4 Gy in 28 fractions in five weeks and three days) was given with continuous infusion 5-fluorouracil throughout the course of radiotherapy.

RESULTS

A total of 82 patients were accrued in 13 months. The median follow-up time was 4.1 (range, 2.3-4.5) years. There were 55 males (67 percent) and the median age was 59 (range, 27-87) years. Patients were staged pretreatment as T3 (89 percent) and resectable T4 (11 percent). Endorectal ultrasound was performed in 70 percent and magnetic resonance imaging in another 5 percent. The four-year overall and failure-free survival rates were 82 percent (95 percent CI: 72-89) and 69 percent (95 percent CI: 58-78), respectively. The cumulative incidence of local failure at four years was 3.9 percent (95 percent CI: 1.3-11). Risk of failures, local and distant, has not reached a plateau phase.

CONCLUSION

This regimen can be delivered safely and without leading to a significant increase in late toxicity. It provides excellent local control and favorable overall survival. There is a need for longer follow-up than has commonly been used for the proper evaluation of failures after an effective regimen of preoperative chemoradiation.

Natural history of tumour-related sacral obliteration with nerve-root preservation

Benign aggressive bone tumours can present a dilemma when the definitive treatment options necessitate enormous and permanent functional deficits. Here, we present a case of a massive sacral giant-cell tumour causing dramatic skeletal obliteration, which was successfully treated with radical radiotherapy rather than ablative surgery. The excellent functional outcome highlights the importance of nerve-root preservation in selecting treatment modalities.

Oxaliplatin combined with infusional 5-fluorouracil and concomitant radiotherapy in inoperable and metastatic rectal cancer: a phase I trial

The aim of this study was to define the recommended dose of oxaliplatin when combined with infusional 5-fluorouracil (5-FU) and concurrent pelvic radiotherapy. Eligible patients had inoperable rectal cancer, or symptomatic primary rectal cancer with metastasis. Oxaliplatin was given on day 1 of weeks 1, 3 and 5 of radiotherapy. Dose level 1 was oxaliplatin 70 mg m(-2) with 5-FU 200 mg m(-2) day(-1) continuous infusion 96 h week(-1). On dose level 2, the oxaliplatin dose was increased to 85 mg m(-2). On dose level 3, the duration of the 5-FU was increased to 168 h per week. Pelvic radiotherapy was 45 Gray (Gy) in 25 fractions over 5 weeks with a boost of 5.4 Gy. Fluorine-18 fluoro deoxyglucose and Fluorine-18 fluoro misonidazole positron emission tomography (FDG-PET and FMISO-PET) were used to assess metabolic tumour response and hypoxia. In all, 16 patients were accrued. Dose-limiting toxicities occurred in one patient at level 2 (grade 3 chest infection), and two patients at level 3 (grade 3 diarrhoea). Dose level 2 was declared the recommended dose level. FDG-PET imaging showed metabolic responses in 11 of the 12 primary tumours assessed. Four of six tumours had detectable hypoxia on FMISO-PET scans. The addition of oxaliplatin to infusional 5-FU chemoradiotherapy was feasible and generally well tolerated. For future trials, oxaliplatin 85 mg m(-2) and 5-FU 200 mg m(-2) day(-1) continuous infusion 96 h week(-1) is the recommended dose when combined with 50.4 Gy of pelvic radiotherapy.

A phase I trial of preoperative radiotherapy and capecitabine for locally advanced, potentially resectable rectal cancer

The purpose of the study was to determine the maximum-tolerated dose (MTD) of oral capecitabine, combined with concurrent, standard preoperative pelvic radiotherapy, when given twice daily, from Monday to Friday throughout the course of radiotherapy, for locally advanced potentially resectable rectal cancer. Maximum-tolerated dose was defined as the total (given in two equally divided doses) oral dose of capecitabine that caused treatment-related grade 3 or 4 toxicity in one-third or more of the patients treated. Radiotherapy involved 50.4 Gy given in 28 fractions in 5 weeks and 3 days. Eligible patients had a newly diagnosed clinical stage T3–4 N0–2 M0 rectal adenocarcinoma located within 12 cm of the anal verge suitable for curative resection. Surgery was performed 4–6 weeks from completion of preoperative chemoradiotherapy. In all, 28 patients were enrolled in the study at predefined dose levels: 850 mg m⁻² day⁻¹ (n=3), 1000 mg m⁻² day⁻¹ (n=6), 1250 mg m⁻² day⁻¹ (n=3), 1650 mg m⁻² day⁻¹ (n=3), 1800 mg m⁻² day⁻¹ (n=8) and 2000 mg m⁻² day⁻¹ (n=5). The mean age was 62.3 years (range: 33–80 years). Five patients were female and 23 male. The median distance of tumour from the anal verge was 6 cm (range: 1–11 cm). Endorectal ultrasound was performed in 93% of patients. A total of 26 patients (93%) had T3 disease and two patients had resectable T4 disease. Dose-limiting toxicity (DLT) developed in one patient at dose level 1000 mg m⁻² day⁻¹ (RTOG grade 3 cystitis). Two of the five patients at dose level 2000 mg m⁻² day⁻¹ had a total of three DLT (grade 3 perineal skin reaction, grade 3 diarrhoea and grade 3 dehydration). Dose escalation of capecitabine was ceased at 2000 mg m⁻² day⁻¹ after reaching MTD. None of the eight patients at dose level 1800 mg m⁻² day⁻¹ developed DLT. All except one patient underwent surgery. A total of 15 patients had the clinical T stage reduced by at least one stage in pathologic specimens. Five patients (19%) achieved a pathologic complete response. We conclude that the MTD of capecitabine was reached at a dose level of 2000 mg m⁻² day⁻¹, given as 1000 mg m⁻² twice daily, from Monday to Friday throughout the course of preoperative pelvic irradiation of 50.4 Gy. For patients with resectable rectal cancer receiving concurrent, full dose radiotherapy, the recommended dose of capecitabine for further study is 1800 mg m⁻² day⁻¹ when given in this schedule.

Thallium-201 scintigraphy–a predictor of tumour necrosis in soft tissue sarcoma following preoperative radiotherapy?

AIM

Thallium-201 (Tl-201) scintigraphy in patients with malignant soft tissue tumours was evaluated to determine whether the images correlated with histological response to preoperative radiotherapy.

METHODS

We studied 54 patients, median age 32 (range 17-84) years, with non-metastatic, malignant soft tissue tumours diagnosed between 1996 and 2001. Thirty-eight patients had unoperated tumours and 16 patients had previous incomplete excisions. All patients received preoperative radiotherapy followed by surgery. No patient received chemotherapy as part of their initial management. Qualitative analyses of early phase (30 min) and late phase (4 h) Tl-201 scintigraphic images before and after preoperative radiotherapy were compared with the degree of tumour necrosis determined histologically.

RESULTS

In the previously unoperated group, all 38 patients had increased TL-201 uptake in the late phase of scanning prior to radiotherapy suggesting metabolically active tissue. In the previously excised group 11 patients had increased Tl-201 uptake in the late phase of scanning prior to radiotherapy. Following radiotherapy, patients with Tl-201 retention on late phase scans had a lower rate of necrosis than patients with minimal retention, p<0.0001. Following radiotherapy, 28 of 29 patients with minimal uptake on the late phase had 80% or more necrosis, while 24 of 25 patients with increased uptake on the late phase had less than 80% necrosis (p<0.0001). Patients with previously excised tumours who had thallium retention following radiotherapy demonstrated evidence of residual disease at surgery. All patients with incompletely excised tumours who had no thallium retention on late phase scanning after radiotherapy demonstrated no evidence of residual disease at surgery.

CONCLUSION

Thallium scintigraphy is a readily available investigative tool, which when used in conjunction with other imaging modalities in the assessment of primary and incompletely excised malignant soft tissue tumours, may predict histological tumour response to preoperative radiotherapy.

Phase II trial of continuous infusion carboplatin, 5-fluorouracil, and radiotherapy for localized cancer of the esophagus

The aim of this study was to determine the toxicity, response rate, failure-free survival, and overall survival in a treatment program comprising continuous infusion carboplatin, short in-fusion 5-fluorouracil (5-FU) and radiotherapy for localized carcinoma of the thoracic esophagus. To be eligible, patients were required to have Karnofsky performance status greater than or equal to 60, adequate organ function, and have received no prior therapy. Planned radiation dose was 50 Gy in 25 fractions over 5 weeks. 5-FU was to be administered commencing days 1 and 29 of radiotherapy, and given at a dose of 1 g/m2/d for 4 days as a continuous infusion. Carboplatin was to commence on day 1 of radiotherapy and be given throughout the period of radiation as a continuous infusion. The starting dose of carboplatin was 28 mg/m2/d. The protocol specified a 25% dose reduction of carboplatin if more than two of the first six patients experienced dose-limiting toxicity (DLT). DLT was defined as grade IV neutropenia lasting more than 7 days, grade IV thrombocytopenia, or any grade IV nonhematologic toxicity. All 23 patients in the study received protocol radio-therapy, except one who was given an extra 10 Gy. Seven patients received carboplatin at 28 mg/m2/d and 16 received 21 mg/m2/d. Hematologic DLTs were experienced by all of the seven patients receiving the higher dose. No patients in the low-dose group experienced hematologic DLTs, and only 2 of 16 ceased chemotherapy early because of myelosuppression. Three patients in the low-dose group experienced grade IV esophagitis but were able to complete protocol radiotherapy. Apart from esophagitis, nonhematologic toxicity was generally moderate or mild. Six patients had thrombosis complicating the central venous catheters. Endoscopy was performed in 21 patients (91%), with an overall complete response rate of 65% (CI: 43-84%) for the whole group or 71% (CI: 48-89%) for the endoscopically evaluated group. Estimated median failure-free survival time was 8.9 months (CI: 7.1-12.9), and estimated median overall survival time was 21.4 months (CI: 9.6 -35.4). Carboplatin at 21 mg/m2/d as a continuous infusion may be given safely in combination with short infusional 5-FU and radiotherapy for localized carcinoma of the esophagus. This combination has resulted in response data comparable to that of larger studies of cisplatin-containing regimens and warrants further study, ideally in a phase III randomized controlled trial.